Developmental Psychology: Lifespan Growth and Change
Developmental psychology studies systematic change across the lifespan — cognitive, emotional, social, moral, and physical. Its great theorists — Piaget, Erikson, Vygotsky, Kohlberg, Bowlby, Ainsworth — produced stage-based models still central to CSS preparation.
Systematic, age-related change in behaviour, thinking, emotion, and social functioning across the lifespan, produced by the interaction of biological maturation, environmental experience, and individual agency.
Jean Piaget — Cognitive development
Swiss psychologist Jean Piaget (1896–1980) revolutionised the study of children's thinking. He proposed four invariant stages:
- Sensorimotor (0–2 years) — knowledge through senses and motor action; key achievement is object permanence (~8 months).
- Pre-operational (2–7) — symbolic thought, language explosion; limited by egocentrism, animism, and failure to conserve mass, number, or liquid quantity.
- Concrete operational (7–11) — logical operations on concrete objects; conservation mastered; reversibility achieved.
- Formal operational (11+) — abstract, hypothetical-deductive reasoning; the adolescent can think about thought itself.
Piaget's core constructs include schemas, assimilation (fitting new information into existing schemas), and accommodation (modifying schemas to fit new information).
Lev Vygotsky — Sociocultural development
Russian psychologist Lev Vygotsky (1896–1934) stressed the social and cultural nature of cognitive development. Two of his terms are CSS staples:
- Zone of Proximal Development (ZPD) — the gap between what a learner can do alone and what they can do with skilled support.
- Scaffolding — adjustable assistance provided by a more competent partner, gradually withdrawn as the learner masters the task.
Vygotsky emphasised that language is the primary tool of thought; private speech evolves into inner speech that mediates cognition.
Erik Erikson — Psychosocial development
Erik Erikson (1902–1994) extended Freud's psychosexual stages into a lifespan model of eight crises, each pitting a developmental need against a social challenge:
| Stage | Age | Crisis | Virtue if resolved |
|---|---|---|---|
| 1 | 0–1 | Trust vs. Mistrust | Hope |
| 2 | 1–3 | Autonomy vs. Shame & Doubt | Will |
| 3 | 3–6 | Initiative vs. Guilt | Purpose |
| 4 | 6–12 | Industry vs. Inferiority | Competence |
| 5 | 12–18 | Identity vs. Role Confusion | Fidelity |
| 6 | 18–40 | Intimacy vs. Isolation | Love |
| 7 | 40–65 | Generativity vs. Stagnation | Care |
| 8 | 65+ | Integrity vs. Despair | Wisdom |
Lawrence Kohlberg — Moral development
Building on Piaget, Lawrence Kohlberg (1927–1987) used moral dilemmas (the famous Heinz dilemma) to identify three levels, each with two stages:
- Pre-conventional — Stage 1 obedience/punishment; Stage 2 instrumental exchange.
- Conventional — Stage 3 interpersonal accord ("good boy / nice girl"); Stage 4 law and order.
- Post-conventional — Stage 5 social contract; Stage 6 universal ethical principles.
Carol Gilligan's critique (In a Different Voice, 1982) argued that Kohlberg's framework privileged a masculine "ethic of justice" over a feminine "ethic of care".
- Piaget = cognitive stages and conservation.
- Vygotsky = ZPD, scaffolding, sociocultural mediation.
- Erikson = eight psychosocial crises across the lifespan.
- Kohlberg = six moral stages in three levels.
- Bowlby & Ainsworth = attachment theory and the Strange Situation.
Sigmund Freud — Psychosexual stages
Freud's five-stage model — oral (0–1), anal (1–3), phallic (3–6), latency (6–12), genital (12+) — emphasises early fixations and the Oedipus complex. Although largely superseded for empirical work, it remains important historically and as the foundation Erikson built upon.
John Bowlby and Mary Ainsworth — Attachment
John Bowlby (1907–1990) proposed that infants form a biologically driven attachment bond with a primary caregiver, evolved to ensure survival. His phases of attachment culminate in a secure base from which to explore.
Mary Ainsworth's Strange Situation (1969) classified infant attachment into:
- Secure (~65%) — uses caregiver as base; distressed by separation; comforted by reunion.
- Insecure-avoidant (~20%) — minimal distress, ignores caregiver on reunion.
- Insecure-resistant/ambivalent (~10–15%) — intense distress, ambivalent on reunion.
- Disorganised (Main & Solomon, 1986) — contradictory, fearful behaviour; often linked with maltreatment.
Adolescence and adulthood
G. Stanley Hall (1904) characterised adolescence as "storm and stress". James Marcia (1966) refined Erikson's identity stage into four identity statuses: diffusion, foreclosure, moratorium, and achievement, based on exploration and commitment.
Adult development includes Levinson's seasons of life, the midlife transition, and emerging-adulthood frameworks by Jeffrey Arnett (2000) for the 18–25 age group.
For the exam, attach stage models to a specific theorist and target age band. A common error is to confuse Kohlberg's six moral stages with Erikson's eight psychosocial crises. Memorise the ages: Piaget caps formal operations at ~11, Kohlberg's post-conventional thinking emerges in adolescence onward, Erikson's stage 5 (identity) corresponds to ages 12–18.
Old age and the lifespan view
Recent research treats development as lifelong. Erikson's eighth stage, Cumming and Henry's disengagement theory (1961), and the more positive activity theory describe successful ageing. The WHO's healthy ageing framework integrates cognitive, social, and physical dimensions.
In Pakistan, intergenerational living arrangements, the salience of religion in identity formation, and gendered education access shape developmental trajectories in ways that universal stage models alone cannot capture — a reminder that culture matters as much as biology in development.