DEVELOPMENTAL PSYCHOLOGY
MASTER CHEAT SHEET (Theories of
Development)
1. JEAN PIAGET – Cognitive Development (Key Concept: How children learn/think
changes over time)
Stage 1: Sensorimotor (Birth to 2 years)
o Key Event: Experience world through senses (touching, mouthing).
o Milestone: Object Permanence (Knowing an object still exists even if you
can't see it - e.g., Peek-a-boo).
Stage 2: Preoperational (2 to 7 years)
o Key Event: Uses words and images/symbols. Pretend play.
o Limitation: Egocentrism (Cannot see things from another's perspective).
Lack of Conservation (thinks a tall thin glass has more water than a short wide
one).
Stage 3: Concrete Operational (7 to 11 years)
o Key Event: Logical thinking about concrete events.
o Milestone: Conservation mastered (understands mass/volume stays same).
Math operations.
Stage 4: Formal Operational (12 years to Adulthood)
o Key Event: Abstract reasoning.
o Milestone: Abstract logic, moral reasoning, hypothesis testing.
2. ERIK ERIKSON – Psychosocial Development (Key Concept: Life is a series of
conflicts/crises we must resolve)
Infancy (0-1 yr): Trust vs. Mistrust
o Conflict: Are needs met? -> Hope/Trust.
Early Childhood (1-3 yrs): Autonomy vs. Shame/Doubt
o Conflict: Toddlers learning independence (toilet training). -> Will.
Preschool (3-6 yrs): Initiative vs. Guilt
o Conflict: Initiating tasks/play. -> Purpose.
School Age (6-12 yrs): Industry vs. Inferiority
o Conflict: Academic/Social success. -> Competence.
Adolescence (12-19 yrs): Identity vs. Role Confusion
o Conflict: "Who am I?" (Peer pressure is huge here). -> Fidelity.
Young Adulthood (20-40 yrs): Intimacy vs. Isolation
o Conflict: Forming relationships/love. -> Love.
Middle Adulthood (40-65 yrs): Generativity vs. Stagnation
o Conflict: Contributing to society/family (Mid-life crisis zone). -> Care.
Late Adulthood (65+ yrs): Integrity vs. Despair
o Conflict: Looking back on life. Regret or satisfaction? -> Wisdom.
MASTER CHEAT SHEET (Theories of
Development)
1. JEAN PIAGET – Cognitive Development (Key Concept: How children learn/think
changes over time)
Stage 1: Sensorimotor (Birth to 2 years)
o Key Event: Experience world through senses (touching, mouthing).
o Milestone: Object Permanence (Knowing an object still exists even if you
can't see it - e.g., Peek-a-boo).
Stage 2: Preoperational (2 to 7 years)
o Key Event: Uses words and images/symbols. Pretend play.
o Limitation: Egocentrism (Cannot see things from another's perspective).
Lack of Conservation (thinks a tall thin glass has more water than a short wide
one).
Stage 3: Concrete Operational (7 to 11 years)
o Key Event: Logical thinking about concrete events.
o Milestone: Conservation mastered (understands mass/volume stays same).
Math operations.
Stage 4: Formal Operational (12 years to Adulthood)
o Key Event: Abstract reasoning.
o Milestone: Abstract logic, moral reasoning, hypothesis testing.
2. ERIK ERIKSON – Psychosocial Development (Key Concept: Life is a series of
conflicts/crises we must resolve)
Infancy (0-1 yr): Trust vs. Mistrust
o Conflict: Are needs met? -> Hope/Trust.
Early Childhood (1-3 yrs): Autonomy vs. Shame/Doubt
o Conflict: Toddlers learning independence (toilet training). -> Will.
Preschool (3-6 yrs): Initiative vs. Guilt
o Conflict: Initiating tasks/play. -> Purpose.
School Age (6-12 yrs): Industry vs. Inferiority
o Conflict: Academic/Social success. -> Competence.
Adolescence (12-19 yrs): Identity vs. Role Confusion
o Conflict: "Who am I?" (Peer pressure is huge here). -> Fidelity.
Young Adulthood (20-40 yrs): Intimacy vs. Isolation
o Conflict: Forming relationships/love. -> Love.
Middle Adulthood (40-65 yrs): Generativity vs. Stagnation
o Conflict: Contributing to society/family (Mid-life crisis zone). -> Care.
Late Adulthood (65+ yrs): Integrity vs. Despair
o Conflict: Looking back on life. Regret or satisfaction? -> Wisdom.
