Developmental Psychology: The Younger Years

Definitions and Scope

Developmental Psychology: Study of physical, cognitive, and social changes throughout the lifespan.
- Physical: Basic body development affecting behavior.
- Cognitive: Thinking, feeling, internal activities.
- Social: Interactions with others.
Lifespan Development: Refers to the study from conception to old age.
Time: Key element in developmental psychology, studied over years.

Due to the vast number of articles and information, specialization in specific areas (e.g., educational development, morality) is necessary.
Example question: Vocabulary comprehension across cultures is not a lifespan psychology experiment (no aspect of time involved).

Traditional view: One sperm + one egg = individual.
Chimera: Individual created from multiple sperms and/or eggs.
- One fertilized egg fusing with another (fertilized or unfertilized) egg can create chimeras.
- Genetic tests revealing different DNA in various body parts indicate chimerism.
- Difficulty in determining base rate due to the need for extensive genetic testing across all body parts.
Estimated chimerism rate: Low (around 1-2%); could impact behavioral genetics if rate high.

Stages:
- Germinal Period (0-2 weeks): Chimeric opportunities primarily within this period.
- Embryonic Period (3-8 weeks): Development of organs (organogenesis).
- Fetal Period (9-38 weeks): Major brain development.
Substance Exposure:
- Greatest impact on development if exposure occurs during the initiation of specific organ development.
- Examples: Nicotine, caffeine, alcohol, leads to birth defects like fetal alcohol syndrome.
Synaptic Connections: Excess at birth for adaptability—connections later pruned based on use (e.g., language development).

Neuroplasticity: Greater early in life; ability for the brain to rewire and repair.
- Highest at birth, declines around puberty, stabilizes in adulthood.
- Critical for early milestone developments (e.g., language, socialization).
Importance: Missing early development can lead to lifelong deficits.

Survival Reflexes: Essential for newborn survival (e.g., breathing, sucking, swallowing).
Primitive Reflexes: Evolutionary holdovers, usually disappear by age two (e.g., Moro reflex, grasping).
Reflexes monitored by physicians for neurological health.

Initial Preferences: Faces (human-like), mother’s voice, mother’s smell, and taste.
Language Development: Mean estimates for language milestones: 1 year (one word), 2 years (two words), 3 years (three or more words). Plus/minus six months variability.
- Delays often related to hearing issues.

Habituation: Decreased response to repeated stimuli; used to study infant cognition and memory.
Experiments: Subject exposed to stimulus repeatedly until response declines, then presented with a new stimulus to measure recognition and memory.
Applications: Study visual acuity, memory retention, discrimination of shapes and sounds.

Understanding early cognitive and physical development is crucial for identifying potential developmental issues early and providing timely interventions.
Critical Periods: Early intervention during periods of high neuroplasticity can mitigate long-term deficits.

Which stage is most important for psychological processes?

Which reflexes are likely evaluated by physicians for an 18-year-old?