Stages of Human Development to Know for AP Psychology (2025) (copy)

1. What You Need to Know

Human development in AP Psychology is about how people change physically, cognitively, and socially from conception to death. On the exam, you’re usually asked to:

• Identify which stage someone is in (prenatal, infancy, adolescence, etc.).

• Match a behavior to a stage theory (Piaget, Erikson, Kohlberg, Freud).

• Interpret classic research (Ainsworth, Harlow, Lorenz) and apply it to a vignette.

The “stages” you must know best are:

• Prenatal development (germinal, embryonic, fetal) + teratogens

• Attachment (Bowlby/Ainsworth) + parenting styles (Baumrind)

• Piaget’s cognitive stages

• Erikson’s psychosocial stages

• Kohlberg’s moral development levels

• Freud’s psychosexual stages (often tested via quick identification)

• Adolescence (puberty + identity)

• Adulthood and aging (fluid vs crystallized intelligence, dementia basics)

• Death and dying (Kübler-Ross—sometimes appears)

2. Step-by-Step Breakdown

How to crush “Which stage/theory is this?” vignettes

1. Anchor the age first (rough ranges):

   • Prenatal to birth

   • Infancy: birth to about 2

   • Early childhood: about 2 to 6

   • Middle childhood: about 6 to puberty

   • Adolescence: puberty to late teens

   • Emerging/young adulthood: about 18 to 30

   • Middle adulthood: about 40s to 60s

   • Late adulthood: 60s and up

2. Match the domain clue (what kind of change is described?):

   • Thinking/logic errors → usually Piaget

   • Identity/relationships/work → usually Erikson

   • Right vs wrong reasoning → usually Kohlberg

   • Focus on pleasure/erogenous zones → usually Freud

   • Clinging/caregiver reactions → attachment (Ainsworth/Bowlby)

3. Look for the signature “tells”:

   • Object permanence problems → Piaget sensorimotor

   • Conservation errors (liquid, number, mass) → Piaget preoperational

   • Abstract/hypothetical reasoning → Piaget formal operational

   • Stranger anxiety and caregiver as “secure base” → secure attachment

   • Identity exploration (“Who am I?”) → Erikson identity vs role confusion

   • Morality based on punishment/obedience → Kohlberg preconventional

4. If it’s prenatal, decide which stage using the key biological event:

   • Germinal: conception to implantation

   • Embryonic: organs begin forming (highest vulnerability)

   • Fetal: growth and finishing touches; viability increases

Mini worked identification examples

• A 4-year-old thinks a tall thin glass has “more” juice than a short wide one: Piaget preoperational (centration; lack of conservation).

• A teen tries different friend groups and values to figure out their future: Erikson identity vs role confusion.

• A child says stealing is wrong because “you’ll get in trouble”: Kohlberg preconventional.

3. Key Formulas, Rules & Facts

A. Prenatal development (high-yield)

Teratogens = harmful agents (alcohol, nicotine, certain drugs, infections, radiation) that can cross placenta and affect development.

• Fetal Alcohol Spectrum Disorders: classic finding is lifelong cognitive/behavioral impacts; physical features can occur.

• Prenatal risk is influenced by timing, dose, and genetic vulnerability.

B. Physical development basics

C. Attachment (Bowlby + Ainsworth)

Attachment = strong emotional bond with caregivers; supports exploration and emotion regulation.

Strange Situation attachment patterns (know the behaviors):

D. Parenting styles (Baumrind)

Think demandingness (control) vs responsiveness (warmth).

E. Piaget’s cognitive development stages (must know)

Key vocabulary:

• Conservation: quantity remains the same despite shape changes.

• Egocentrism: difficulty seeing others’ perspectives.

• Theory of mind (often paired with Piaget but not his stage): understanding that others have mental states different from yours; typically develops in early childhood.

F. Erikson’s psychosocial stages (high-yield conflicts)

Erikson = social tasks across lifespan; each stage is a crisis with a healthy resolution.

G. Kohlberg’s moral development (levels + logic)

Kohlberg focuses on moral reasoning (not just behavior).

High-yield notes:

• Many people do not consistently reach postconventional reasoning.

• Vignettes often test whether the reasoning is punishment, approval, law, or principles.

H. Freud’s psychosexual stages (commonly tested as quick IDs)

Freud = personality development via conflict around erogenous zones.

I. Aging and cognition (late-life basics)

J. Death and dying (sometimes tested)

Kübler-Ross: denial, anger, bargaining, depression, acceptance.

• Not always linear; not everyone experiences all stages.

4. Examples & Applications

Example 1: Piaget (conservation vs centration)

Prompt: A child insists there are more coins after you spread them out in a longer line.

• Best match: Preoperational (centration on length; lacks conservation).

• Trap: If the child explains that spacing doesn’t change number, that’s concrete operational.

Example 2: Attachment pattern (Strange Situation)

Prompt: In the lab, a toddler clings intensely, panics when the caregiver leaves, then on return both seeks contact and angrily resists soothing.

• Best match: Anxious/ambivalent (resistant).

• Key insight: Mixed reunion behavior signals insecurity + inconsistency.

Example 3: Erikson across lifespan

Prompt: A 45-year-old mentors younger employees and volunteers weekly, feeling energized by contributing.

• Best match: Generativity vs stagnation.

• Exam twist: If the vignette is about reviewing life with satisfaction in old age, that’s integrity vs despair.

Example 4: Kohlberg reasoning vs behavior

Prompt: Someone returns a lost wallet because “I want people to think I’m honest.”

• Best match: Conventional (social approval).

• Key insight: Kohlberg scores the reason, not the action.

5. Common Mistakes & Traps

1. Mixing up Piaget stage ages and signature tasks

   • Wrong: Saying a 4-year-old failing conservation is “concrete operational.”

   • Fix: Conservation failure points to preoperational; success points to concrete operational.

2. Confusing object permanence with conservation

   • Wrong: Treating them as the same skill.

   • Fix: Object permanence = “objects exist when unseen” (sensorimotor). Conservation = “quantity stays same despite appearance” (concrete operational).

3. Assuming postconventional morality is ‘better behavior’

   • Wrong: “They did a good deed, so it’s postconventional.”

   • Fix: Look at the reasoning: punishment vs approval vs law vs principles.

4. Treating Erikson as only for childhood

   • Wrong: Stopping at identity.

   • Fix: Know the adult stages: intimacy, generativity, integrity.

5. Overstating critical periods for humans

   • Wrong: Claiming most human traits have strict critical periods like imprinting.

   • Fix: Many human developments are better described as sensitive periods (more flexible), though early experience still matters.

6. Mixing up parenting styles (authoritative vs authoritarian)

   • Wrong: Thinking “authoritative” means strict and cold.

   • Fix: Authoritative = high warmth + high standards. Authoritarian = low warmth + high control.

7. Misreading Strange Situation patterns

   • Wrong: Thinking avoidant means “independent and fine.”

   • Fix: Avoidant often reflects suppressed attachment signals; the child may still be stressed internally.

8. Thinking Freud and Erikson describe the same conflicts

   • Wrong: Using Freud terms (oral/anal) to answer an Erikson prompt (trust/autonomy).

   • Fix: Freud = erogenous-zone conflicts; Erikson = social crisis/tasks.

6. Memory Aids & Quick Tricks

7. Quick Review Checklist

• You can name prenatal stages (germinal, embryonic, fetal) and what makes embryonic especially vulnerable.

• You can define teratogen and give core examples (especially alcohol).

• You can distinguish secure, avoidant, anxious/ambivalent, disorganized attachment by reunion behavior.

• You can identify Baumrind’s parenting styles, especially authoritative vs authoritarian.

• You can match Piaget stages to: object permanence, egocentrism, conservation, abstract reasoning.

• You know all 8 Erikson stages and can apply identity, intimacy, generativity, integrity.

• You can classify Kohlberg reasoning as punishment, approval/law, or principles.

• You can recognize Freud’s stages by age and theme (oral, anal, phallic, latency, genital).

• You remember aging basics: fluid declines, crystallized holds/raises, and what dementia/Alzheimer’s generally imply.

You’ve got this—if you can do fast vignette matching with the “tells,” you’re exam-ready.