What is Developmental Psychology?

Developmental psychology studies systematic changes and continuities that occur from birth to death. These changes arise from physical maturation, cognitive growth, and social experiences.

Nature, Nurture & Culture in Development

Universal Genetically Determined Capacities

Some developmental processes are biologically primed, such as:

• Language acquisition
• Motor development

Environmental Influences

Children’s traits are shaped by their surroundings. Different environments emphasise different abilities depending on survival or cultural needs.

Parenting & Cultural Context

Parenting styles and cultural values interact with biology to shape temperament, skills, and developmental timelines.

Examples of Cultural Differences in Motor Development

• Annette Hamilton’s study (Indigenous Australian infants):
  Infants carried on caregivers’ backs with strong sitting support reached motor milestones earlier.
• SIDS prone-positioning effect:
  After prone sleeping was linked to SIDS, parents avoided tummy-time; many children showed delayed motor skills like head lifting and arm propping.

Major Theoretical Approaches

Psychoanalytic Theory (Freud)

Behaviour arises from interactions between the conscious and unconscious mind (id, ego, superego).

Cognitive Developmental Theory (Piaget)

Cognitive abilities evolve through biological maturation and environmental interaction. Development occurs through fixed stages.

Social Cognitive Theory (Bandura)

Development is shaped by personal experiences, observing others, and environmental influences.

Ethological Theory (Bowlby & Ainsworth)

Focuses on evolutionary roots of behaviour; attachment systems develop to ensure survival.

Psychosocial Theory (Erikson)

Development involves changes in self-concept, identity, and social roles across the lifespan.

Biological Stages of Prenatal Development

1. Zygote
2. Blastocyst
3. Embryonic period — period of greatest sensitivity
4. Foetal period

Sensitive Periods & Teratogens

• Sensitive periods: Times when the body is highly susceptible to environmental disruption.
• Teratogens: Environmental agents that impair prenatal development.
• Embryonic period is the most vulnerable.
• The first 3 years are crucial for brain development, myelination, and white-matter growth. Early trauma can have long-term impacts.

Piaget’s Theory of Cognitive Development

Piaget proposed that children are active learners and think qualitatively differently from adults. Development involves balancing new and existing knowledge through:

• Assimilation: Fitting new information into existing schemas
• Accommodation: Modifying schemas for new information
• Equilibration: Maintaining cognitive balance

Piaget’s 4 Stages

1. Sensorimotor (0–2):
Object permanence; understanding the world through sensory experiences

2. Pre-operational (2–7):
Symbolic thought, egocentrism, lack of conservation

3. Concrete operations (7–11):
Logical thinking with concrete objects; mental operations

4. Formal operations (12+):
Abstract and hypothetical thinking

Other Cognitive Theories

Vygotsky’s Sociocultural Theory

• Emphasises social interaction, cultural tools, and scaffolding in learning.

Information Processing Approach

• Focuses on neural maturation and specific cognitive functions such as memory, attention, and language.

Gender Development

Modern developmental psychology recognises a spectrum of gender identities and acknowledges both biological and environmental influences.

Gender Stereotypes & Socialisation

Expectations for how children “should” behave are reinforced through:

• Parenting practices
• Educational systems
• Media
• Toy marketing (pink vs blue)

Research Examples

Girl vs Boy Toys Experiment

• Children were dressed as the opposite gender and assigned new names.
• Adults unknowingly treated them based on gender stereotypes.
• Encouraging or restricting certain toys can actually influence brain development (e.g., spatial awareness).

Jack-in-the-Box Experiment

• Same startled reaction was labelled fear for girls but anger for boys.
• Shows how adults interpret children’s emotions through gendered lenses.

Early Gender Identity

• By age 2, children recognise themselves as a boy or girl.
• Gender understanding becomes more rigid during early childhood due to intense socialisation.

Adolescence

Adolescents form more nuanced gender identities influenced by:

• Puberty
• Increased social mixing
• Social media
• Expanding worldviews

Stereotypes vs Research Findings

Stereotype	Research Result
Males are more aggressive	Males → physical; females → relational aggression
Females are more social	Higher empathy/social connection, but culturally shaped
Males are more analytical	Differences are minimal
Males are more rational	No evidence
Males have greater spatial/maths ability	Slight average differences; largely training/socialisation

Theories of Gender Development

Psychoanalytic (Freud)

Gender identity stems from resolving conflicts in the phallic stage (Oedipus/Electra complexes).
Modern psychology views this as outdated.

Biological Basis

• Chromosomes (XX, XY)
• Hormones influence secondary sex characteristics
• Evolutionary explanations based on maximising reproductive success
• Modern research highlights:
  • Testosterone is socially modulated
  • Biological determinism is limited
  • Gender is fluid, not binary

Cognitive Developmental Theory (Piaget & Kohlberg)

Stages of gender understanding:

• Gender identity (2–3): “I am a boy/girl.”
• Gender stability (4–5): Gender is stable over time.
• Gender consistency (6–7): Gender stays constant across situations.

Kohlberg emphasised the importance of biological recognition (genitalia) and cognitive maturation (conservation).

Gender Schema Theory (Sandra Bem)

Children build schemas about gender from cultural norms and then actively seek experiences that confirm them.

Social Cognitive Theory (Bandura)

Gendered behaviours develop through:

• Attention
• Retention
• Reproduction
• Motivation

This occurs within triadic reciprocal determinism: behaviour, personal characteristics, and environment all influence each other.

Moral Development

Piaget

• Morality of constraint: Young children judge right/wrong based on consequences.
• Morality of cooperation: Older children consider intentions.

Kohlberg’s Stages

• Pre-conventional: Avoid punishment, seek rewards
• Conventional: Follow rules, desire social approval
• Post-conventional: Personal ethics and justice

Moral Disengagement

The discrepancy between moral reasoning and moral behaviour.
People justify harmful behaviour through:

1. Excusing (justifying)
2. Obscuring (minimising)
3. Vilifying the victim