Developmental Psychology - TCE Psychology (Tasmania)
“Explain theories of human development”
Developmental psychology studies how people change across the lifespan, including cognitive development (Piaget), attachment (Bowlby and Ainsworth), psychosocial stages (Erikson) and moral reasoning (Kohlberg).
What this dot point is asking
Nature versus nurture
A core debate asks whether development is driven mostly by genetics and maturation (nature) or by experience and environment (nurture). Most psychologists now take an interactionist view, that genes and environment work together. Twin and adoption studies are used to estimate the influence of each.
Cognitive development: Piaget
Jean Piaget proposed children actively build knowledge through schemas (mental frameworks), using assimilation (fitting new information into existing schemas) and accommodation (changing schemas to fit new information). He described four stages:
- Sensorimotor (0 to 2 years): learning through senses and movement; achieving object permanence.
- Preoperational (2 to 7 years): symbolic thinking but egocentrism and a lack of conservation.
- Concrete operational (7 to 11 years): logical thinking about concrete objects; conservation achieved.
- Formal operational (11 plus): abstract and hypothetical reasoning.
Piaget's conservation tasks showed young children think a taller glass holds more water even when the amount is unchanged. Critics argue he underestimated children's abilities. Lev Vygotsky offered an alternative, stressing social and cultural learning through the zone of proximal development and scaffolding by more knowledgeable others.
The understanding that objects continue to exist even when they cannot be seen, heard or touched, which Piaget said develops in the sensorimotor stage.
Attachment
John Bowlby argued attachment is an innate, evolutionary bond that aids survival, with a critical period in the early years. He proposed monotropy (a primary attachment figure) and an internal working model that shapes later relationships.
Mary Ainsworth's "Strange Situation" (1970) observed infants' reactions to separation and reunion with a caregiver, identifying attachment types: secure, insecure-avoidant and insecure-resistant. Secure attachment was linked to sensitive, responsive caregiving. Harlow's monkey studies (1958) showed infant monkeys preferred a soft cloth "mother" over a wire one that provided food, suggesting comfort matters more than feeding for attachment.
Harlow's research with rhesus monkeys challenged the idea that attachment forms simply because a caregiver provides food. Contact comfort, the warmth and security of physical contact, was more important to the infant monkeys than feeding.
Psychosocial development: Erikson
Erik Erikson described eight stages across the whole lifespan, each with a conflict to resolve, such as trust versus mistrust in infancy, identity versus role confusion in adolescence, and integrity versus despair in old age. Successfully resolving each stage builds a healthy personality.
Moral development: Kohlberg
Lawrence Kohlberg studied moral reasoning using dilemmas such as the Heinz dilemma. He proposed three levels:
- Preconventional: morality based on rewards and punishment.
- Conventional: morality based on social approval and law.
- Postconventional: morality based on abstract ethical principles.
Read the scenario
A 4-year-old says a tall thin glass holds more juice than a short wide glass, although the same amount was poured into each. The task is to name the stage and concept.
Identify the age and behaviour
At about 4 years the child is in the preoperational stage (2 to 7 years), where symbolic thinking is present but logical operations are not yet reliable.
Name the missing concept
The child lacks conservation, the understanding that quantity stays the same despite a change in appearance. Because they judge by the single dimension of height, they conclude the taller glass holds more. This is the classic evidence Piaget used for the preoperational stage.
The ages Piaget gave are approximate averages, not strict cut-offs. Children progress through the stages in the same order but at different rates, and later research suggests some abilities appear earlier than Piaget claimed. Avoid stating that a skill must appear at an exact age.
Evaluating developmental theories
No single theory captures development. Piaget mapped how thinking changes but underestimated children and downplayed culture; Vygotsky corrected this by stressing social learning. Bowlby's attachment theory is supported by Ainsworth and Harlow but the idea of a fixed critical period is now softened to a more flexible sensitive period. Erikson extended development across the whole lifespan, which fits modern views, though his stages are hard to test precisely. Kohlberg's moral stages were criticised for being based mainly on male samples and for valuing abstract justice over care. A strong TASC answer names the theory, its supporting evidence and a limitation, then notes that the theories are complementary rather than competing.
Putting it together
When the exam describes a child or a developmental change, first identify the domain (cognitive, attachment, psychosocial or moral) and the matching theorist, then apply the specific stage or concept and, where the question asks, evaluate it. These theories help explain how thinking, relationships, identity and morality develop, and they link directly to wellbeing across the lifespan and to the nature versus nurture debate that runs through the whole course.
Exam-style questions
Questions in the style of TASC exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
Practice6 marksDescribe Ainsworth's Strange Situation and identify the three attachment types it produced. Outline one factor linked to secure attachment.Show worked answer →
This is a knowledge item marked on Criterion 3. Describe the method, list the types, then give a factor.
- The procedure
- Mary Ainsworth's Strange Situation (1970) was a controlled observation in which an infant was observed through a series of episodes involving separation from and reunion with the caregiver, and the presence of a stranger. Reactions to separation, to the stranger and especially to reunion were recorded.
- The three types
- Secure attachment (distressed at separation, easily comforted at reunion), insecure-avoidant (little distress, avoids the caregiver at reunion) and insecure-resistant (very distressed, hard to comfort, may resist contact at reunion).
- A factor
- Secure attachment was linked to sensitive, responsive caregiving, where the caregiver reads and meets the infant's needs consistently.
Markers reward an accurate description of the observation, the three correctly labelled types, and a valid factor tied to caregiving.
Practice9 marksCompare Piaget's and Vygotsky's accounts of cognitive development. Evaluate the claim that Piaget underestimated young children's abilities, referring to evidence.Show worked answer →
This is an extended-response item marked on Criteria 3 and 7. Compare the two theories, then evaluate the criticism.
- Comparison
- Piaget saw cognitive development as a largely individual process: children actively construct knowledge through schemas, passing through universal stages (sensorimotor, preoperational, concrete operational, formal operational) as they mature. Vygotsky stressed the social and cultural roots of thinking: development is driven by interaction with more knowledgeable others, working within the zone of proximal development with scaffolding. Piaget emphasises maturation and discovery; Vygotsky emphasises social and language-based learning.
- Evaluating the underestimation claim
- Piaget's conservation and egocentrism tasks suggested young children lack key abilities, but later research argued his tasks were confusing or verbally demanding. Studies using simpler, child-friendly methods showed some children succeed earlier than Piaget claimed, supporting the criticism. Against this, the stages still describe a robust developmental order, so the criticism refines rather than overturns the theory.
- Judgement
- A balanced answer accepts that Piaget likely underestimated abilities because of task design, while crediting his enduring insight that thinking changes qualitatively with age.
Markers reward a genuine comparison, use of evidence on task design, and a two-sided judgement.