Piaget, Erikson, and Vygotsky: Key Concepts in Developmental Psychology

Sensorimotor (Birth-2y)

Hallmarks: Object permanence, goal‑directed actions, sensory + motor exploration. Limitations: No abstract thought. Example: 8‑month‑old stops looking for a hidden toy → object permanence not fully developed.

Preoperational (2-7y)

Hallmarks: Symbolic thought, pretend play, language growth. Limitations: Egocentrism, centration, no conservation, irreversibility. Example: Child thinks taller glass has more water than shorter one.

Concrete Operational (7-11y)

Hallmarks: Logical thinking for concrete tasks, conservation, reversibility, classification, seriation. Limitations: Struggle with abstract ideas. Example: Understands water volume is unchanged despite container shape.

Formal Operational (11+y)

Hallmarks: Abstract reasoning, hypothetical‑deductive thinking, systematic problem‑solving. Limitations: Adolescent egocentrism (imaginary audience, personal fable). Example: Teen designs a controlled experiment to test a hypothesis.

Trust vs. Mistrust (Birth-1y)

Virtue: Hope. Key Task: Develop trust when needs are met consistently. Example: Infant cries, parent responds promptly → trust builds.

Autonomy vs. Shame & Doubt (1-3y)

Virtue: Will. Key Task: Develop independence in tasks like feeding/dressing. Example: Toddler insists on choosing their own clothes.

Initiative vs. Guilt (3-6y)

Virtue: Purpose. Key Task: Initiate activities and assert control over environment. Example: Child organizes a pretend play scenario for friends.

Industry vs. Inferiority (6-12y)

Virtue: Competence. Key Task: Develop skills, pride in accomplishments. Example: Schoolchild feels capable after learning multiplication.

Identity vs. Role Confusion (12-18y)

Virtue: Fidelity. Key Task: Develop personal identity and sense of self. Example: Teen explores different hobbies and friend groups.

Intimacy vs. Isolation (18-40y)

Virtue: Love. Key Task: Form deep, meaningful relationships. Example: Adult maintains a committed partnership.

Generativity vs. Stagnation (40-65y)

Virtue: Care. Key Task: Contribute to society, support next generation. Example: Mentoring younger coworkers.

Integrity vs. Despair (65+y)

Virtue: Wisdom. Key Task: Reflect on life with satisfaction or regret. Example: Elder feels proud of their life choices.

Sociocultural Theory - Main Idea

Cognitive development is shaped by social interaction and culture. Learning happens through guidance from more knowledgeable others (MKOs).

Zone of Proximal Development (ZPD)

The gap between what a learner can do independently and what they can do with help. Learning is maximized when tasks are within the ZPD.

More Knowledgeable Other (MKO)

Anyone with more skill/understanding in a task (teacher, peer, parent). Guides the learner through the ZPD.

Scaffolding

Temporary support given by the MKO to help the learner master a task. Gradually removed as independence increases.

Private Speech

Talking to oneself to plan or guide behaviour. Transitions to inner speech with age.

Role of Culture in Learning

Cognitive tools (language, symbols, customs) are passed down socially. Culture shapes what and how we learn.

Language as a Tool for Thought

Language is the primary way knowledge is transmitted. Thinking develops first socially, then internally (social → private → inner speech).