What's up, internet? I'm Tim Steedman, and this is Get Psyched with me, Tim Steedman. Welcome to the official Get Psyched AP Psychology Ultimate Exam Cramathon Extravaganza updated for the 2024 CED TM. Yeah, it's a ridiculous name, but honestly, so is thinking you can cram five months of AP psychology into one video. Now, look, if you've been keeping up with class, this video is your final tuneup. You're going to crush it. But if this is the first time you've looked at anything psychology related since like, I don't know, November, bold move, my friend. Respect the hustle. But let's be real, this video is not going to magically teach you the whole course in an hour and 30 minutes. That's not what it's for. This is a review. It's meant to refresh what you've already learned, fill in a few cracks, and make you go, "Oh, I really did know that." So, if you're here hoping this will carry you from a zero to a five, I admire your confidence. But maybe also go check out my full unit review videos, you can actually start with cognition and look for the part on the spacing effect. It'll give you a real good idea of how this might go for you if you don't. All right, enough talk. How about we get into it? So, we are starting with these science practices, and what good is a get psych review video if we're not exploiting our good pal Doug. So, Doug has a theory, and a bold one at that. He swears that listening to his favorite music helps him focus while studying. So, naturally, he decides this needs to be tested. He comes up with a name for his study, Sweet Beats for Cognitive Feats. You know what? That's actually a pretty dope name. Got to give you credit there, Douggee. But anyways, something cool about Doug's little study is that you could apply all kinds of modern psychological perspectives to explain what he's doing. Like, if he thinks he's been conditioned to associate music with studying, well, that's a behavioral approach. If he believes the music helps him process information more effectively, we're talking the cognitive perspective. If he secretly links music to a childhood sense of safety and calmness, welcome to the psychonamic perspective. Or maybe he just wants to feel good and unlock his full potential and music is his way of achieving this. Boom. Humanistic. If we zoom in on how music affects his dopamine levels and brain activity, that's going to be the biological approach. Zoom way out and someone might argue humans evolve to respond to rhythm. A classic take on evolutionary psychology. And finally, if all of his friends study with music and it's just the expected norm of the society Doug lives in, that's going to be the socioultural perspective. No matter how you slice it, Doug's jamming out and psychologyy's got something to say about it. And it's not just about Doug's preferences either. His whole environment plays a role. Everyone he knows studies with music on. His friends rocking out to some Blink 182. his sister T. Swift, that kid from AP Calp BC, Beethoven maybe. I don't I don't really know. I'm not a mathematician. In fact, as you probably already know, numbers terrify me. But the point is, cultural norms might be influencing Doug more than he even realizes. So, how about we talk about Doug's cognitive biases because, well, Doug's got quite a few. For starters, he has a classic case of confirmation bias. He only notices the times music helps him focus and ignores the times he spent 45 minutes of dedicated studying time shuffling through his Spotify playlist. Then there's hindsight bias. If Doug studied with music and then got a good grade, he might think, "I knew it. I knew music was going to help. That was obvious from the start." Yeah, okay. Sure you did, Douggee. Because rumor has it your buddy Skeer Valentine was talking to Roger Clauss about how you had doubts of your own about the effectiveness of listening to music as a studying technique. What up with that? And of course we have a clear case of overconfidence bias. This can be seen with Doug thinking he's about to run the greatest psychological study of all time, which could and probably will hinder his overall performance conducting the study. It's kind of like that kid on your middle school soccer team who thought they were the second coming of Cristiano Ronaldo overestimating their own skills ultimately leading to poor performance. Yeah, I am talking about you. But here's the thing. Psychology is meant to understand behavior, not judge it. So if Doug suddenly decided that people who study in silence are less intelligence, he'd be making a big mistake. That's a straightup mislication of a psychological concept. Just because something feels true to you doesn't mean it applies to everyone else. And that's what science practice one is really all about. Taking psychological concepts, theories, and perspectives and using them to explain what's happening in the real world. Doug isn't just thinking about psychology, he's trying to actually use it. Now Doug's ready to prove his theory, but before jumping into an experiment, he stops to think about his options. He could do a naturalistic observation where he sits in the library and just watches people study with and without music and then tracks their performance on tests. He could run a case study where he follows around one kid who listens to music while studying and then documents their habits in detail. Or he could even try a meta analysis where he would just combine results from a bunch of previous studies to look for a trend that may answer his question. Doug ultimately decides on a correlational study. He wants to see if there's a relationship between listening to music while studying and your GPA. To collect data, he builds a survey. And let's be real, it's not a well-crafted IRB approved masterpiece. It's just three questions that he wrote down on his late math homework. You might want to turn that in, bud. So, he sends a survey out to his friends and asks, "Do you listen to music while studying? You think it helps you focus? And what's your GPA?" Boom. data science, right? Well, not quite. Doug isn't manipulating anything. He's just gathering info, which makes this non-experimental research. But here's where things start to fall apart. Since he's relying on the answers of high school students, he runs into some self-report bias where people might exaggerate, guess, or just try to sound good while completing the survey. On top of that, he sees the social desiraability bias pop up. Nobody wants to admit that instead of studying, they spend a majority of their time watching scripted Tik Toks or binge watching terrible Netflix series. As Doug is analyzing his data further, he begins to see a trend. People who listen to music while studying have better grades. Well, that's good and all, but now he has another issue, which is the directionality problem. So, does music cause better grades, or are those with good study habits just more likely to listen to music while studying for some other reason? And let's not forget the third variable problem. Maybe something like motivation or natural intelligence is influencing both variables being studied. Doug realizes he can't prove anything with correlation. So naturally, he escalates. It's time for a full-blown experiment, baby. His hypothesis, if students listen to preferred music while studying, they'll perform better on a quiz. It's a good one. It's falsifiable, which means someone else could test it and potentially disprove it. and it can be replicated, meaning someone else could try the same study to see if they get the same results, which would add to the validity of Doug's results. He goes on and identifies his independent variable, which is music or no music, while his dependent variable will be performance on an AP psych quiz. But did Doug remember to include an operational definition, like what exactly counts as preferred music and how is he scoring this quiz? Spoiler alert, he didn't. Anyways, any quality experiment is going to require some participants. So, Doug grabs 20 classmates to be in the study. Are they randomly selected? Nah. He picks whoever's hanging out in the bathroom. Convenience sampling at its finest. He's trying to generalize his results to all high school students, but this isn't a representative sample at all, so he's going to have a tough time with that generalization. There's also no random sampling, so he can't confidently apply his results to the broader population. And that's what we call sampling bias. When the people you picked don't represent who you're trying to study. Well, Doug goes ahead with the experiment anyways. He splits the bathroom dwellers into two groups. The experimental group listens to music and then the control group just gets silence, but he doesn't use random assignment. And now we've got even more confounding variables on our hands. Doug then goes on and tells everyone exactly which group they're in. No single blind, no double blind, and way too much experimental bias. I will say though, I gotta give credit where credit is due. Doug did add a pretty cool twist to his study by adding an additional group who would receive a placebo. So Doug told these guys that they will be receiving focus enhancing frequencies or something. All in order to see if a placebo effect would occur. After the quiz, Doug asks everyone how focused they felt using a liyker scale. The participants marked on a scale of 1 to 10 how focused they were during the test, giving Doug some solid quantitative data, but Doug also wanted some personal insight. So, he decided to add structured interviews to ask follow-up questions, giving him some more qualitative data. Now, let's talk the ethics of Doug's experiment. Because, as you know, psychological research is required to follow ethical guidelines. Something Doug may have forgotten about. Doug didn't get informed consent. didn't debrief anyone, didn't ensure confidentiality or anonymity, and has never even heard of an institutional review board. Also, he may or may not have planted a confederate in the music group just to hype it up and sway results. Did Doug submit his study for peer review? Of course not. He posted it on Instagram with the caption, "Science, nailed it." No, not really, bud. But Doug did manage to stumble through just about every important part of research design. And that's what science practice 2 is all about. So not a total failure, I guess. But Doug's not done just yet. Let's see how he does when it's time to analyze all the data. So Doug's experiment is done. He's got the quiz scores. Now time to crunch some numbers, which of course means time for Doug to attempt to interpret all this data. First up, central tendency. Doug wants one number that represents all of his data. So, he calculates the mean, median, and mode. It's going okay until he realizes one participant got a zero because they fell asleep mid quiz. Well, now the mean is wrecked, and Doug learns that outliers matter. Doug then decides to check for variation in the scores, or how spread out the data is. He calculates the range, which is the difference between the highest and lower scores, and realizes it's way bigger than expected. He realizes the scores are all over the place, takes it a step further, and decides to calculate the standard deviation to see how far the scores deviate from the mean. But Doug doesn't know how to do that. So, he quickly gives up and tries something else. Doug takes the data and makes a graph, hoping for that sweet, sweet normal curve. You know, that beautiful symmetrical bell shape that researchers love oh so much. Well, it's no one's surprise, but Doug's, I guess, he didn't get this. What he gets instead is chaos. The music group scores, positively skewed curve. Most did well, but one guy tanked it. No music group, negatively skewed curve. Most did poorly, but one overachiever crushed it. Then there's the weird case where two different clusters of scores pop in the same group. Some students scored really high, others scored really low, but hardly anyone landed in the middle. That's a biodal distribution, which is a graph with two peaks instead of just one. And it usually means your group is made up of two very different types of people, like high performers and low performers responding differently to the same condition. Doug then starts looking at individual student scores. Seeing an 85%, Doug thinks to himself, "Nice, that guy got an 85. That's like a B, right?" What Doug didn't know was that he was just looking at the percentile rank. That actually means the participants scored better than 85% of the group. Oh, and remember that overachiever in the no music group? Well, the next quiz that was administered, they scored much closer to the class average. That's regression to the mean, which is when extreme scores tend to drift back toward average. Now Doug's starting to feel confident. So, he wants to prove music made a difference. So, he calculates a correlational coefficient between music preferences and quiz scores. He gets a positive 0.4. Thinking to himself, that's like a 40%. Tough luck for this dum dum. Well, no, Doug. We literally just went over this with the percentile rank. That 0.4 tells us the strength and direction of the relationship. Not a grade. He also throws around the term effect size, but he thinks it has something to do with how loud the music was, but yeah, it doesn't. Effect size tells us how much of an impact the independent variable actually had, regardless of whether the results were statistically significant. And speaking of which, Doug proudly announces his study is statistically significant because he just feels like the results were important. But nope, doesn't work that way. Statistical significance means the outcome probably wasn't due to chance. And that's something you can determine with real data, not just because you're feeling it. So Doug thinks he's discovered something groundbreaking, but mostly he's just rediscovered what every stats unit has already taught us. And that's what science practice 3 is all about. Interpreting psychological data not only to explain behavior, but to also provide evidence for these explanations. All right, Doug's done. He built a survey, ran an ethically questionable experiment, graphed his chaos, and posted it all online like it was a peer-reviewed masterpiece. And with all of these questionable decisions in Doug's research design, I think it's best if we part ways for now. Remember, Doug, these guys actually want to pass the test. All right, so now we're talking about science practice 4, argumentation. Now, this one's different. You're not analyzing data or applying terms to a scenario. You're making a claim and backing it up with psychology. On the AP exam, this could be agreeing, disagreeing, or modifying a statement on human behavior. Now, it's important you just don't pick one of these and call it a day. You have to support your position using relevant psychological concepts and evidence. If it's about screen time and attention spans, don't just say, "I just feel like that's true." You've got to reference research. You've got to name theories. You've got to connect your ideas clearly. Remember, the College Board is looking to see that you can make a clear, defensible claim. Use psych terms and concepts as evidence, and explain how your evidence supports your argument. So, yeah, this isn't just about opinion. Psychologists don't argue with anecdotes. They argue with actual data. So, we've made it through all of the science practices, the stats, the study designs, the doug, and you now know officially how to think like a psychologist. But now, it's time to start thinking about what psychologists actually study. And it all starts here with the body's original overachiever, the brain. Welcome to unit one of AP psychology, the biological basis of behavior. Here we're talking neurons, neurotransmitters, brain structures, and just enough vocabulary to make your frontal lobe twitch. All right, so we're going to start at the root of all behavior, taking a look at why we are the way we are. The classic nature versus nurture debate. So nature refers to the influence of our heredity, which is the DNA we inherit from our parents. Our genes create a predisposition or a tendency to develop certain traits or disorders. It's not a guarantee, just an increased likelihood. For example, someone might have a genetic predisposition for anxiety. But whether or not it actually develops, that's where nurture comes in. Nurture is the influence of the environment. Everything from how we're raised to the culture we grow up in. The evolutionary perspective takes a step back and asks, why would a behavior help humans survive and reproduce? It's rooted in natural selection, which is the idea that traits that increase survival are more likely to be passed on. You know, fear responses, social bonding, even phobias. Evolutionary psychologists argue those behaviors were all adaptive. But not all applications of evolutionary thinking have aged well. Which brings us to eugenics, a dark chapter in psychology where people tried to control who should and shouldn't reproduce in order to improve the human gene pool. It's unethical. It's discriminatory. And it's just not science. Now, to understand how nature and nurture interact, psychologists rely on research such as twin studies, family studies, and adoption studies. These methods help us estimate heritability, which is how much variation in a trait is due to genetics. So, yeah, nature and nurture are always working together. It's not just one or the other. It's going to be both. Now that we've talked about where behavior comes from, let's break down the system that controls all of it, the nervous system. At the top is the central nervous system or CNS. It includes two major players, the brain and the spinal cord. The brain is your command center. It's going to be processing information, making decisions, and just keeping you alive. The spinal cord handles basic reflexes and acts like the nervous systems highway, sending messages to and from the brain. Outside the CNS, we've got the peripheral nervous system or PNS, which connects the CNS to the rest of the body. The PNS has two branches. The sematic nervous system, which controls voluntary movement. So when you choose to raise your hand or walk to the fridge, that's sematic. The autonomic nervous system, on the other hand, is going to handle involuntary functions like heart rate and digestion. You know, the stuff your body does without asking you first. And the autonomic system has two systems of its own. First, we have the sympathetic nervous system, which kicks in during stress. It's your fightor-flight response, where your heart rate goes up, your digestion slows down, and adrenaline starts to kick in. The parasympathetic nervous system, on the other hand, is your rest and digest mode. It calms the body down, slows the heart, and gets everything back to normal after all the chaos. Together, these systems keep you balanced, responsive, and most importantly, alive, even when you're not even thinking about it. Now, let's zoom in, like weigh in, to the building blocks of everything your brain and body do, the neurons. A neuron is a specialized cell that sends and receives information throughout the nervous system. But it doesn't work alone. It's supported by gal cells, which act like the neurons pit crew, nourishing, protecting, and insulating them. There are three types of neurons you should know about. We have sensory neurons that carry messages into the brain and spinal cord. Your motor neurons, well, they're going to carry instructions out to muscles and glands. And then interneurons are the middlemen, processing information within the brain and spinal cord. These three neurons work together in a reflex arc, which is a quick automatic response to a stimulus that doesn't even require the brain, like pulling your hand away from a hot stove before you've even realized what's happening. Now, here's how a neuron fires a message. So, when the neuron is inactive, it's at its resting potential, which is just a stable negative charge inside the cell. If the stimulus threshold is reached, the neuron fires according to the all ornone law. You know, it either goes or it doesn't. No half sends. Once it fires, depolarization occurs where the inside of the cell becomes positively charged. That spark of electricity moving down the axon. That's the action potential. After firing, the neuron enters a refractory period or a short break where it can't fire again until it resets. Neurotransmitters are released into the syninnapse and after their job is done, they're either broken down or reabsorbed through a process known as re-uptake. Now, if this process doesn't go according to plan, things can go wrong. In multiple sclerosis, the immune system attacks the myelin sheath around the axons, disrupting communication. Myastinia gravis is an autoimmune disorder that blocks signals from nerves to muscles causing weakness. Now, let's focus on our neurotransmitters, which are the chemical messengers of the brain. Some carry excitatory messages where they increase the likelihood that the next neuron will fire an action potential, while others carry inhibitory messengers. They're going to decrease that likelihood. The major neurotransmitters that we need to know about are going to be dopamine, serotonin, norepinephrine, glutamate, GABA, acetylcholine, endorphins, and substance P. So, we've covered the nervous systems electrical messaging, but your body has another system for sending signals, just a little bit slower. Welcome to the endocrine system, which is our body's chemical messaging system. It sends hormones through the bloodstream to regulate things like growth, metabolism, mood, and stress. The major hormones that are fair game for the AP test is going to be adrenaline, leptin, ghrein, melatonin, and oxytocin. Now, let's talk about psychoactive drugs, which are substances that alter brain function, mood perception, andor behavior. These drugs either mimic or block neurotransmitters. An agonist is a drug that mimics a neurotransmitter or enhances its effects. An antagonist is a drug that blocks or inhibits the action of a neurotransmitter. While a re-uptake inhibitor is going to block re-uptake. Drugs can be grouped into four main categories. We have stimulants like caffeine or cocaine, depressants like alcohol, hallucinogens such as marijuana, and then opioids like heroin, which as you probably know, can be extremely addictive. And speaking of addiction, let's hit the three big terms that usually show up together when you're talking about drugs in an educational setting. Addiction is a compulsive drug use despite the negative consequences it brings. Tolerance is when more of a drug is needed to produce the same effect. and withdrawal are symptoms that occur when someone stops using a drug that they've grown a dependence on. And yes, all of these terms are fair game on the AP psych exam. So, we've zoomed in on neurons. Now, let's zoom back out a little and talk about the boss of the operation, the brain. And trust me, it's got layers, just like ogres and onions. We'll start at the base, the brain stem, which is your most basic survival center. It controls automatic functions like breathing and heartbeat. One part of the brain stem is the medulla which handles things like heart rate, blood pressure, and respiration. It's the keep you alive part of the brain. Just above that is the reticular activating system or reticular formation. That's your brain's attention filter. It regulates alertness and consciousness. Damage here, you're out cold. Behind that sits the cerebellum, which is your balance and coordination center. Think of it like your internal gyroscope. It helps with movement, posture, and even procedural memory. Above the brain stem is the lyic system, aka the emotional control center, which also plays a major role in memory and motivation. At the center of the lyic system is the phalamus, which is your brain's sensory switchboard. It takes sensory information and routes it to the right part of the cortex, except for smell. Smell skips the line. We'll talk about that later. The hypothalamus is tiny but mighty. It regulates hunger, thirst, body temperature, and links the brain to the endocrine system. It also controls the pituitary gland, which is the master gland of the endocrine system, sending hormones out to the rest of the body. Just remember, the hypothalamus is responsible for the four Fs of survival. We've got fighting, fleeing, feeding, and sexual functioning. The hippo campus helps form long-term memories, especially declarative ones. Without it, you can't store new memories. Think 10-second Tom from 51st Dates. Then there's the amydala, which processes emotions like fear and aggression. It's like your own biological alarm system. Now, let's move up to the cerebral cortex, the brain's outermost layer. It's what makes us uniquely human. Higher level thinking, planning, and decision-making all take place here. The cortex is split into four loes with each lobe being divided by the corpus colossum which is a thick band of nerve fibers that connects the left and the right hemispheres of the brain allowing them to communicate. The occipital lobe processes visual information. The temporal lobe handles auditory input, language comprehension and memory. The parietal lobe processes touch and spatial awareness. The smata sensenty cortex inside the parietal lobe registers body sensations like pressure, temperature, and pain. Then there's the frontal lobe which makes up your personality, judgment, and reasoning center. Inside the frontal lobe, the preffrontal cortex deals with decision-m, impulse control, and thinking ahead. Also in the frontal cortex, the motor cortex controls voluntary movement. Now, how about we talk language for a second? In the left hemisphere we find Broca's area which controls speech production. Damage to it causes Broca's aphasia where you know what you want to say but can't get the words out. Verici's area is responsible for language comprehension. Damage there causes Viciz aphasia where you can speak fluently but what you're saying doesn't make sense or you have trouble comprehending what others are trying to say to you. This is where cortex specialization comes in where different parts of the brain are specialized for specific functions. We also have contrateral hemispheric organization where the left hemisphere controls the right side of the body and vice versa. In severe cases of epilepsy, doctors might perform a split brain procedure which involves severing the corpus colossum to stop seizures from spreading across the hemispheres. Now, split brain studies revealed some pretty wild things about how the two hemispheres process information separately. Like the left hemisphere is usually more language dominant, while the right is better at spatial and visual tasks. Even when the brain is damaged, it can often rewire itself. That's called brain plasticity, or the brain's ability to adapt. Structural plasticity is about growing new connections, while functional plasticity is about shifting functions from one area to another. And finally, let's take a look at how we study the brain. Well, we have two key brain scans we need to know for AP psychology. The EEG measures electrical activity through brain waves. Great for sleep studies. And the fMRI shows brain activity by tracking oxygen use in real time. Fancy stuff. Also, like some magnets and stuff are used there. They like spin around your head really fast. Oh, and let's not forget lessioning, where researchers study damaged brain tissue to figure out what certain areas might do. Think like Phineas Gage. Now, let's move on to the next part of our biological basis unit, dealing with our various states of consciousness. At its core, consciousness is your awareness of yourself and your environment. We're mostly concerned with the sleepwake cycle here, looking at what happens when consciousness starts fading out for the night. Sleep is guided by your circadian rhythm, a biological clock that regulates things like temperature, alertness, and when you start to feel tired. It's why jet lag and working the night shift can totally throw you off. Your body's clock is out of sync with the world around you. As you fall asleep, you pass through several sleep stages, including NRM and REMM. Stage one, NRM is super light. You're half awake, and this is where those trippy hypnogogic sensations can hit. You might feel like you're falling, jerk awake, or think you heard something. As we enter stage two, NREMM, brain waves continue to slow down, but we start to see sleep spindles and K complexes. Stage two is still considered light sleep. And our final stage of NRM sleep, stage three, NRM, is deep sleep, hard to wake up from and crucial for physical restoration. Then comes sleep, also called paradoxical sleep. During this stage, your body is paralyzed, but your brain is incredibly active. This is the stage where most dreams happen. Miss out onm for a few nights. Your brain will enter something called rebound where it makes up for the lost dream time with longer, deeperm sessions. So, you may be wondering why do we sleep or even dream for that matter? Well, there's a few theories. The restorative theory says sleep helps the body recover and repair. The consolidation theory suggests sleep strengthens memories. And the activation synthesis theory argues that dreams are just the brain's way of making sense of all this random neural firing that occurs. What happens when we don't get enough sleep? Well, that's called sleep deprivation. And yeah, it's a problem. Even mild deprivation can wreck your mood, memory, focus, and immune system. If you've pulled an allnighter before an exam or stayed up way too late playing whatever video game is popular right now, well, you probably know what I'm talking about. Sometimes sleep deprivation is not caused by poor sleep habits, but diagnosed disorders. We have insomnia, which involves trouble falling or staying asleep. Sleep apnea is when breathing repeatedly stops during sleep. Narcopsy is going to be when someone experiences sudden uncontrollable sleep attacks during the day. REMM sleep behavior disorder is acting out your dreams because the body isn't entering a state of sleep paralysis as it should be. And some nambilism or sleepwalking is our final one. And no, you don't do parkour or drive a car while you're sleepwalking for the most part at least. I think there may have been some isolated incidents. Now, sleep may feel like doing nothing, but psychologically it's one of the most fascinating states we enter. And next up, our final topic for the biological basis unit, sensation, where we figure out how your body even knows what's going on in the world. So, here's the deal. Your brain can't interact directly with the outside world. It relies on your senses to gather raw data and send it up for processing. You smell a pizza with delicious pineapples on it. Your sensory receptors picked up chemicals in the air and converted them into signals your brain could understand. That process, that's called transduction. And that's happening all day, every day, 258 or whatever. Now, how strong does that pizza smell have to be for you to even notice it? Well, that's going to be your absolute threshold or the minimum amount of stimulation needed to detect something at all. Below that, your body ignores it. Above it, you may notice it, maybe even get hungry. But what if someone slowly turns up the volume on a song? At what point do you say, "Hey, did that just get louder?" Well, that's going to be your just noticeable difference, and it depends on how intense the original stimulus was. That's the idea behind Weber's law, where stronger stimuli require bigger changes to detect. Now, let's say you're wearing socks, which usually people are. Anyways, after a few minutes, you don't really feel them anymore. That's sensory adaptation. Your brain's like, "Got it. Not important anymore. Not going to waste my precious resources letting you know about it." Little passive aggressive there brain, but okay. Anyway, sometimes your senses even team up, like how smell boosts your experience of taste. That's going to be something called sensory interaction. And for a rare few, things go next level weird. You know, imagine hearing music and seeing colors. That's called synesthesia. And yeah, it's as wild as it sounds. So, now let's move on to the various senses, starting with vision. Vision starts when light enters the eye and passes through the lens, which focuses that light onto the back of the eye. The eye adjusts shape depending on distance, a process called accommodation. If the lens focuses light in front of the retina, you've got nearsightedness where distant objects are blurring. But if it focuses light behind the retina, that's where we see far-sightedness where you struggle to see things close up. The light eventually hits the retina, the layer of photo receptors that transduces light into neural signals. Right at the center of the retina is the phobia, packed with cones, which are the cells responsible for color vision and sharp detail. You've got three types of cones, each tuned to respond to a specific wavelength of light. Long red wavelengths, medium green wavelengths, and short blue wavelengths. This is the basis of the tri chromatic theory of color vision. But there's also the opponent process theory of color vision, which explains how we process color pairs like red verse green or blue verse yellow. It's why staring at a red image too long can lead to a green after image. In dim light, your rods kick in, helping you detect black, white, and movement, but not color. All the visual info is gathered by ganglen cells, which bundle together to form the optic nerve. where that nerve exits the retina, there are no receptors, creating a blind spot, your brain fills in automatically. When visual processing doesn't work as intended, things get interesting. And we've already talked about nearsightedness and far-sightedness, but let's take a look at a few more. So, people with diromatism or monochromatism are missing one or more types of cones leading to color blindness. Someone with proopagnosia or face blindness might see faces, but the brain can't recognize them. And with blind sight, a person with damage to the visual cortex might not be able to see, yet they can still navigate obstacles or detect movement in a ball being thrown their direction. Next up, sound. Sound travels as vibrations through the air and hits your eardrum, which sends those vibrations through a chain of tiny bones into the cookia. The cookia is a spiral-shaped structure in the inner ear. Inside the cookia is the baselor membrane which is lined with these tiny hair cells which are going to be your sensory receptors for hearing. They do a little dance in response to vibrations triggering neural signals your brain can understand. Pitch is going to be how high or low a sound is and amplitude is going to be how loud it is. Loudness is just bigger waves while pitch depends on frequency. Now how we interpret pitch? There are three main theories. The place theory says different pitches simulate different spots along the cookia. This explains high frequency sounds best. The frequency theory says the whole cookia vibrates at the same rate as the sound wave. This fits better for low frequency sounds. And the volley theory fills in the gap. Neurons take turns firing in quick burst to handle mid-range frequencies. Now, have you ever wondered how you can tell where a sound's coming from? Well, that's sound localization, where your brain compares the differences in time and intensity between your ears to triangulate the source. When hearing goes wrong, it comes down to where the damage is. Conduction deafness is when something in the outer or middle ear isn't working right, like a damaged eard drum or broken bones. Sensory neural deafness is a bit more serious, being damaged to the inner ear or auditory nerve itself. Either way, your brain's not getting the full message. Next up, we have the chemical senses of taste and smell. Let's start with smell, aka old faction. You breathe in airborne molecules and they bind to hair cell receptors high up in your nose. Those signals go to the old factory bulb and then straight to the oldactory cortex, totally bypassing the phalamus, unlike every other sense. And that shortcut, it's why smells hit memory and emotion so hard. Some researchers believe pherommones, which are chemical signals picked up through smell, might subtly affect human behavior. Now, the juryy's still out, but it's a big deal in other species. Now, we're going to talk taste or gustation. So, your tongues covered in taste buds, each loaded with receptor cells to detect different chemical flavors. So, we've got six basic tastes. sweet, sour, salty, bitter, umami, and the newest one, olioagustus, which picks up fat content. These signals get processed in the gustatory cortex, which helps your brain say, "Yep, tastes like pizza." But not all tongues are created equal. A super taster has more densely packed taste buds, often super sensitive to bitterness. Medium tasters are average, and non-tasters, well, fewer taste buds, mild reaction. So that's your friend who dumps hot sauce on literally everything. Also, if you've ever noticed food tasting flat when your nose is stuffed, that's because smell and taste are besties. Your old factory system boosts the flavor experience. No teamwork, no taste. Now, let's move on to touch and other body senses. So, touch starts with receptors in your skin, each tuned for different jobs. Mechano receptors detect pressure and texture. Thermoceptors sense temperature changes. and no receptors. They respond to pain, damage, inflammation, or even potential threats. When these receptors fire, they send signals through the spinal cord to the brain smata centensory cortex where touch is processed and mapped out. But pain, that's its own thing. The gate control theory says your spinal cord acts like a bouncer. It either lets pain signals through to the brain or blocks them based on competing input. That's why rubbing your elbow after bumping it can actually reduce the pain. It's closing the gate. Then there's phantom limb sensation when someone who's lost a limb still feels pain or movement in that missing part. It happens because the brain's body map doesn't update as fast as the body does. Now pain is not just about tissue damage. It's about how the brain interprets the signals. Mood, attention, expectation, all of that can change how intense the pain feels. And that's what makes touch one of the most physical and most psychological senses we've got. You're not just aware of the world. You're aware of yourself in it. That starts with the kinesesthetic sense, which is your ability to sense the position and movement of your body parts. You don't need to look at your arm to know it's raised. You feel it. Now, this happens thanks to propyroceptors in your muscles, tendons, and joints that constantly feed your brain updates about limb position and tension. But balance, that's all about the vestibular sense. Inside your inner ear are three fluid fil tubes called semic-ircular canals. As your head moves, fluid sloshes around and bends hair cells inside the canals. Those cells send info about rotation and acceleration to the brain, helping you stay upright. Spin in a circle and stop. You're probably going to feel dizzy. That's the fluid still moving after your body's already stopped. Your vestibular system is still playing catch-up. These systems work together seamlessly until they don't. That's when you trip over nothing, feel motion sick, or miss a step your body swore was there. Balance and body awareness might not get the spotlight like sight or hearing, but without them, the world would feel a whole lot shakier. All right, so you sensed the world in unit one. Now, let's talk about how your brain interprets all this information. That's going to be perception. Organizing and making sense of all the sensory info hitting you all at once. Sometimes your brain builds the picture piece by piece, which is bottomup processing. You're starting with raw details and figuring out what you're looking at, like when you see a weird smudge on the wall and slowly realize, "Oh, just a spider." Other times, your brain fills in the gaps using experience and expectations. That's top- down processing. You know what you're seeing before all the details hit. Thanks to your schemas, which are just your mental frameworks built from past experiences. We've talked about them a little bit in previous units. No, we haven't. We're going to be talking about them in further units. My bad there. Those schemas shape your perceptual set, which is a readiness to perceive something in a certain way, like looking at what's on the screen and reading the cat. even though both the H and the A are represented by the same symbol. That's your brain using context effect to help decode it based on the surrounding info. And that's top- down processing in action. Now, let's talk about gestalt psychology, which is the idea that the whole is greater than the sum of its parts. Your brain wants to group things together and find meaning even when it's not technically there. So, I want you to check out the image on the screen. You're seeing the letter G even though it's not entirely drawn out. That's closure. Your brain fills in the missing pieces. But before your brain even gets to closure, it's doing something else first. It's separating the letter from the background. That's going to be the basis of gestalt psychology, which is the figure ground relationship. It's your brain deciding this is the part to focus on, and everything else is just background noise. Other guest principles include the proximity of how close things are grouped together and how similar they look. These are your brain's visual shortcuts, and they work fast. Now, how about we shift our attention to, well, attention. So, you're constantly bombarded with stimuli, but your brain can't focus on everything. So, it's going to have to filter some stuff out. That's going to be selective attention, which is when we focus on one thing while ignoring the rest. Now, I want you to imagine that you're in a loud, crowded room when you start hearing your name from across the room. Well, that's going to be the cocktail party effect, which is how your attention can shift automatically to something personally relevant. But attention is limited and sometimes it totally fails us. Ever miss a huge change in a scene because your attention was somewhere else? That's change blindness and you know your brain doesn't register the change unless it was already focusing on it. Now let's talk depth perception or how your brain creates a 3D view from 2D info on your retina. With binocular cues, you're going to need both eyes. So here we have things like retinal disparity which compares the slightly different images from each eye. The bigger the difference, the closer the object. Convergence is how much your eyes turn inward to focused. The more inward equals the closer the object is. With just one eye, your brain relies on moninocular cues. The ones we need to know here are relative size, relative clarity, interposition, texture gradient, and linear perspective. Another cool thing your brain knows things stay the same even when they look different. That's perceptual constancy. Like when a door swings open, but you still know it's a rectangle. Shape and size constencancy keep the world stable as things move or change angles. Finally, your brain's also real good at seeing motion, even when there isn't anything there. That's apparent movement, like blinking lights that look like they're moving in sequence or when still images animate in your brain. And just like that, you're not just sensing the world, you're decoding it in real time. Now, are you ready to shift gears into thinking, problem solving, and decision-m? Yay. All right. Awesome. Let's keep it rolling. We can start with thinking. So, we organize our ideas using concepts, which are just mental categories that help us group similar things. Like the concept of dog includes everything from Chihuahua to Great Danes. But when you hear dog, you probably picture one specific example. That's going to be your prototype, which is just your personal mental best example of a specific category. For me, by the way, it's my beautifully plump Corgi Stark. Love you, buddy. These concepts build into bigger frameworks, aka schemas. They help you predict what'll happen in familiar situations. If you walk into a classroom, your schema tells you there will be desks, a teacher, probably someone forgetting a pencil or their laptop. We can adjust our schemas through two processes. First, we have assimilation, which means adding new info into existing schemas. Then we have accommodation, which means changing your schema to fit the new info. Like if you thought all birds could fly, but then you meet a penguin, you might need to accommodate when solving problems. Some people go full robot mode, step by step, using an algorithm. It'll get you the right answer eventually. Others use heristics or mental shortcuts. They're faster but more errorprone. Two big heristics are the representative heristic and the availability heristic. The representative heristic is judging based on how well something fits your prototype. Like assuming a quiet kid in glasses is more likely to be a mathlete than a football player, even if that's statistically unlikely. And then we have the availability heristic, which is judging based on how easily examples come to mind. If you just saw a news story about a plane crash, you might think flying is super dangerous, even though it's safer than driving. Unfortunately, in problem solving and decision-making, sometimes we get stuck. A mental set is when you keep approaching a problem the same way, even if it's not working. This is kind of like using the same study method that you used on the last five tests you failed, and then you sit there wondering why you can't pass. Or there's priming, where recent exposure to certain ideas influences your thoughts. You see the word yellow, and then you're faster to recognize banana. And how you present information matters, too. That's framing. When referring to an experimental treatment, saying 90% of patients survive sounds way better than 10% of patients die, even though they mean the exact same thing. The gamblers's fallacy is believing past events influence future chances. Last four coin flips have been heads. The next has to be tails. The sunk call is sticking with something just because you already put time or money into it. Even if it's clearly not working, like finishing a TV show you used to be a big fan of, but you ended up not liking anymore as the seasons went on. But feeling the need to get that closure no matter how bad the last season is. Yeah, talking about you, Game of Thrones. I've never felt so betrayed in my life. Don't even get me started on George R. Martin. Your executive function helps you manage all this thinking. It's the brain's control center, organizing thoughts, planning, and helping you stay focused. Your executive function contains your working memory, cognitive flexibility, and inhibitory control. Now, let's flip the script. Not all thinking is about solving problems the right way. Creativity is about new ideas and seeing things differently. It's driven by two types of thought. Divergent thinking is generating multiple ideas or solutions like brainstorming all the ways you could use a paper clip in ways not just for paper. Conversion thinking on the other hand is zeroing in on the single best answer. Standardized tests all about convergent thinking. Now the best thinkers such as myself can flip between both depending on the challenge. But even most creative minds hit roadblocks. Functional fixedness is when you can't think outside the object's intended use. If you need to prop open a door and you don't realize your shoe could work, that's functional fixedness in action. All right, now let's talk memory. Memory is the process of taking in information, storing it, and getting it back when you need it. And how that works? Well, psychologists have built a few models to help explain it. We'll start with the multis storere model. It's going to break memory into three stages. First, sensory memory, which is brief immediate info from the environment. It includes both iconic memory for our site and echoic memory for our hearing. If you pay attention enough, this information moves into short-term memory. But you can only hold a few items here and only for about 20 to 30 seconds or so, unless you actively rehearse the information. From there, it enters long-term memory with a potentially limitless and almost permanent capacity. Now, let's layer in the working memory model, which gives us more detail to what's happening in short-term memory. So, at the center is the central executive or your brain's manager. It directs attention and decides what info to focus on. Then you've got the two helper systems, the funological loop, which processes sound and language, and the visiatial sketchpad, which handles visual and spatial information. Together, they help you work through problems in real time, like doing math in your head while looking at a diagram. Long-term memory breaks down into two big categories, explicit and implicit. Explicit memory is stuff you consciously recall. This includes your episodic memory, which includes our personal experiences. You know, things like your prom, your first concert, and what you had for breakfast. Semantic memory is factual. Knowing the capital of France or how many legs a spider has falls under this category. Our implicit memory, on the other hand, is unconscious. It just sort of happens. Procedural memory is knowing how to do something like ride a bike, tie your shoes. You know, you're not actively thinking about each movement. It's sort of just automatic. On top of all that, there's also prospective memory, which involves remembering to do something in the future, like watching your nightly session of get psyched with yours truly, hopefully at least, right? When you form a memory, neurons fire and strengthen their connections. That process is called long-term potentiation, and it's key to how learning and memory happen on a neural level. The more you activate a pathway, the easier it becomes to access later on. Some memories just happen through automatic processing. You don't even try to remember what you had for breakfast yesterday, but it's probably there and easy to recall. Other times, it takes effortful processing like cramming definitions for this exam, which will require a bit more brain power. This leads to the levels of processing model, which says the depth of your processing affects how well you remember it. At the shallowest level, you've got structural processing and phmic processing. But if we go deeper with semantic processing, we start to encode information by focusing on its meaning. For example, if you're trying to remember the term classical conditioning, well, instead of just memorizing the definition, you could think about Pablo and his dogs, how the bell was paired with food, and how the dogs eventually salivated at just the bell. Semantic processing is the deepest level of processing in the levels of processing model and you know probably the best one to use if you want to remember things. So how do we actually get this stuff into memory? Well that process is called encoding which involves converting information into a form your brain can store. Some encoding happens automatically. But when you want to remember something on purpose there are proven techniques to help make it stick. Let's start with pneummonic devices, which are just tricks for remembering info by connecting it to something more meaningful or familiar. Roy G. Biv for the colors of the rainbow. That's a classic. Or how about the method of Losi, also referred to as a memory palace. You know, imagine walking through a familiar place like your house, and mentally placing information in each room. Then later on, when you're trying to recall stuff, you walk through that location in your mind in order to retrieve the information. Should be there waiting for you. Next up is chunking. Your brain loves breaking info into meaningful chunks. All of our phone numbers are chunked. Instead of remembering 10 random numbers, they are chunked into three separate numbers. By the way, that's not my phone number. I don't recommend calling it. Even better, group those chunks into categories or hierarchies. That structure will give your brain an even bigger retrieval boost. Now, moving on. You've probably heard the phrase, don't cram, and here's why. The spacing effect says you remember info better when you study it over time. It's a powerful tool for long-term retention. The opposite, mass practice, is when you try to cram everything into one session. You know, it might work short term, but it's not ideal for lasting learning. What you want is distributed practice, reviewing content across multiple sessions. That's how you actually lock it all in. Now, have you ever studied a list and remember the beginning and the end, but forgot what's in the middle? Well, that's a psychological theory known as the serial position effect, which is a pattern that includes two key principles. We have the primacy effect, where you're more likely to remember items from the beginning of a list. And then we have the recency effect, where you also tend to recall the most recent items you saw the middle. Tough luck. Now, memory isn't just about studying harder. It's about studying smarter. And now that we've encoded it, let's talk about storing that information so we can retrieve it later on. So storage is just a process of maintaining info in memory over time. But just because it's in there doesn't mean it's locked in there forever. The way you rehearse plays a huge role in whether something sticks. First up is maintenance rehearsal. It's just the repeat it until you remember it method, like repeating a phone number in your head until you can write it down. It works shortterm but doesn't always lead to long-term storage. Now, a better option that's going to be elaborative rehearsal, and that's just when you connect new info to stuff you already know. So, you're pretty much adding meaning, making associations, and that's what helps things move into long-term memory and actually stick there. One type of long-term storage you use every day is autobiographical memory, which includes personal memories from your life. But memory isn't perfect. So, how about we talk about amnesia? Retrograde amnesia is when you can't remember things before the event, like a head injury wiping out past memories, while intrograde amnesia means you can't form new memories after the event, bringing us back to the 51st dates reference. There's also infantile amnesia, which is the reason you can't remember being a baby. Your hippocampus and language centers just weren't developed enough yet to store those memories long term. And finally, we have Alzheimer's disease, which is a degenerative brain disorder that progressively destroys memory and cognitive function. It often starts with intrograde symptoms and gradually leads to broader retrograde memory loss as well. Bottom line, storage isn't just about keeping information. It's about how you store it, where you store it, and what happens to your brain over time. So, you've encoded the info, you've stored it, now it's time to retrieve it. Retrieval is just a process of bringing a memory back into conscious awareness. There are two main ways we do this. Recall is bringing info up without any cues like answering a free response question. No help, just brain power. Recognition is when you identify the correct info from choices, like a multiple choice question. The info's there, you just have to spot it. But here's the thing. Retrieval depends a lot on context. Ever walk into a room and forget why you're there, but then remember when you go back where you started? Well, that's context dependent memory at work. Your surroundings act as retrieval cues. Then there's state dependent memory. When your physical or mental state affects retrieval, if you learn something while tired or caffeinated, you might recall it best in the same state. And mood congruent memory, if you're feeling sad, you're more likely to recall sad memories. Happy, you'll remember the good stuff more easily. So, you don't just retrieve for the test, you retrieve to strengthen memory. That's what the retrieval practice process is all about. Every time you recall something, it reinforces the pathway, which is a good thing. The testing effect shows this in action. Quizzing yourself, actually practicing retrieval is way more effective than just rereading notes. You're not just reviewing. You're building stronger neural connections. And to top it off, there's metacognition, or thinking about your thinking. It's when you reflect on what you know, what you don't, and how you're learning. If you've ever said, "I need to spend more time on unit two." Congrats. You've just used metacognition. Now, retrieval isn't just the final step. It's part of the learning process. Now, let's wrap up memory by talking about what gets in the way of memory. Forgetting, distortion, and failure to retrieve. So, what does happen when memory doesn't work? Let's start with the classic, the forgetting curve. Psychologist Herman Ebinghoff showed that we forget most info pretty quickly, unless we actively review it, of course. So, you might remember a lot right after studying, but a few days later, gone. Unless you're using spaced practice or retrieval to slow that drop. Sometimes we never actually remembered it in the first place. That's going to be encoding failure. The info didn't make it into long-term memory, so you just don't fully remember it. So, you've probably seen hundreds of pennies, but could you actually draw one perfectly from memory? Probably not. Then there's interference theory, when old and new memories compete. Proactive interference is when old info blocks new info, like writing last year's date on your paper in January. Retroactive interference is when new info messes with old info. Like forgetting your old locker combo after learning a new one. Remember, proactive old, retroactive new. Now, there's a pneumonic there that I should probably not say out loud, so I'll just uh let you figure it out on your own. Sometimes you know it but can't get to it. That's inadequate retrieval, like the tip of the tongue phenomenon. You're so close but just can't quite recall the word. And sometimes your brain even works to protect you. Repression, a Freudian idea, states that your brain might bury traumatic memories deep in your unconscious in order to avoid distress. Now, modern research questions this, but it's still a big theory in psych history. Our memories aren't like video recordings. They're constructive. We rebuild them each time we recall them, and that means they're vulnerable to distortion. The misinformation effect shows us that exposure to misleading info after an event can alter your memory. Like, if someone says, "Did you see all that broken glass?" when referring to a car crash. Even if there wasn't any, you might remember it that way just because someone mentioned it. Then there's source amnesia. When you remember the info but forget where it came from. You might think it's something you read in a textbook, but it was actually from a movie or even a dream. This can lead to imagination inflation, part of constructive memory. You picture something vividly and start to believe it actually happened. So, as you can see, memory is powerful, but it's not perfect. Now, let's finish up unit two by talking about how we measure intelligence and where all this knowledge takes us. We'll start with intelligence. One of the most studied and debated areas in psychology. Psychologists define intelligence as the ability to learn from experience, solve problems, and adapt to new situations. Charles Spearman believed that there is a single general intelligence or G factor that underlies all of our mental abilities. So, if you're good at math, chances are you're also good at reading because they both tap into that G factor. One common way we measure intelligence is with an intelligence quotient or IQ scores. Now, originally, IQ was based on mental age or how your intellectual performance compared to average performance at a specific age range. So, if a 10-year-old performed like an average 12-year-old, their IQ would be 120. These days, IQ scores are calculated using standardized norms, but the idea of mental age helped build the foundation. Not everyone agrees with Spearman's single score idea. Robert Sternberg, for example, argued that intelligence is more complex. His triarchic theory breaks it down into three types: analytical intelligence, creative intelligence, and practical intelligence. In Sternberg's view, someone could bomb a standardized test but still be highly intelligent in ways that IQ tests don't capture. But a good test isn't just about giving you a number. It has to be valid and reliable. Validity means the test measures what it claims to measure. First, we have construct validity, which looks at if the test truly assesses the concept of intelligence. And next we have predictive validity which is going to look at if the test accurately forecasts future performance like academic success. Reliability means you get consistent results across the board. The test retake method checks if your score stays stable over time. And the split half method sees if both halves of the test yield similar results. Testing is never just about intelligence. Social factors matter too. Stereotype threat is when awareness of a negative stereotype causes someone to underperform. Like a girl taking a math test after hearing boys are better at math. It can seriously mess with her focus. On the flip side, stereotype lift is when positive stereotypes boost performance. Like being told your group excels at a task and then rising to the occasion. Across generations, IQ scores have gradually increased. That's the Flynn effect. likely due to better education, nutrition, and more access to information. But not all tests are created equal. An achievement test measures what you already know, like the AP psych exam, while an aptitude test measures your potential to learn, so things like the SAT or ACTs. Your mindset matters, too. People with a fixed mindset believe intelligence is unchangeable, so they give up when things get hard. While people with a growth mindset believe effort leads to improvement, and they tend to achieve more in the long run, the takeaway here, you're not stuck with where you are now. You can train your brain, learn more, and get better, especially when you believe you can. All right, so we've talked about memory, thinking, problem solving, and that juicy cognitive stuff, but now it's time to zoom out a little because cognition doesn't just show up one day fully formed. It develops and so do we. Developmental psychology is all about how people change and stay the same across the lifespan. From that first baby giggle to a midlife crisis all the way to elderly wisdom, it's all fair game. One of the key questions developmental psychologists ask is about stability and change. So, are our traits consistent throughout life or are they going to shift over time? We're going to see that some traits stay rock solid while others they might flip-flop a bit. Then there's the classic nature verse nurture debate we've talked oh so much about. A quick refresher. Are we who we are because of heredity and biology or our environment and experiences? As we already should know by now, it's always both. Another major question. Do we develop in continuous ways like gradually improving over time or in discontinuous stages where development is like leveling up in a video game? To explore these questions, psychologists use research methods such as cross-sectional and longitudinal studies. Cross-sectional studies are where researchers compare different age groups at the same time. So this might look like testing a group of 10 year olds, a group of 20-year-olds, and a group of 30-year-olds all on memory in order to see what the differences are. We also have longitudinal studies where they follow the same group of people over time. This would be more like tracking one group of kids every 5 years from preschool to adulthood. Both approaches give us insight into how humans grow and develop just from different angles. Now, let's talk bodies. how they develop, change, and shape who we are. Before a baby even enters the world, development is already underway. And while the womb should be the safest place, outside substances called territogens, which are things like drugs or alcohol, can interfere with development and lead to serious problems. Once born, we move into infancy where growth is wild and fast. Babies start with basic involuntary movements known as infant reflexes like the rooting and sucking reflex that help them eat. From there, we develop gross motor skills, things like crawling and walking and fine motor skills like grabbing a Cheerio or scribbling on the wall. Vision also develops early on. The classic visual clip experiment showed us that infants develop depth perception as early as crawling age. Researchers found in a safe way, of course, that most infants won't crawl over a visual drop because they sense danger. But not all development can be delayed. According to the sensitive period hypothesis, certain skills like language must be acquired within a particular window early in life or the brain might not develop them properly at all. Now, we're going to fast forward to adolescence. Hello, puberty. That's when we see changes in primary sex characteristics like reproductive organs and secondary sex characteristics like voice deepening, body hair growth and breast development. For females, puberty includes monarchy and for males spermarky. And way later in life, for many women, there's menopause when menration ends and the body undergoes hormonal shifts and reproduction is no longer possible. Now, understanding development means considering both the body and the brain, biology and identity. And this is just the beginning. Next, we'll dive into how thinking itself develops over time. So, let's talk about how we think, learn, and reason from baby brains to older minds. In our last unit, we talked about schemas, assimilation, and accommodation. Well, those processes are all central to PJ's theory of cognitive development, which breaks into four main stages. First up, the sensory motor stage. Here, babies explore the world through senses and movement. They learn object permanence, which is the understanding that things still exist even if they can't see them. Before that, hide their toys and they're gone forever. You know, out of sight, out of mind. Next up, the pre-operational stage. Language explodes, but logic not quite there. They struggle with conservation, lack reversibility, demonstrate animism, and are quite the egocentric little gremlins. Luckily, that begins to fade as they develop theory of mind, realizing other people have thoughts, feelings, and beliefs as well. Around age seven, kids enter the concrete operational stage. Here they start to understand conservation, reversibility, and logic, but only with tangible things. Abstract thinking still developing. That's going to come in the formal operational stage, usually starting around age 12. Now, they can think hypothetically, solve complex problems, and consider abstract concepts like justice or freedom. But not all learning happens on your own. According to Votssky, cognitive development is a social process. He introduced the idea of scaffolding when a more knowledgeable person like a teacher or parent supports a child's learning just enough to help them succeed gradually pulling back as the child gets more capable. This support is most effective when it is given in the zone of proximal development or the sweet spot between what a learner can do alone and what they can't do even when they have that help. As we move through adulthood, our cognitive abilities continue to shift. Crystallized intelligence or the knowledge and facts we accumulate throughout our lives tends to grow or stay stable with age. But fluid intelligence or the ability to think quickly and solve novel problems can decline over time. In some cases, those cognitive declines become more serious. Dementia is a broad term for cognitive decline that interferes with daily life, including memory loss, confusion, and difficulty communicating. So, from peekab-boo to hypothetical moral dilemmas, cognitive development is a journey, one shaped by both biological maturation and social experience. Now, let's talk language. Arguably the most powerful tool the brain ever cooked up. So, language is more than just speaking. It's the system we use to communicate, built from sounds, symbols, and rules. And what makes it especially cool is that it's generative, meaning we can use a finite number of words to create an infinite number of unique sentences. You've never said the exact sentence you're saying now, unless you're quoting yourself, of course. At the foundation of language, we've got phonms or the smallest units of sound. English has around 40 of them. Then we combine these phonms into morphems or the smallest units that carry meaning. For example, unbelievable has three more themes. Un, believe, and able. Semantics is the meaning of those words and sentences like knowing crash means different things depending on if you're talking about a computer or your car. Grammar is the whole system of rules that guides language. And within grammar, syntax is how we arrange words into sentences. You know, switch around a few words and suddenly the dog snip the man's butt becomes, well, a bit weird. Language development starts early. First comes cooing, those vowel-like sounds babies make just to explore their voice. Then babbling, when they start combining consonants and vowels like baba or da da. Next comes the one word stage where a single word might mean a whole sentence. You know, milk might mean I want milk, there's milk, or spill on aisle three. That leads to telegraphic speech, which are two-word combos like want toy or go park. It's called that because like the unnecessary words get cut out, but the meaning is still there. As kids start learning grammar rules, they often go through overgeneralization like saying run instead of ran or tooths instead of teeth. They're not wrong, they're just too consistent. Language is a core part of cognitive development and it tells us a ton about how children understand and interact with their world. Now moving on, social and emotional development is all about how we interact with the world, how we form relationships, build identity, and ride the roller coaster of growing up. Let's start with Yuri Bron Brener's ecological systems theory, which basically says development doesn't happen in a vacuum. Instead, it's a series of nested layers, like one of those creepy Russian dolls. At the center is your micro systemystem, so your immediate environment. So things like family, friends, and school. The meos system is how those parts interact, like how your parents talk to your teacher. The exosystem includes settings you don't directly participate in, but they are still going to affect you. So things like your parents' job. The macro system includes cultural values, beliefs, and laws. And the chrono system adds time, explaining how historical context and life events shape you as you grow. Now, zooming in a bit, let's talk about parenting styles. Authoritarian parents are all about strict rules and obedience. Think drill sergeant. Permissive indulgent parents want to be your best friend and let you do whatever you want, while permissive indifferent parents are hardly there to provide structure in the first place. Then we have authoritative parents or the sweet spot, firm but supportive. Research shows this style generally leads to the best outcome for kids. And then there's attachment. Secure attachment forms when caregivers are responsive and consistent. When this happens, the child feels safe exploring the world. Insecure attachment, on the other hand, is quite the opposite and comes in three forms. Avoidant, anxious, and disorganized. Attachment is also shaped by temperament, which is a baby's basic personality. You know, some are chills, some are high strong, and most land somewhere in between. You'll also see separation anxiety and securely attached toddlers. It's developmentally normal and actually a sign of a strong bond. Harry Harlo's monkey studies gave us contact comfort, or the idea that physical closeness and warmth matter even more than food when it comes to forming attachments. As kids get older, social play evolves. Parallel play is when toddlers play near each other but not really with each other. Then comes pretend play or acting out stories and using imagination. It's huge for cognitive and social growth. In adolescence, social awareness explodes. Enter the imaginary audience which is the belief that everyone is watching and judging you at all times. Pair that with a personal fable which you know no one understands me. My experience is totally unique. Teenagers are dramatic. Science agrees. Then there's the social clock, which is the cultural expectations for when you're supposed to hit life milestones such as graduating, getting a job, starting a family, etc. Missed the deadline and people can feel behind even when there's really no rush. Now, let's shift to Eric Ericson Psychosocial Stages of Development, which is a stage-based theory covering your entire life. Each stage has a conflict, and how you resolve it shapes your identity. We've got trust versus mistrust, autonomy verse shame and doubt, initiative verse guilt, industry vers inferiority, identity versus role confusion, intimacy vers isolation, generativity vers stagnation, and ego integrity verse despair. If those early stages are disrupted by trauma or instability, that's where adverse childhood experiences or aces come into play. Abuse, neglect, and household dysfunction can have long-term effects on emotional and physical health. During adolescence, identity becomes the name of the game, and James Marcia breaks it down into four identity statuses. We have achievement, diffusion, foreclosure, and moratorum. Each status reflects how young adults are figuring out who they are. A process that's messy, nonlinear, and deeply influenced by social and emotional experiences. So yeah, development shapes who we are, but not everything is about identity or emotions. Sometimes behavior is just learned. So let's talk classical conditioning. Meet Doug's friend, Lily. Lily has always loved hiking, peaceful trails, fresh air, and the occasional squirrel sighting. Well, up until the incident, of course. One sunny afternoon, Lily was walking through the woods when bam, a snake slithered out from behind a log and scared the absolute daylights out of her. In that moment, the unconditioned stimulus was the snake. It naturally triggered an unconditioned response of fear. Now, the snake appeared right after she stepped over a fallen log. And just like that, Lily's brain started forming associations, associative learning and action. After a few more hikes and a couple more logs, but no snakes, her brain still linked to log equals snake equals panic. That fallen log, it became a conditioned stimulus. And her fear response, now that's a conditioned response. Welcome to classical conditioning, my friends. This learning process is called acquisition. When the brain links the neutral stimulus of the log with the unconditioned stimulus of the snake and starts reacting to it in the same way. But here's the thing. After a while, Lily hikes a bunch of trails, steps over dozens of logs, and nothing happens. Eventually, the fear fades. That's called extinction, when the conditioned response weakens because the unconditioned stimulus stops showing up. But one day, weeks later, she's hiking again, steps over a log, and bam, her heart rate spikes. No snake, just the fear suddenly returning. That's spontaneous recovery. The conditioned response coming back out of nowhere even after extinction. Now, let's say Lily only reacts to logs that look exactly like the one from the snake encounter. That's stimulus discrimination. Learning to respond only to a specific stimulus, not ones that are similar. But if she starts freaking out at any long brown object, logs, trees, branches, garden hoses, that's stimulus generalization. Over time, Lily also starts panicking when she hears rustling leaves, even without seeing a log. That's higher order conditioning when a new neutral stimulus, which could be the sound of the leaves, becomes associated with the original condition stimulus of the log, creating a new conditioned response. Her therapist suggests counter conditioning or pairing the fear triggering stimulus of logs with something calming like her favorite music or a deep breathing exercise. And while we're at it, why not talk about food for a second? You know, I could always talk about food. Now, I want you to imagine Lily eats some sketchy gas station sushi before one of her hikes, and later on she gets sick. Not from the sushi, per se, but the 2 week old rotten salmon that was inside of it. Well, now even the thought of just sushi alone makes Lily nauseous. Well, that's taste aversion. And it often happens in just one trial. Why? Because well, humans are evolutionarily wired to make food sickness connections fast. It's called biological preparedness. We're primed to learn some associations like food plus illness more easily. And this connects to biological predispositions. Some fears like snakes or spiders are more easily conditioned due to our evolutionary past. One last thing. If Lily hikes the same trail every day, eventually the sound of rustling leaves stops bothering her. She's no longer reacting to it. That's habituation. When you stop responding to a stimulus after repeated exposure. All right, so Lily's finally over her log anxiety. Now, let's say she's back on the trail, but this time she brings her emotional support dog, Bean. Bean's adorable, but Bean's also untrained, which is unfortunate for an emotional support dog. Every time Bean stays on the path, instead of darting after squirrels, Lily gives her a treat. And that treat, well, that's positive reinforcement. Lily adding something pleasant. That pleasant thing being the treat Bean's getting in order to increase the behavior of Bean staying on the path. One day, Bean's leash gets tangled and Lily gently removes it. The leash was annoying. Taking it away makes Bean more likely to sit still next time. That's negative reinforcement. Removing something unpleasant to increase a behavior. But Bean's not perfect. She jumps up on a hiker, so Lily sprays her with some water. That's going to be positive punishment when you add something unpleasant in order to decrease a behavior from repeating itself. Later, Bean chews up her favorite toy beyond repair. So, as a result, Lily takes away her squeaky duck for the rest of the day. That's negative punishment. You remove something good in order to decrease a behavior from repeating. Now, let's talk about what motivates bean in the first place. Treats, belly rubs, well, those are all primary reinforcers. They're satisfying basic biological needs. With the sound of Lily saying, "Good girl." That's a secondary reinforcer, and it's been linked with rewards over time, but doesn't fulfill a need on its own. Whether it's hiking habits or puppy training, the basic idea stays the same. Operant conditioning is all about consequences. Reinforcement increases behavior. Punishment decreases it. And now Lily's starting to realize maybe she's not just learning about psychology. Maybe, just maybe, she's living it. Now Dean's doing great, but she still hasn't nailed the perfect sit. So Lily uses shaping, you know, reinforcing closer and closer behaviors to what she wants. So, first Bean gets a treat for stopping, then for sitting halfway, then finally that full sit puppy dog eyes staring right up at you. Each little step in the process, that's a successive approximation, which are just tiny movements toward the full behavior. But here's the thing. Lily can't give Bean a treat every single time. Why, you may ask? Well, she'd go broke and then Bean would be at an increased risk of type 2 early onset canine diabetes. So, Lily switches to a partial reinforcement schedule where Bean only gets a treat sometimes. If Lily gives a treat after a set amount of time, like every 5 minutes of good behavior, that's a fixed interval schedule. If it's after a random amount of time, like I'll reward her when I feel like it, that's going to be variable interval. Now, if Lily rewards Bean after a set number of commands, like every third sit, that's a fixed ratio schedule. But if Bean never knows which sit will get the reward, that's going to be a variable ratio schedule, and it's super resistant to extinction. But not all learning is easy. Sometimes Lily tries to teach Bean something, like to not destroy her toys, but she does it anyways, even after being given treats for not doing it in the past. That's going to be instinctive drift when an animal reverts back to one of its more instinctual behaviors. Now, let's say one day Bean was just spinning in circles and Lily came over and randomly gave her a treat. That might reinforce what might become a superstitious behavior of Beans, causing her to randomly run in circles in the future hoping for a treat again. And every time Lily gives her a treat, it might reinforce that superstitious behavior. And sometimes sometimes Bean fails again and again, like trying to jump over a fence that's too high for her. Eventually, she just gives up even after Lily lowers the fence. That's learned helplessness. When someone stops trying because past attempts didn't work, even if the situation has changed. Operant conditioning is powerful. It can shape everything from pet tricks to life outlooks. So far, Lily's learned through rewards, punishments, and straight up conditioning. But not all learning happens directly. One day, Lily watches her classmate calmly speak during a presentation and totally kill it. Next time she presents, she channels that same energy. And that's social learning theory, where we learn by watching others. No rewards or punishments necessary, just relaxation and observation. When Lily's behavior changes after seeing someone else get praised for something, that's vicarious conditioning or learning through their consequences, not your own. And that classmate she copied, that's a model, someone whose behavior you imitate. Now, let's talk about learning that happens under the radar. Like when Lily's dad drives her to school every day, she never really paid attention to the route, just zoned out to the sweet sound of Nickelback classics. But then one day her dad's sick. She hops on her bike and suddenly knows exactly how to get there. That's latent learning, which is learning that's stored away until you actually need to use it. Turns out her brain made a cognitive map or a mental layout of the route without her even realizing. And then there's insight learning. It's not trial and error. It's that light bulb moment when everything just clicks. Like when Lily's trying to hang a picture frame, she's struggling for 10 minutes, then suddenly flips the hammer around and uses the claw end to pull the nail. Boom. Insight. No modeling, no reinforcement. Just problem-solving magic. All right, so unit 3 is over, but let's keep the momentum going because I want to get over with this. I think I'm starting to lose my mind a little bit. You know what? Actually, actually, we're going to stop the momentum real quick. If you've been watching the Get Psyched channel throughout each unit review and now our Crathon Extravaganza trademarked, you already know I live my life a quarter mile at a time. And right now, that quarter mile is this video. This review, it's not just a cram session. It's about something much more important. It's about family. So, if you haven't already hit subscribe, you could. But honestly, this is kind of our final lap, isn't it? I mean, we've spent hours together across unit reviews, science practices, and now the crathon extravaganza trademarked. And after the exam, we part ways. I know, I know. It's just like Vin Diesel and Paul Walker at the end of Furious 7. It's been a long day without you, my friend. and I'll tell you all about it when I see you again. All right, and we're back. Sorry about that, by the way. Just got done with my monthly Fast and the Furious binge. Love me some Paul Walker. RIP, baby. Any who, now let's talk about how we explain people's behavior. Starting with attribution theory, which is just that, looking at how we explain someone's behavior. Sometimes we say it's because of who they are, like personality or attitude. That's going to be a dispositional attribution. And other times we credit the situation. Maybe they were having a rough day, stuck in traffic, whatever. That's going to be a situational attribution. Now, your explanatory style, whether you're an optimist or pessimist, shapes how you explain things. Optimist might blame setbacks on bad luck, while pessimists take it all personally. But our explanations are not always accurate, like the fundamental attribution error. When we overestimate dispositional factors and underestimate the situation, that guy cut you off, probably a jerk, but you cut someone off, well, you're late and stressed. It's different, right? Factor observer bias includes fundamental attribution error plus a twist. When we do something, we blame the situation. But when others do the same thing, we blame their personality. So, F AE is about others. While actor observer bias is a double standard, the classic rules for thee but not for me. And let's not forget the self-s serving bias. Success, that was all you. Failure, that was clearly someone else's fault. Then there's the locus of control, or how much control you think you have over life's events. An internal locust says, "I make my own destiny." And an external locus says, "The universe is out to get me." Now, we're going to flip the focus and take a look at how we see others. That's person perception, which is just the process of forming impressions. It's affected by everything from mood to stereotypes to how long it's been since you ate lunch. And sometimes just being around someone a lot makes you like them more. That's the mere exposure effect where repetition builds preference. But watch out for the self-fulfilling prophecy. You know, you expect someone to be annoying, treat them like they're annoying, and surprise, they act annoying. You basically created the behavior you were predicting. Now, when you compare yourself to others, that's social comparison. And it goes both ways. If you are showing upward comparison, you might think, "Ugh, they're so much better than me." With downward social comparison, you might think, "At least I'm not doing as bad as that guy." If you're always comparing and never feeling satisfied, that's relative deprivation. Feeling like you're missing out, even if you're doing just fine. And the wild part, that feeling can shape how we see others, not just ourselves. Because once we start forming judgments about people, well, let's just start with the basics. A stereotype is a belief usually oversimplified about a group. When that belief turns into a negative feeling, that's prejudice. And when that feeling becomes an action, that's discrimination. These attitudes can be explicit, meaning you're aware of them, but often they're implicit, which means you might not even realize you have them. And that's what makes implicit biases so tricky and why psychologists work to study and measure them carefully. part of the reason attitudes persist, the just world phenomenon, which is the belief that people get what they deserve. It's comforting until it leads us to blame victims instead of systems. Then there's group identity. We all belong to in-roups or groups we identify with and we tend to view them more favorably. That's going to be inroup bias. People outside those groups, that's the outroup. And we often assume they're all the same, which is going to be something called the outgroup homogenity bias. At its extreme, this becomes ethnosentrism, believing your culture is superior to others. Once we form these attitudes, we tend to protect them hard, which is not a healthy perception to have. Belief perseverance keeps us holding on even when we see contradictory evidence. And confirmation bias, that's when we look for info that proves us right and ignore the rest. Let's say the world hits us with something that totally challenges our beliefs. That internal discomfort you feel, that's cognitive dissonance. You believe one thing but act another way and your brain does not like it. So you got two choices. Change your behavior or adjust your beliefs so they line up again. And that's how attitudes can shift sometimes. All right. So you've got your thoughts, your attitudes, your biases. But none of that happens in a vacuum. Welcome to the chaos of real life, the psychology of social situations. First up, social norms. These are the unspoken rules of behavior. Don't stand backwards in an elevator. Don't sing at full volume in a library. Unless it's after finals week, I guess, then maybe we let it slide. Now, social influence theory explains how the presence of others affects us. And there are going to be two big types. Normative social influence is when you conform to fit in, like laughing at a joke you didn't even understand just so you're not feeling like the weird one out. And informational influence is when you look to others for guidance, like pretending to know where to go on a field trip, but secretly following the kid who looks confident. Then there's persuasion, which is just the art of changing someone's attitude or behavior. And it can happen throughout different routes. The central route of persuasion uses logic and strong arguments. Think of a wellressearched TED talk. While the peripheral route to persuasion relies on surface level cues, good looks, a catchy jingle, a logo that's sweet looking. And that's also where the halo effect comes in. The halo effect is when we assume someone has great traits overall just because they're attractive or charming. Basically, you know, she's a looker, so she must be smart, which it's not always the case. You know, can't have it all like myself. Then there's the foot in the door technique. You know, start with a small request and ask for more later on. Can I borrow a pencil suddenly becomes can I copy your entire homework assignment? Or you can go with the door in the face technique where you ask for something outrageous at first, get rejected, then slide in your real request. So, you know, can I borrow $100 turns into okay, well, how about 10? Conformity happens when you change your behavior to match a group. like saying you loved that confusing movie because everyone else clapped at the end. Obedience is when you follow an authority figure, like listening to your teacher, coach, or in some cases an evil scientist. Shout out Mgrim. But your culture shapes this, too. Individualistic cultures like the US emphasize independence and self-exression, while collectivistic cultures like Japan focus more on group harmony and family ties. And multiculturalism encourages respecting diverse backgrounds and identities within the same society. Now, put people in groups and things get real weird. Group polarization is when your opinions become more extreme after discussing them with like-minded people. A group of mildly annoyed students turns into a full-on mutiny over a pop quiz. Don't get any ideas, by the way. Group think is when everyone agrees, even if it's a bad idea, just to avoid conflict. Kind of like unanimously deciding to pull an allnighter, even though everyone's silently dying inside. Diffusion of responsibility is when people assume someone else will take action. That's how you end up with 20 people watching a spill in the hallway and nobody grabbing paper towels to help clean it up. Social loafing is when people put in less effort when working in groups. A classic group project move. De-individuation is when you lose your sense of self in a crowd and act in ways you normally wouldn't, like chanting at a game or going full gremlin at a concert. You know, behaviors you probably wouldn't do if all eyes were on you. Sometimes others help us shine. Social facilitation is when you perform better at easy tasks in front of others, but if it's hard, yeah, pressure makes diamonds or train wrecks. Either way, not good. We also assume people agree with us more than they actually do, bringing us to the false consensus effect. But there are ways to build unity. Superordinate goals are shaped goals that require cooperation. Think group scavenger hunts or escaping an escape room before the timer hits zero. Avoid social traps, though. those situations where individual gain hurts the group long term like everyone using all the review snacks on day one leaving nothing for Friday's 80 question cahoot or booket I'm actually a blicket guy now sorry cahoot anyways this is where I psychologists come in or industrial organizational psychologist these guys study workplace behavior productivity and how to avoid burnout or that exhausted crispy state of I literally can't anymore best example of burnout is me trying to make all of these videos before test day. If you notice less edits, it's probably because of that. This has been a marathon and a sprint combined into one. So, I hope you all appreciate all of my hard work and sacrifice because I am slowly losing my mind, I think. Plus, could have added like a solid 30 wins to my Fortnite record by now. All right, let's get back on track. So, sometimes people do just help others, and that's going to be something called altruism. No strings attached, just being a decent human. Now, you may think me making these videos for you guys is rather altruistic, but it's not. I'm actually doing it for the YouTube fame, and really, that's my only drive. But why help? The social reciprocity norm says we feel obligated to return favors. You help me move a couch, now I guess I'm helping you move your entire apartment. But one of the dark sides of social psychology, the bystander effect. So, the more people around, the less likely anyone is to help. Why? Well, situational factors like unclear emergencies, attentional factors like everyone's distracted, and again, the diffusion of responsibility. So, yeah, social situations, they bring out the best and worst in us. And they show how powerful context, culture, and company really are. But beneath all that social influence, who are you really? That brings us to something deeper, something more personal, like personality. Let's start with the psychonamic theory. This is Freud's domain where behavior is shaped by unconscious forces that we're not even aware of. According to Freud, your personality is made up of different parts battling it out. Your basic urges called the id. Your moral compass called the super ego and your ego who is the mediator trying to keep the peace and make reasonable decisions. Think of a movie or TV show where a character has the little devil and angel pop up on their shoulders. That's Freudian theory. When life gets stressful, the ego uses defense mechanisms to protect you from anxiety. These kick in automatically, and we all use them whether we'd like to admit it or not. The major defense mechanisms we need to be aware of for the AP psychology test is going to be denial, displacement, projection, regression, repression, and sublimation. Now, Freud also believed in different levels of awareness. So, some stuff is conscious, some is buried deep in the unconscious, and some is hanging out in the preconcious right below the surface, but still accessible. To get at that unconscious material, Freud and his followers used projective personality tests like the Rorshack Inklot test or the TAT. You're shown an ambiguous image and asked what you see. Your response is supposed to reveal hidden inner thoughts. Now, let's flip the script and talk humanistic theory. This approach is way more optimistic. Instead of focusing on unconscious conflict, it's about growth and potential. Carl Rogers believed people have a self-actualizing tendency and inner drive to become the best version of themselves. But to do that, we need support, specifically unconditional positive regard or being accepted and loved no matter what. So where Freud saw internal struggle and anxiety, the humanist saw self-growth, fulfillment, and being real with yourself. different approaches, same goal, understanding what drives behavior. So whether you're driving into the depths of your unconscious or climbing the ladder of self-actualization, personality is complicated stuff. But wait, we're not done just yet because not everyone agrees with Freud or even the humanists. So how about we talk about some more modern takes? Starting with the social cognitive theory. This theory says personality is shaped by how we think and how we interact with our environment. Albert Bandura was big here and his idea of reciprocal determinism explains it best. You influence your environment and your environment influences you. It's a two-way street. Your self-concept or how you think about yourself also plays a major role in personality development. If you believe in your abilities, that's self-efficacy. If you feel good about yourself overall, that's self-esteem. It's a blend of thought, action, and environment shaping who you are. Now, over to trait theories, which take a different approach. They don't care so much as to why you are the way you are, just how you are. A trait is a stable characteristic, something you consistently show across situations. The most popular model, the big five theory. Psychologists say you can describe most personalities using five broad dimensions. We have openness, conscientiousness, extraversion, agreeableness, and emotional stability, which is also referred to as neuroticism. A good acronym for remembering these traits is ocean. To measure these traits, psychologists use personality inventories, which are structured and standardized questionnaires that ask about behaviors and preferences. And behind the scenes, they use factor analysis, which is a statistical method that identifies which traits tend to go together. So whether you believe personality is built from experience or baked in from birth, there's a theory ready to explain it. And now, let's see what motivates all that behavior in the first place. Why do we do what we do? Let's break down motivation, which is the internal process that directs, sustains, and energizes behavior. One of the oldest ideas is drive reduction theory. It says we're driven by biological needs like food or water, and we're motivated to reduce those drives to return to a state of homeostasis or balance. You're hungry, you eat, you chill. But that doesn't explain why people go skydiving for fun. And that's where the arousal theory comes in. According to this one, we seek an optimal level of excitement or alertness. Too little stimulation, you're bored. Too much, you're overwhelmed. The York's Dodson law takes it a step further. Your performance is best at a moderate level of arousal. Not too chill, not too stressed, just right, just like the three bears, right? Then there's self-determination theory, which says motivation is fueled by three basic needs. Autonomy or having control. competence which is feeling capable and relatedness or feeling connected. When those are satisfied, you thrive. From here, we split motivation into two types. Intrinsic motivation is doing something because you enjoy it, like playing the guitar for fun, while exttrinsic motivation is doing something for an external reward, like practicing guitar because you know you're going to get paid to perform. Incentive theory says we're also pulled by external rewards. So things like grades, money, or praise rather than just internal needs. And don't forget about instincts. Those innate fixed patterns of behavior that show up in every member of a species, humans. We're not as instinct driven as other animals, but we still have built-in tendencies. Now, what happens when multiple motives clash? Enter Leuen's motivational conflict theory. The approach approach conflict is when you have to choose between two good things. So this could be like having to decide between your top two colleges. The avoidance avoidance conflict is choosing between two bad options like having to decide whether you want to start with your homework or your chores. And the approach avoidance conflict is when one thing has both pros and cons like asking your crush out but risking rejection. Then we've got the sensation seeking theory. Some people just crave more stimulation. They thrive on experience seeking such as trying new things, maybe thriller adventure seeking like playing extreme sports. Some have disinhibition which is being a wild party animal. And boredom susceptibility when we hate repetition because biology always finds a way back in. Let's talk about hunger. Grein is your hunger hormone. It says, "Hey, let's eat." While leptin says, "Nah, we're full." The pituitary gland helps regulate these signals and satiety is the satisfied feeling that tells you to stop eating. So yeah, whether it's hunger pushing you to the fridge or a burning need to prove your cousin wrong in a Mario Kart showdown, motivation explains the why behind our behavior. But once you're doing the thing, how do you feel about it? That's where emotion comes in. Emotion or a effect is a complex psychological process that goes beyond thoughts and behaviors. It reflects both internal and external factors, your biology, your thoughts, your culture, all combining into that roller coaster of human experience. Researchers have long debated how emotions work. Does your body react first and then your brain labels it? Do they happen together? Does your face tell your brain what to feel? The facial feedback hypothesis actually suggests that your facial expressions can influence the emotions you feel, though the evidence is a bit mixed. Still, emotions play a huge role in how we engage with the world. According to the broaden and build theory, positive emotions can expand your awareness and encourage creative thinking, while negative emotions tend to narrow your focus and limit your actions. And while basic emotions like happiness, sadness, fear, anger, surprise, and disgust might be universally recognized, display rules and elicitors, the things that trigger and regulate emotional expression, can differ widely across cultures, ages, and genders. So, we've explored what drives us, how we feel, and even how we express those emotions. But what happens when thoughts, feelings, and behaviors start to interfere with daily life? When motivation disappears, emotions spiral, and things don't feel right. That's where psychological and physical health comes into play. So, unit five, our last unit, thank you, takes us into the real world application of psychology, understanding disorders, treatments, and the connection between mind and body. So, buckle up because this last stretch, it's heavy, but it's also some of the most important stuff in the course. Now, we're entering a branch of psychology that lives at the intersection of your mind and body. Welcome to health psychology. This area studies how our thoughts, behaviors, and emotions impact physical health and vice versa. And one of the biggest connections between mind and body, stress. And not just the ug homework kind, but all types of stress. Health psychologists look at how stress contributes to real medical conditions like hypertension, which is just a fancy term for high blood pressure. And while stress gets a bad rap, it's not always harmful. There's ustress, a positive, motivating kind of stress, like feeling a little nervous before a presentation that makes you prepare harder. Then there's distress, the kind that overwhelms and wears you down. That's the one linked to anxiety, burnout, and health problems. We also experience traumatic stress after serious events like natural disasters or abuse. And even smaller things like daily hassles, traffic, tech glitches, that group chat with 97 unread messages can add up over time. And for some people, especially those with a history of adverse childhood experiences, even mild stressors can have a bigger impact. Their nervous systems are already on high alert from earlier trauma. So, how does the body actually respond to stress? Enter the general adaptation syndrome, a model showing how we physically react to ongoing stress. First is the alarm reaction. Your body goes, "Whoa!" Heart rate spikes, adrenaline pumps, fight or flight kicks in. Then there's a resistance phase. You push through, maybe even feel like you're handling it. But if the stress doesn't stop, you hit the exhaustion phase, and that's when your body starts breaking down. Immune system weakens, burnout sets in. And while the classic stress response is often described as fight or flight, there's also the tend and befriend theory, especially seen in women who may respond to stress by nurturing others and strengthening social bonds. When it comes to coping, there are different strategies. Problem focused coping means you're tackling the issue headon, like studying harder after failing a test. Emotion focused coping is about regulating your feelings instead of venting to a friend, journaling, or watching four hours of dog rescue videos on YouTube. They do get me in the fields every time, though. O different strategies work for different situations, and that's the core of health psychology. How we think and feel can affect our bodies, and how we treat our bodies can reshape how we think and feel. So far, we've spent a lot of time talking about what can go wrong with the mind. But psychology isn't just about disorders and distress. It's also about what helps people thrive. And that's where positive psychology comes in. This perspective doesn't ignore life's challenges. But it emphasizes how people find meaning, grow, and live fulfilling lives despite those challenges. Instead of only asking what's broken, positive psychologists ask what's working. They study positive subjective experiences, the internal stuff like joy, gratitude, awe, and hope. These are the feelings that contribute to subjective well-being or our personal sense of life satisfaction regardless of what's happening around us. Then there are positive objective experiences which are the observable parts of a good life. things like strong relationships, fulfilling work, and contributing to your community. At the heart of positive psychology is the idea that we all have signature strengths. Qualities such as wisdom, courage, humanity, justice, temperance, and transcendence. When we tap into these strengths, we tend to feel happier, perform better, and handle stress more effectively. And here's something powerful. Sometimes the toughest moments lead to the most growth. That's called post-traumatic growth. It's when someone goes through something painful like loss, trauma, or major life change and comes out stronger with new meaning or a deeper appreciation for life. So yeah, positive psychology isn't about toxic positivity or pretending everything's fine. It's about building resilience, cultivating gratitude, and understanding what makes life worth living. Now, while positive psychology shines a light on what helps people thrive, we also need to understand what happens when things go wrong. Because sometimes the mind can break down. Thoughts become disorganized, emotions spiral, and behavior no longer serves us. And when that happens, psychologists don't just guess, they assess, they diagnose, and they work to understand the full picture. So, let's shift gears yet again and talk about how we define, explain, and classify psychological disorders. So, when exactly is something considered a psychological disorder? Well, it's not always crystal clear, but there are a few big criteria. First, there's level of dysfunction. Is the person's thinking or behavior seriously interfering with their ability to function or not? Next, the perception of distress. So, are they experiencing emotional pain or discomfort because of the behavior? And finally, deviation from the social norm. Are their behaviors or thoughts considered far outside what's expected in their culture or community? So, cultural context matters. Just because something is different doesn't mean it's disordered. Now, diagnosing a psychological disorder isn't as simple as checking off a few boxes. It requires specialized training and evidence-based tools. In the US, professionals often use the Diagnostic and Statistical Manual of Mental Disorders or the DSM, which is published by the American Psychiatric Association. Globally, the International Classification of Mental Disorders or ICD from the World Health Organization is also widely used. Both of these are constantly updated to reflect new research and best practices. And here's something really important. Labels can help, but they can also hurt. A diagnosis can provide clarity, support, and access to treatment. But it can also carry stigma, bias, and even discrimination, especially across lines of race, gender, age, or socioeconomic background. We are going to see that many psychologists use an eclectic approach in therapy where they draw from multiple perspectives to understand and treat disorders. Here's quick breakdown of those perspectives. The behavioral perspective sees mental disorders as the result of maladaptive learned behaviors or associations. The psychonamic perspective focuses on unconscious conflicts, usually rooted in early childhood experiences. The humanistic perspective points to things like a lack of social support or a failure to achieve one's full potential. The cognitive perspective emphasizes distorted thinking patterns, beliefs, and emotional reasoning. The evolutionary perspective looks at behaviors that may have once been adaptive but now interfere with survival or functioning. The socioultural perspective highlights how issues like poverty, discrimination, or cultural norms impact mental health. And the biological perspective looks at genetics, brain chemistry, and structure as key causes of psychological disorders. Many professionals bring these all together with the biocsychosocial model, which says mental health issues usually involve a mix of biological, psychological, and social factors. And finally, there's the diathesis stress model, which says some people have a predisposition or dethesis for a disorder, but it only emerges when combined with significant stress. So, yeah, mental illness is complex. There's no single cause and no oneizefits-all explanation. That's why a good psychologist doesn't just ask what's wrong with you. They ask what happened to you and what strengths can we build on from here. So, how about now we take a look at some categories and specific disorders starting with neurodedevelopmental disorders. These disorders show up early in life and affect how someone grows, learns, or behaves. First, we have ADHD or attention deficit hyperactivity disorder. Usually, this includes symptoms like inattention, impulsivity, and hyperactivity that aren't typical for the person's age. Then there's autism spectrum disorder or ASD, which can include challenges with things such as communication or social interaction. The causes for these neurodedevelopmental disorders, well, they're still being studied, but they can include things such as genetic, physiological, or environmental factors. Next up, schizophrenic spectrum disorders. These involve a wide range of symptoms that mess with perception, thinking, and behavior. Delusions are false beliefs like thinking that the government is spying on you or that you're secretly royalty. Hallucinations are going to be fake sensory experiences like hearing voices that aren't there. Then there's also the disorganized thinking and disorganized speech. Some also experience disorganized motor behavior including extreme movement or none at all. This is called catatonia. Catatonic stuper is the total freeze up while excitement is the opposite. Lots of aimless movement. And catatonic stuper is actually considered a negative symptom of schizophrenia with another negative symptom being flat effect which is a lack of emotional expression. Now what causes schizophrenia? Well, the dopamine hypothesis suggests an imbalance of this neurotransmitter could be a contributing factor. Research also supports the idea that prenatal virus exposure or genetics can also play a role. Now, let's talk depressive disorders. We're looking at major depressive disorder and persistent depressive disorder here. Both being marked by sad or irritable mood and changes in energy, sleep, appetite, and cognition. The causes, they could be biological, genetic, social, cultural, behavioral, or even cognitive in nature. Bipolar disorders come next. They're defined by episodes of depression mixed with periods of mania, which is an intense euphoric or irritable mood with lots of energy and risky behavior. Bipolar one involves full manic episodes, while bipolar 2 involves less intense hypermanic episodes. Bipolar cycling is just a back and forth between depression and mania. Again, causes span the biological, genetic, cognitive, social, and cultural domains. Anxiety disorders are up now. These involve excessive fear or anxiety that disrupts daily life. There specific phobias like acryphobia or arachnophobia. Agorophobia is the fear of public or open spaces. Panic disorder features unexpected panic attacks which are intense bursts of fear. In some cultures, this can look like an attack day nervios. Social anxiety disorder is the fear of being judged. Taiin kioshu is a cultural specific form seen in Japan which is a general fear of offending others with your appearance or presence. And finally, generalized anxiety disorder or GAD is chronic non-specific worry that doesn't go away. Anxiety disorders may be caused by learned behaviors, maladaptive thinking, or biological and genetic factors. Now, let's talk obsessivecompulsive and related disorders. These feature obsessions or intrusive thoughts like did I lock the door and compulsions which are things like repetitive behaviors like checking the door 15 times. Among OCD this category also includes hoarding disorder and again causes can be learned cognitive or biological. Next we have dissociative disorders when someone experiences a disconnection from their memory identity or consciousness. There's dissociative amnesia where you forget key points in personal information sometimes with fugue meaning you travel or wander with no memory of how you got there. Then there is dissociative identity disorder or did formerly known as a multiple personality disorder which is going to be the presence of two or more unique personalities. These are typically linked to trauma or stress. And speaking of trauma, let's move into trauma and stressor related disorders. The big one here is PTSD or post-traumatic stress disorder. It often involves symptoms of hypervigilance, some emotional detachment, flashbacks, insomnia, and intense anxiety after experiencing or witnessing trauma. Next up, we have feeding and eating disorders. Anorexia nervosa involves intense food restriction and fear of gaining weight. Bulimia nervosa, on the other hand, includes cycles of binging and purging. Both are linked to biological genetics, social, cultural, behavioral or cognitive factors. Last up, we have personality disorders, which are enduring patterns of behavior that deviate from cultural norms and cause distress or dysfunction. They're going to be divided into three clusters. Cluster A is the odd and eccentric cluster containing paranoid, schizoid, and schizotypal personality disorders. Cluster B is the dramatic and emotional cluster. Here we have antisocial, hyeronic, narcissistic and borderline personality disorders. And cluster C is the anxious and fearful cluster which includes avoidant, dependent and obsessive compulsive personality disorder. And just like the others, causes can come from multiple perspectives, biological, genetic, social, cultural, behavioral, and even cognitive. Phew, lot of disorders. But remember, these labels help us understand, support, and treat people, not define them. So, let's be sure to act as a humanist and keep that empathy in the mix. So, we've talked about what psychological disorders are, but how do we treat them? Well, let's start with the good news. Psychotherapies are generally effective. Meta analyses show that many people improve with treatment, especially when therapists use evidence-based interventions, which are just strategies backed by solid research. But success isn't just about the method. It's also about the relationship. Therapists are expected to demonstrate cultural humility and form a therapeutic alliance with clients. That's the trust, respect, and understanding that help therapy work. Now, historically, there was a major shift in how treatment was delivered thanks to better psychotropic medications. Many people no longer needed long-term hospitalization. This led to deinstitutionalization, moving away from asylums and toward community- based care. Today, most treatment plans combine medication with some form of talk therapy matching the client's needs. And let's not forget psychologists are bound by ethical principles like non-maleficence or doing no harm, fidelity or being trustworthy, integrity and respect for human dignity. So how about now we run through the major therapy types. Psychonamic therapy digs into the unconscious. It uses tools like free association and dream interpretation to uncover hidden conflicts often rooted in childhood. Cognitive therapy targets distorted thinking using tools like cognitive restructuring. Clients challenge negative beliefs often tied to the cognitive triad. Fear hierarchies are sometimes used gradually working up to anxiety triggers. Applied behavior analysis applies learning principles to change behavior. This includes exposure therapy like systematic desensitation, aversion therapy, and token economies. BOF feedback is another behavioral tool. It helps clients control body functions like heart rate or muscle tension, often linked to anxiety or stress. Cognitive behavioral therapy or CBT blends the best of both cognitive and behavioral approaches. Varants like rational emotive behavior therapy or RBT and dialectical behavior therapy called DBT are especially helpful for treating mood and personality disorders. Humanistic therapy, especially person- centered therapy, is all about the individual's potential. It uses active listening and offers unconditional positive regard to help clients feel safe, accepted, and understood. And of course, group therapy exists, too. It provides support in a social setting and is often more affordable. It's not just individual therapy time six. It has unique benefits like shared experiences and learning from others. Now, what about less common tools? Hypnosis can help manage pain and anxiety, but research doesn't necessarily support its use for things like memory recovery. From a biological perspective, we've got a range of psychoactive medications. Anti-depressants target mood disorders. Anti-anxiety drugs help calm the nervous system. Lithium helps regulate mood and bipolar disorder. And anti-csychotics help manage schizophrenia and other disorders. But watch out for side effects like start of diskynesia, which is a movement disorder tied to not enough dopamine. There are also more invasive methods like actual brain surgery. And then you've got something called electrocombulsive shock therapy where they attach electrodes to your brain and actually zap you into a seizure attempting to reset it in order to help with things like treatment resistant depression. And then you've got transcranial magnetic stimulation or TMS, which uses magnetic pulses to help stimulate the brain in order to deal with the symptoms of some disorders that aren't responding to medication. And yes, there's the infamous labbotomy, a historical and now obsolete practice that taught us a lot about the importance of ethical care. Great moments are born from great opportunity. And that's what you have here today, friends. That's what you've earned here today. One test. If we took it 10 times, maybe we'd get a two on nine of them. But not this test. Not today. Today, we show the College Board. Today we stay with them in their big test because we can. Today we are the smartest AP psych students in the world. You were born to be AP psych students. Every one of you and you were meant to be here. This is your time. Their time. Their time is done. It's over. I'm sick and tired of hearing how hard this test might be. Forget it. This is your time. Now go out there and take it.