foreign this is a population pyramid a population pyramid is a graph that shows the age and sex of people that live in a particular place whether it's a City Country continent planet or anything in between you'll notice that a population pyramid is really just two bar graphs that form this shape that kind of looks like a pyramid personally I would have called it a population Dorito or maybe a population Toblerone anyway the bar graph on the left represents the male population and the bar graph on the right represents the female population each bar graph uses this y-axis in the middle that shows the ages of the population in increments of five years the x-axis shows what percentage of the population each bar represents for example we can see that males aged 0-4 make up nine percent of this total population now that we can read a population pyramid let's talk about the different categories of population pyramids there are three of them and they are expansive stationary and constrictive the first type is an expansive population pyramid this one shows the population of Chad a country in Africa that word expansive in this case means the population is expanding or growing and this is because each new generation is bigger than the one before it for this reason expansive populations have large young populations you can see that nearly half of Chad's population is under 15 years old one reason for this is high birth rates which means women are having more babies and at younger ages this is good for the population growth but it's not that good for women because having babies at a young age can mean missing out on education and employment the other main reason for the large young population is that expansive populations have shorter life expectancies this population pyramid shows that only a small amount of Chad's population live past 65 because of poverty related problems like not enough food water and health care that's why it's typically developing countries like countries in Africa parts of Asia and South America that have expansive populations the next category is stationary population pyramids and this is for places where the people are pencils and rulers and scissors but really stationary in this case means the population is stable or not growing that much we can see in this population pyramid for the United States that most of the population is pretty similar across most age groups the young population is typically smaller because women in these societies have better access to education and employment and are therefore choosing to have fewer children and choosing to have them when they're older the life expectancies are longer too because most have access to things like food water and Healthcare also you've probably noticed that it's not really a pyramid anymore it's more like a population bees butt third type of population pyramid is constrictive population pyramids take a look at this population pyramid for Italy for example it's like the population is constricted at the bottom meaning there's much lower birth rates than they used to be and we can see that the majority of the population is much older the reason the population is like this is because they have all those things that make people live longer and have less children such as very good access to Food Water Healthcare education and employment also it definitely doesn't look like a pyramid anymore it's more like a population soft serve there can also be some other weird kind of shapes for example look at these population pyramids for Qatar and Saudi Arabia it looks more like a population woodpecker this is because they had a whole bunch of immigrant workers typically men come to work in the booming oil and gas Industries plenty of single men if anyone's interested [Music] thank you [Music]