Individual Development
What you must understand
Individual development in the QCAA course centres on how psychological change occurs across the lifespan and how it is studied. You need to distinguish physical, cognitive and social-emotional development, and to know the difference between continuous (gradual, cumulative) and discontinuous (stage-based) accounts of change. Be able to outline the nature–nurture interaction, the concepts of critical and sensitive periods, and the role of maturation. You should be able to describe and evaluate the major frameworks: Piaget's stages of cognitive development (sensorimotor, preoperational, concrete operational, formal operational) with the mechanisms of assimilation, accommodation and equilibration; Vygotsky's sociocultural theory, including the zone of proximal development and scaffolding; Erikson's psychosocial stages; and attachment theory, including Ainsworth's strange-situation classifications (secure, insecure-avoidant, insecure-resistant) and Baumrind's parenting styles. Know how longitudinal and cross-sectional designs differ, and the strengths and limitations of each.
Traps in questions
Students routinely muddle assimilation with accommodation - assimilation fits new experience into an existing schema; accommodation changes the schema. Do not describe Piaget's stages as ages to memorise; they are qualitative shifts in thinking. Vygotsky is often confused with Piaget: Vygotsky emphasises social interaction and language as drivers, Piaget emphasises individual active construction. Another trap is treating attachment classifications as parenting styles (they are not) or claiming a sensitive period is a critical period. When asked to evaluate a design, name attrition and cohort effects for longitudinal, and cohort effects for cross-sectional.
Rule of thumb
For any developmental claim, ask three questions: What changes? What drives the change (biology, experience, or both)? How would we know? This keeps description anchored to evidence.
Worked example: A question asks why a child who can conserve number fails a conservation-of-volume task. Answer: the child is likely in the preoperational stage and is centrating on one perceptual dimension; the limitation is cognitive, not motivational.