Everything

Infancy

Developmental Psychology

• Psychology is broad – Clinical, Social, Developmental, others

• Developmental psychology investigates how people grow, change, and adapt throughout their lifespan

• Infancy → Childhood → Adolescence → Adulthood → Late adulthood

• Integrates scientific research, psychological theory, and observational methods to understand transformations in behavior, cognition, and emotions over time

What Does Developmental Psychology Study?

• Physical Development - Growth patterns, motor skills, puberty, aging processes.

• Cognitive Development - Changes in thinking, problem-solving, language acquisition, and memory from infancy to older adulthood.

• Social and Emotional Development - Attachment and relationships, self-concept, emotional regulation, moral reasoning, and personality formation across different life stages.

Typical Questions in Developmental Psychology

• How do genetic factors and the environment (nature vs. nurture) interact to shape development?

• Why do children form certain attachment styles, and how do these styles impact later relationships?

• What drives cognitive milestones (e.g., learning to speak, read, reason)?

• How do societal and cultural contexts influence growth and identity formation?

• What factors contribute to resilience or vulnerability across different life stages?

Why Study Developmental Psychology

• Insight into Human Growth - Understand how people evolve physically, cognitively, and socially across the lifespan.

• Improving Quality of Life - Inform educational practices, parenting approaches, healthcare decisions, and social policies.

• Broader Impact - Promote healthier childhood development, support adolescents through transitions, and improve care for older adults.

• Connection to Other Fields - Overlaps with Clinical Psychology (e.g., diagnosing developmental disorders), Social Psychology (e.g., peer influence in adolescence), and more.

Infancy

• How do we become the people we are?

• Infancy - first 2 years of life - we all start life in a very primitive state and develop rapidly in the first two years

• A remarkable transformation in 730 days!!

• Weight triples and length increases by 50%

• Brain grows to 80% adult volume and cortex doubles in surface area

• Co-ordinated reach, locomotion, first words

Why Study Infancy?

• Foundations of later cognition, personality, and health

  • expressive vocabulary measured between 16 - 30 months significantly predicted Grade‑9 exam scores at age 15

  • even after controlling for SES and other early‑life factors

• Period of maximal neural and behavioural plasticity

  • deaf infants who receive a cochlear implant before 12 months of age develop speech intelligibility and language scores indistinguishable from normal‑hearing peers

  • implantation after the second year yields substantially poorer outcomes

• Practical relevance: parenting, clinical screening, public policy

  • Kangaroo Mother Care - continuous skin‑to‑skin contact begun immediately after birth reduces mortality and accelerates neurodevelopment in pre‑term and low‑birth‑weight infants

  • many countries now mandate KMC units in neonatal wards

  • saves an estimated 150,000+ infant lives annually

Historical Perspectives

• Nature (Plato)

  • everything that the adult will become is already in there

  • capabilities, skills, personality – genetically encoded

  • development is mostly maturation

• Nurture (John Locke and William James)

  • blank slate bombarded with sensory information

  • development is making sense of the information by forming associations

Nature AND Nurture

• Gene-environment interactions (psychopaths)

  • Impact of genes on behaviour depends on the environment that the behaviour develops

• Nurture via nature (musicians)

  • Genetic predispositions drive us to seek or create particular environments that then enhance the behaviour

• Gene expression (nutrition and cognitive development)

  • Genes turn on in response to specific environmental events

• Epigenetics (maternal care and stress)

  • Genes dynamically respond moment to moment to environmental conditions

Sensory Systems

• Evolution equips neonates for immediate survival tasks

• All 5 systems functional but unevenly mature

• Vision least developed; touch & smell most advanced

• Early biases tune infants to caregivers and nutrition

• Newborns track top‑heavy, face‑like patterns

• sucrose elicits relaxed facial expression and ingestion; bitter triggers aversive “gape.”

Vision

• New‑born acuity ≈ 20/500 (WHO “profound impairment”)

• Fixed focal distance ≈ 20 cm (stiff lens) - perfect for face‑to‑face bonding

• Accommodation begins to emerge ~8 - 10; adult‑like dynamic focusing is reached by 6 - 7 mo

• Adult‑level acuity & binocular depth by ~8 mo

• Synaptic density in primary visual cortex overproduces to ~150 % of adult levels by 4 -8 mo

• Redundant connections for experience‑driven refinement – rapid pruning as crawling begins

Hearing

• Cochlea mature by 24 gestational wk; womb filters high freqs

• Late‑gestation EEG shows rhythm encoding of speech‑like patterns

• New‑borns preferentially suck to hear mother’s voice and native prosody

• Categorical speech perception present at birth – general – but by 8 – 12 months sensitivity narrows to native language only

• Music: preference for consonant over dissonant intervals by 3 mo

• Sound localisation accurate to ±6° by 5 mo

• Categorical speech perception present at birth

• Eimaset al. (1971) – 1 and 4 month old infants

• 2 syllables – “ba” and “pa”

• Conditioned to respond to “pa” (increase sucking)

• Present ba/pa pairs with varying interval (0ms to 80ms)

• Short intervals – no change in sucking

• Clear increase at categorical boundary (20ms – 40ms)

• Step change similar to adult speech perception

Touch

• Significant development before birth

• Dense mechanoreceptors - cutaneous receptors first appear along the lips at 7‑8 gestational weeks and cover the entire body by ≈20 weeks

• Reflexes triggered by tactile cues (rooting, grasp)

• Newborns can detect object shape and texture by mouthing

• Feel pain but descending inhibition immature - require analgesia

• Birth – big change from fluid to air/clothing/skin – rapid recalibration of circuits in first weeks

• By 9 mo integrate touch with vision and proprioception – body rep

Taste and Smell

• Critical for feeding and protection

• Essentially mature at birth

• Taste – innate sweet for energy and bitter for toxins

• Fetal and breast‑milk exposure to flavours (e.g., carrot, garlic) leads infants to later accept those foods more readily

• Smell

• Day‑1 orientation to maternal breast‑pad odor

• By 1 mo distinguish mother’s T‑shirt from stranger’s

• 2024 fMRI: maternal scent dampens infant amygdala response to threat faces

Timelines

Early Motor Programs

Reflex

• Present at or within days of birth ↠ “built‑in” motor circuits

• Reflexes solve immediate survival problems while cortex is immature

• Feeding – rooting and sucking

• Protection – Moro (startle)

• Attachment – palmer

• Critical – these should fade within about 4 months to be replaced by voluntary controlled movement

• Head control ≈ 6 wk (prone lift), full antigravity by 3 mo

• Goal‑directed reach emerges 3–4 mo as vision‑hand mapping stabilizes

• Rolling → crawling → cruising sequence between 4–10 mo, but cultural variation large.

Emotion & Temperament

• Birth – 2 mo: two global states - distress / excitement vs contentment

• 2 – 4 mo: discrete joy & surprise appear

• 5 – 7 mo: anger, fear, sadness identifiable in facial‑action coding

• 9 – 12 mo: social‐referencing to caregiver’s emotional cues

• Early expressions hard‑wired yet rapidly shaped by caregiver mirroring

• Temperament - biologically‑based individual differences in reactivity & self‑regulation

• Temperament captures early‑life individuality—observable long before personality traits can be measured

• Thomas & Chess axes: Biological regularity, Hedonic tone, Approach / withdrawal to novelty

• Easy ≈ 40 % (regular, positive, approach)

• Difficult ≈ 10 % (irregular, negative, withdrawal)

• Slow‑to‑warm ≈ 15 % (low activity, mild negativity, gradual approach)

• Overall infancy‑to‑adulthood correlation modest, but …

• Extreme temperaments often persist, although …

• Caregiving and later self‑control can amplify or mute early tendencies

• Behavioural inhibition at 4 mo → introverted, anxiety‑prone adults

• “under‑controlled” 3‑y‑olds had poorest health & finances at 45 y

• Temperament sets initial parameters, environment fine‑tunes emotional style.

• Optimal development when caregiver response matches child temperament.

• Difficult babies need consistent, sensitive routines

• Easy babies still need stimulation

• Parent training!!!

• Soothing, feeding, and sleep

Studying Babies

• No instructions, no verbal reports

• Must rely on natural behaviours and reflexes

• Measures: looking, sucking, reaching

• Changes in these correlate with things of interest – infer thoughts from actions

• Indirect inference, sensitive to fatigue/state changes, require converging methods for firm conclusions

Preferential Looking

• Fantz (1960s) - infants look longer at face‑like, high‑contrast patterns

• Infant reclines on a parent’s lap or crib mattress.

• Display board shows Stimulus A on one side, Stimulus B on the other, each positioned at the optimum focal distance (~20 cm

• Eye tracking monitors gaze

• Positions are switched to control for side bias

• 0-48 hr newborns - High‑contrast schematic face (40%) vs. scrambled face (15%)

Physiological Additions

• confirm and extend behavioural findings

• Heart‑rate deceleration: sustained attention

• Pupil dilation / skin conductance: arousal

• EEG/ERP & fNIRS: cortical localisation

Key takeaways

• Newborns are prepared yet plastic—equipped with adaptive biases while remaining exquisitely moldable.

• Development is “nature via nurture”: genes provide ranges; environments tune trajectories.

• Methodological ingenuity drives discovery—how we ask dictates what we can know.

Later Life Development

• Old age generally considered 65+ (transition to retirement)

• But – 100 years ago life expectancy was 65-75 (ignoring child mortality)

• Now ~85

• Aging populations are a result of medical advancements, improved public health, and better nutrition.

• Decreasing birth rates, especially due to better educational and economic opportunities for women, contribute to the aging population.

• In 2017, for the first time, the number of people over 65 surpassed those under 5 globally.

An Aging Population

• Australia – proportion of the population aged over 65:

• 1901: Around 4%

• 1947: The proportion increased to about 8%.

• 1971: The figure rose to approximately 9%.

• 1991: The percentage climbed to 11.1%.

• 2011: The share reached 14.1%.

• 2021: The proportion further increased to 16%.

• 2056: Estimated 25%

Consequences

• Individual and Family-Level Consequences

• Health and Aged Care System Impact

• Economic and Workforce Impacts

• Urban Planning and Infrastructure

• Social and Cultural Implications

• Policy and Planning

• Global Inequities

• Aging is not just an individual experience - it is a societal transformation.

• The way we prepare for and respond to population aging will determine the sustainability, equity, and wellbeing of future societies.

• Not all countries age at the same speed

• Speed of aging - how long it takes for the proportion of people aged 65 and older to double (typically from 7% to 14%)

• France took about 120 years to double its 65+ population from 7% to 14% (from ~1860s to 1980).

• South Korea achieved the same demographic shift in just 18 years.

• Rapid aging – significant challenges.

Studying Aging

• Aging is not a one-size-fits-all – development across aging

• Young-old: 65–74 years

• Old-old: 75–84 years

• Oldest-old: 85+ years

• Centenarians: 100+ years

• Super-centenarians: 110+

Gerontology

• Gerontology - scientific study of aging and the issues that affect older individuals

• Promote healthy aging and independence

• Design effective public health policies

• Support families and caregivers

• Understand how to reduce ageism and stereotypes

• Broad field – Psychology, Sociology, Medicine, Public health, Economics, Policy and planning

Geropsychology

• Geropsychologist is a psychologist who specializes in the mental health and wellbeing of older adults

• Cognitive changes (e.g., memory, executive function)

• Emotional health (e.g., depression, anxiety, resilience)

• Personality development across the lifespan

• Adaptation to loss (e.g., bereavement, retirement, physical decline)

• Promoting autonomy, dignity, and purpose in older age

• Helping older adults navigate health systems and long-term care

• Supporting caregivers (often family members)

Personality in Older Adulthood

• Personality lectures – fairly stable across life, but some changes …

• Cross-sectional and longitudinal studies suggest general trends with age:

  • Agreeableness and Conscientiousness tend to

  • Neuroticism, Extraversion, and Openness tend to slightly

  • Average trends, individual differences are large

  • Best predictor of personality in older adulthood is personality earlier in life

Cognitive Function

• Declines largely reflect biological aging, disease processes, and cumulative health effects.

• Improvements arise from experience, emotional growth, brain adaptability, and lifestyle choices.

• Cognitive aging is highly variable - shape trajectories significantly through health behaviors, mental engagement, and social participation.

What Declines?

• Fluid intelligence: solve novel problems and process new information (e.g., mental speed, working memory) - tends to decline from midlife onward.

• Multitasking and divided attention often become more difficult.

• Processing speed slows.

Why?

• Neurological and Biological Changes – loss of volume, synapses, white matter

• Vascular changes

• Oxidative damage and inflammation

What Improves?

• Crystallized intelligence: Accumulated knowledge, vocabulary, and expertise remains stable or increases.

• Emotional reasoning, moral judgment, and life wisdom often deepen with age.

• Selective attention and memory can be preserved with engagement and training.

Why?

• Accumulated knowledge stored in long-term memory (less dependent on processing speed)

• Emotional maturity and wisdom

• Cognitive reserve

Neuroplasticity

• The aging brain remains plastic—it can form new connections with:

  • Mental stimulation

  • Physical exercise

  • Social interaction

Emotional Function in Later Life

• Better Emotional Regulation

  • Older adults generally report better emotional control and less negative affect than younger adults

  • Less reactive to daily stressors and more likely to let go of negative experiences

  • Socioemotional Selectivity Theory - as people age, they become more selective in their social networks

  • Motivation shifts from information-seeking (broad networks) to emotion-regulating goals (close, meaningful relationships)

Gene Cohen’s Stages of Development

• Four psychological phases in later life that reflect ongoing development, not just maintenance

• Cohen believed these phases were supported by neurological changes—particularly increased corpus callosum connectivity, allowing more integrative and creative thinking

Successful Aging

• Beyond simply living longer - living well

  • maintaining physical health, mental sharpness, social connection, and a sense of purpose across later life

• Not just avoiding disease

  • adaptation, engagement, and resilience

• Rowe & Kahn inspire preventative action: encouraging lifestyle choices that maximize healthspan.

• Baltes' SOC model offers realistic tools: recognizing that adaptation is a key part of thriving, not just "avoiding problems.“

• Together, they present a holistic picture: Prevention and resilience both matter.

Rowe and Kahn

• Some argue Rowe and Kahn’s model overemphasizes health and underemphasizes adaptability to illness or disability.

• Later research suggested that even people with chronic conditions can experience successful aging if they maintain wellbeing, meaning, and positive engagement.

Baltes SOC

• Selection, Optimization, and Compensation

• Focuses more explicitly on adaptive processes - how people adjust to gains and losses as they age.

• Rather than defining successful aging as simply being healthy, SOC highlights the strategies people use to adapt to aging and maintain a fulfilling life

Physical Activity

• Improving Physical Health: Exercise strengthens muscles, bones, and the cardiovascular system. It helps maintain mobility, balance, and flexibility, which are essential for daily activities and fall prevention.

• Enhancing Mental Health: Regular physical activity has been shown to reduce symptoms of depression and anxiety. It also promotes better sleep and cognitive function.

• Promoting Social Interaction: Group exercises, sports, and recreational activities provide opportunities for social engagement, which is beneficial for mental and emotional health.

Later Life Development

• Increased agreeableness and conscientiousness

• Decreased neuroticism and extraversion

• Prune social networks to focus on meaningful relationships (socio-emotional selectivity).

• Loneliness is not prevalent; most older adults maintain regular contact with family and friends.

• Often report high life satisfaction, contrary to stereotypes of depression and dissatisfaction.

• Feeling younger than one's chronological age is common and beneficial for health.

• Successful aging involves active choices and adaptation to life's changes.

• The earlier you prepare the better.

Moral Development

• Morality - organised system of values, rules, and feelings guiding behaviour

  • Moral codes – determining what is ‘right’ and what is ‘wrong’

  • Not correct or incorrect – more about what is acceptable and what isn’t

• Developmental psychology asks how those systems emerge and mature, not which rules are “correct.” - process focus NOT outcome focus

• Moral development is a long path, yet …

  • wherever we are on that path we think we know right from wrong

  • Very reluctant to bend whatever code we have

• Typically evolve from simple adherence to rules to complex ethical judgments

Social Learning

Bandura’s Bobo-doll Experiment (1963)

• 72 nursery-school children (3–6 yrs)

• Sit in a room with adult and Bobo

• 3 conditions – aggressive model, non-aggressive model, and no model

• Aggressive – 10 minutes of physical and verbal assault

• Then free play room with Bobo and other toys

• Aggressive model - more than twice physical and verbal aggression than either control

• 32% invented new attacks

• Non-aggressive modelling suppressed aggression below no modelling

• Observation alone created generalised aggression

• Flexibly recombined observed elements into new acts

• Modelling can inhibit aggression just as powerfully

4 Steps

• Attention - notice and focus on the model’s behaviour and context (salience, attractiveness, similarity )

• Retention - behaviour encoded and stored symbolically

• Motor Reproduction - physical and cog ability to translate stored code into action (includes practice and feedback)

• Motivation - reason to perform the behaviour (anticipated reward, avoidance of punishment)

Media Violence

• Bandura expanded the experiment

• Filmed adult – no change

• Cartoon cat instead of adult – no change

• All three versions showed the aggressor unpunished - key motivator for enactment

• Modern media intensifies two levers

• Scale and repetition

• Interactivity

• Reliable correlation between exposure and aggression (small effects)

Cognitive Development

Piaget

• Bandura showed what children copy

• Piaget asks how they think about rules

• Moral judgment is a by-product of broader cognitive change

• Egocentrism → perspective-taking – 2 stages

• Heteronomous (4- 8 years) - Moral Realism

  • Young children have limited perspective-taking

  • Rules are fixed properties of the world, handed down by authority

  • Rule-breaking automatically brings punishment

  • Focus is on consequences not intent – cups example

• Autonomous (>8 – adult) – Moral Relativism

  • Schooling & peer interaction leads to perspective-taking

  • Rules are social contracts shaped by mutual agreement

  • Rules can change to serve group goals

  • Reciprocity & fairness emerge - punishments should fit motive

  • Intent, not just outcome, become important – cups example

Kohlberg

• Clear problem with Piaget – 4-8 and 8-adult

  • Finer grained shifts through adolescence & adulthood

  • Also note that not all adults the same – can reach different stages

  • Method: 84 Chicago boys (5 – 25 yrs) → Moral-Judgment Interview (6 dilemmas, 2-hour tapes) → retested every 3-4 yrs for 20 yrs

  • Example – Joe and the camp money

  • About the reasoning NOT the answers to the dilemmas

Pre-conventional — Childhood

1. Morality is externally controlled; obedience; someone else’s law

2. Self-interest with fairness

Conventional — Mid teens; late teens/early 20s

1. Interpersonal relationships; social roles and expectations; approval of others

2. Broader society; societal expectations

Post-conventional — Modest rise in adulthood; <5% adults

1. Social contract; fair procedures for interpreting and changing the law; fundamental rights

2. Personal conscience – ‘it’s just the right thing to do’

Parenting

• Imitation and cognitive development do not happen in a vacuum - daily parent-child exchanges supply:

  • moral models

  • opportunities for reason-giving dialogue

  • consequences that calibrate self-regulation

  • Baumrind’s two axes, four parenting styles

• Authoritative – the Gold Standard

  • Combines high control with high warmth.

  • Uses induction: “How did taking the toy make your friend feel?”

  • Predicts fastest shift from Kohlberg Stage 2 → 3/4

  • Higher prosocial behaviour scores.

• Authoritarian – rules without reasons

  • High control, low warmth

  • Relies on power assertion (yelling, spanking).

  • Children stay focused on reward–punishment logic (Stage 1/2)

  • Show more externalising problems - breaking rules, disrupting class, becoming aggressive

• Indulgent & Neglectful – under-socialized

  • Low control; moral scripts rarely challenged or explained.

  • Linked to poorer perspective-taking, weaker obligation to reciprocal fairness.

  • Behaviour often impulsive.

What Shapes Moral Development?

1. Social Learning – we absorb scripts (Bandura)

2. Cognitive Development – we re-organise scripts (Piaget → Kohlberg)

3. Parenting & Culture – context accelerates or stalls reasoning

• Interaction of acquisition ✕ reconstruction ✕ social scaffolding

• Imitation of smiles, distress

• Early childhood: rules = fixed (Heteronomous)

• Middle childhood: intent matters, peer rule-making

• Adolescence: conventional concerns (belonging, social order)

• Emerging adulthood: social-contract reasoning for some

• Minority reach “universal principles” frame

• Progression is typical but not automatic—needs challenge + dialogue

Practical Implications

• Parents & Educators

  • Model the behaviour you hope to see

  • Pair rules with reasons (induction)

  • Facilitate perspective-taking debates

• Policy & Media

  • Design prosocial content; limit rewarded violence

  • Use co-viewing + discussion to blunt imitation

• Striving to deepen moral reasoning is valuable, but “reaching Stage 6” shouldn’t be a blanket benchmark.

• A more realistic and healthy aim is to:

1. Reach at least a solid Stage 4–5 (respect for laws and the ability to question them),

2. Blend in care, empathy, and cultural humility, and

3. Translate principles into action appropriate to each context.

1.Morality is externally controlled; obedience; someone else’s law

2.Self-interest with fairness

3.Interpersonal relationships; social roles and expectations; approval of others

4.Broader society; societal expectations

5.Social contract; fair procedures for interpreting and changing the law; fundamental rights

6.Personal conscience – ‘it’s just the right thing to do’

Social Development

Newborn Preferences

Adults and Social Skills

• Adults can lack tact or awareness of social norms, leading to discomfort in social situations.

• They may be oblivious to how their actions affect others.

Children and Social Development

• Young children also display apparent lack of empathy or tact, like commenting on hair loss or aging.

• This is generally forgiven, as it's recognised they’re still learning social skills.

How Do We Learn Social Skills?

• Children move from self-centred thinking to considering others' views.

• This allows for harmonious social living.

Infant Preferences and Social Learning

• Newborns have built-in preferences that guide learning.

• Prefer faces, important for social interactions (Goren et al., 1975).

• Also prefer human speech and maternal language sounds, aiding connection and fitting into their community.

Goren et al. (1975) Study

• Infants preferred looking at a face-like schematic over scrambled faces.

• Showed stronger preference for scrambled face over blank face.

Emotional Sensitivity in Infants

• Within six months, infants show sensitivity to emotional cues.

• Field et al. (1982): Infants as young as 36 hours can differentiate happy and sad expressions.

• Around five months, infants prefer matched emotional sounds and visuals (Walker-Andrews, 1997).

Visual-Acoustic Emotional Matching

• Infants better match sounds and expressions for familiar people (e.g., mother).

• Ability to generalise this matching improves across first year.

Social Smile Development

• Initial grins may be due to basic comfort.

• By three months: Social smiles in response to facial cues emerge.

• By six months: Infants show more positive reactions to familiar people (e.g., mother).

Contagious Crying and Empathy

• Young infants (3–6 months) may cry when seeing another infant cry.

• Two perspectives:

  • Basic empathy (Hoffman, 2000; Simner, 1971).

  • Hyper-reactivity (Davidov et al., 2013).

Still Face Experiment (Tronick et al., 1978)

• Phase 1: Mother and infant in happy play.

• Phase 2: Mother adopts neutral “still face”; infant distressed, tries to regain attention.

• Phase 3: Mother returns to positive expressions; infant re-engages happily.

• Shows infants actively participate in social interactions.

Infant Learning and Development (6–18 Months)

• Infants become increasingly active learners between 6–18 months.

• Joint attention emerges as infants seek to share focus with others, using:

  • Gaze: To direct attention.

  • Pointing: Important for learning object names.

• Social referencing develops at 10–12 months.

  • Infants look to caregivers (especially mothers) to gauge how to react.

  • Visual cliff paradigm shows how infants rely on mother’s cues to assess safety.

Visual Cliff Paradigm

• Tests depth perception by creating an apparent drop-off.

• Infants hesitate to cross when they perceive danger, especially if mother shows fear.

Social Referencing Beyond the Lab

• Infants also check caregiver’s reaction in everyday situations (e.g., at parks, stairs).

• Caregiver’s expressions guide infant behaviour and risk assessment.

Scaffolding Mental State Understanding

• Scaffolding: Caregiver supports infant’s learning by discussing slightly challenging concepts.

• Mental states: Abstract concepts like desire, thoughts, beliefs, knowledge.

• Mothers often focus on desires first (e.g., "Do you want that apple?").

• Labelling infant’s desires helps them link internal feelings with words.

• Infants must first understand their own desires before understanding others'.

Sense of Self Development

• Around 18 months, infants begin to recognise themselves and develop a sense of self.

• Mirror self-recognition test:

  • Sticker or marker on infant’s head/nose.

  • Infant reaching for the sticker on themselves (not the mirror) suggests self-recognition.

• Amsterdam (1972): Most 24-month-olds pass the mirror test.

• Recognition development:

  • Photographs: Around 2 years (Lewis & Brooks-Gunn, 1979).

  • Videos: Around 3 years (Suddendorf et al., 2007).

• Infants update their self-image quickly if appearance changes (Nielsen, Suddendorf & Slaughter, 2006).

Mirror Test Extensions

• Experiments with sweatpants show infants adjust self-recognition based on updated self-image.

Talking About Mental States

• Around 18 months:

  • Infants use simple phrases about desires and perceptions (e.g., "Want cake," "See doggie").

• Around 30 months (2.5 years):

  • Begin to discuss thoughts (e.g., "I think cake is yummy").

Understanding Others’ Mental States

• Around 18 months, infants start to grasp that others’ desires can differ from their own.

• Repacholi & Gopnik (1997) experiment:

  • Infants offered experimenter broccoli if she preferred it, even if they preferred crackers.

  • Demonstrates early understanding that others have different desires.

Mother’s Role in Expanding Understanding

• Early focus: Mother talks about infant’s own desires.

• Later (18–36 months): Mother discusses thoughts/beliefs, including those of others.

• Example: Moving from “You want…” to “Daniel thinks…” to help infants see self/other differences.

Early Development of Prosocial Behaviour

Importance of Prosocial Behaviour

• Prosocial behaviour is essential for maintaining a functional society.

• Lack of helping or sharing would lead to societal breakdown.

Helping Behaviour

• Emerges around 14 months of age.

• Infants begin by helping adults complete tasks (e.g., handing over dropped pegs, opening cupboard doors).

• Some researchers argue infants understand others’ needs and mental states.

• Others suggest infants’ helping may be due to simple action–outcome associations.

Sharing Behaviour

• Begins at around 18 months.

• Early sharing typically requires explicit prompting (e.g., experimenter says, "Can you share with me?").

• By 3.5–4 years old, children start to share spontaneously without prompting, using subtle cues (e.g., experimenter says, "Oh!", indicating they have only one block).

Comforting Behaviour

• Comforting emerges around 24 months.

• Hardest prosocial behaviour for children to develop.

• Early comforting is prompted by explicit cues from adults (e.g., “Is there anything you can do for me?”).

• Comforting requires understanding abstract internal states like pain or sorrow, which are not visually obvious.

• Comforting behaviour continues to develop into the early school years.

Theory of Mind Development

Concept and Importance

• Theory of mind: ability to understand others’ mental states and predict behaviour.

• Mental states include: desires (“I want”), perceptions (“I see”), thoughts (“I think”), knowledge (“I know”), beliefs (“I believe”).

• Abstract nature of these concepts explains why children take until ~4–5 years to fully develop theory of mind.

Language as an Indicator

• Around age 3, children start using contrastives (e.g., “I like princesses, but my brother doesn’t”).

• Indicates emerging understanding of differing mental states.

Visual Perspective Taking

• Test involves child and puppet separated by mountains; child must judge if puppet can see an object.

• 3-year-olds assume others see what they see.

• 4-year-olds understand that others have different visual perspectives.

• Example: children’s hide-and-seek behaviour — 3-year-olds hide by covering their own eyes, assuming others can’t see them.

Appearance-Reality Task

• Tests if children understand that others’ knowledge might differ.

• Example: Band-Aid box containing markers — young children forget others wouldn’t know about the unexpected contents.

• By ~4–5 years, children understand that others’ knowledge is based on different experiences.

False Belief Test

• Wimmer & Perner (1983): Sally-Anne task.

• 42-month-olds fail to understand that Sally’s belief about the marble’s location is false.

• 52-month-olds understand Sally will look where she last saw the marble (basket), despite it being moved.

• Cultural variations in materials used (e.g., nuts instead of marbles), but similar timeline across cultures (3–6 years).

Theory of Mind in School Context

Social Dynamics

• Children who pass false belief test earlier are more popular and prosocial.

• Early theory of mind linked to helping, sharing, and comforting others.

Downsides

• Developed theory of mind can also be used for manipulation and bullying.

• These children may also be more sensitive to teacher criticism.

Autism Spectrum Disorder and Theory of Mind

Struggles with Development

• Children with autism show reluctance for eye contact and social interaction.

• Simon Baron-Cohen et al. (1985) study: compared typically developing children, those with Down Syndrome, and children with autism on false belief test.

• Results: ~85% of typically developing and Down Syndrome children pass; only ~20% of children with autism pass.

• Highlights link between theory of mind deficits and social difficulties in autism.

Attachment

The Lifelong Bond of Attachment

• Attachment is a lifelong affectionate bond developed early in life, usually between infants and their mothers.

• Babies show clear preferences for their primary caregiver, typically the mother, especially when they are distressed.

• The first relationship forms very early, within the first several months of life.

The Early View: Dependency Theory

• Freud’s Dependency Theory proposed that babies love their mothers because she satisfies their biological needs.

• This theory described babies as driven by biological states of need and relief: hunger, cold, discomfort.

• Babies associated their mother with relief and satisfaction of these needs, leading to affection and preference for her.

• Dependency Theory influenced social policy, including the creation and management of orphanages.

Criticism of Dependency Theory

• Critics pointed out that if love was just about getting needs met, toddlers should prefer the pantry over their mother, which they do not.

• Dependency Theory was mockingly called “Cupboard Love Theory” because it ignored the emotional aspect of attachment.

Orphanages and Poor Outcomes

• Orphanage systems built on Dependency Theory showed poor outcomes: children raised in orphanages were less physically and psychologically healthy and did worse academically than those raised in families.

• Research comparing children in orphanages versus foster care showed something specific about the orphanage environment was harmful.

The Search for Alternatives: Ethology and Imprinting

• Ethologist Konrad Lorenz studied animal behaviour in its evolutionary context, observing strong parent-infant bonds in precocial birds (e.g., ducklings).

• Lorenz discovered imprinting: ducklings followed the first large moving object they saw after hatching, regardless of whether it was their mother or Lorenz himself.

• Imprinting showed a strong attachment with no connection to food, suggesting an alternative to Dependency Theory.

Harry Harlow’s Rhesus Monkey Studies

• In the 1960s, Harlow isolated baby rhesus macaques to study the importance of social bonds.

• Isolates were raised in different conditions:

  • Extreme isolates: no social contact, basic needs met.

  • Surrogate conditions: wire mothers with a bottle or soft cloth mothers without a bottle.

• Despite being fed by the wire surrogate, baby monkeys spent more time clinging to the soft cloth surrogate, showing a preference for comfort and contact over mere nourishment.

Harlow’s Experiments on Isolation in Monkeys

• Explored different types and durations of isolation

• Extreme isolates showed bizarre, unhealthy behavior (e.g., rocking, self-harm) despite biological needs being met

• Mannequin mothers didn’t satisfy comfort needs; only soft, squishy mothers were clung to

• Feeding mothers didn’t promote attachment if not soft

• Returning isolates to social groups didn’t help; they couldn’t respond to social interactions and became socially isolated

• Social deficits extended to mating and maternal behaviors, leading to neglect or abuse of their own babies

Attempts to Rehabilitate Isolates

• Juvenile monkeys were effective in helping isolates regain social behaviors

• Juveniles persisted in approaching isolates, gradually breaking through social barriers

• Over time, isolates learned social behaviors from these interactions

Bowlby and the Emergence of Attachment Theory

• Rejected Dependency Theory (which said attachment is based on food provision)

• Proposed that infants seek security, not just physical sustenance

• Attachment Behavioral System (ABS) is like a control system (e.g., thermostat)

• The ABS is activated when the baby is separated from the caregiver, leading to behaviors like crying and clinging

• Babies are driven by a need for proximity to their caregiver for safety and survival

Development and Timing of Attachment

• Babies develop preferences for caregiver’s voice, smell, and face early in life

• ABS becomes strong around nine months, especially with the ability to locomote

• Stranger anxiety emerges at this stage as babies prefer to stay close to their caregiver

• Critical period for attachment formation is in the first two to three years of life

Practical Implications and Critique

• Bowlby argued that failure to form attachments in this period leads to lifelong issues

• Harlow’s studies showed that even severe deprivation effects can be reversed, questioning the permanence of critical period claims

• Human adoption studies show early deprivation has profound effects but can be overcome (Cohen et al., 2008; Miller & Hendrie, 2000; Pomerleau et al., 2005)

Mary Ainsworth’s Contribution to Attachment Theory

• Added the idea of balance between security (attachment) and exploration (independence)

• Exploration occurs when the environment is safe; security-seeking when there is perceived danger

• Babies continuously shift between these motivations depending on the situation

Mary Ainsworth’s Strange Situation Test

Three Major Attachment Classifications

• Secure (B) Pattern

  • Most common; around 60% in Western cultures.

  • Babies use mother as secure base; explore toys readily.

  • Wary of strangers; upset when mother leaves.

  • Immediate bid for proximity upon mother’s return; quickly calm down and return to play.

• Anxious Avoidant (A) Pattern

  • Around 20% of infants.

  • Babies are “cool” throughout; explore toys immediately.

  • Show little distress when mother leaves; no re-approach when she returns.

  • Lack of proximity-seeking; avoidant behavior.

• Anxious Ambivalent (C) Pattern

  • Around 20% of infants.

  • Babies are clingy, hysterical; sometimes too distressed to complete the test.

  • Minimal exploration; extreme distress on separation.

  • On reunion, show ambivalence (e.g., approach then turn away or hit mother).

Maternal Sensitivity and Attachment

Secure (B) Babies’ Mothers

• More sensitive and responsive to babies’ needs.

• Feed on infant-centred schedule rather than rigid schedule.

• Immediate responses to crying; more face-to-face contact.

Anxious Avoidant (A) Babies’ Mothers

• Report disliking contact with babies.

• Leave babies alone more often; less interaction.

Anxious Ambivalent (C) Babies’ Mothers

• Inconsistent caregiving; shift between rigid and infant-centred feeding.

• Unpredictable responses; baby unsure of caregiver’s behaviour.

Ainsworth’s Theory of Attachment System

• Attachment system exists in all babies; environment shapes its expression.

• Secure (B): Confident that needs will be met; environment supports attachment.

• Avoidant (A): Learn to be undemanding; keep calm to ensure mother’s return.

• Ambivalent (C): Inconsistent caregiving creates insecurity and hysteria.

Cross-Cultural Considerations

Northern Europe (Grossmann et al., 1980)

• High proportion of anxious avoidant (A) babies.

• Cultural norm of fostering independence in babies who can sit up.

• Babies accustomed to being left alone; avoid crying to avoid being put to bed.

Japan (Takahashi, 1986)

• High proportion (32%) of anxious ambivalent (C) babies; none avoidant (A).

• Cultural practice of co-sleeping with mother; separation during test is traumatic.

• Babies show extreme distress when separated from mother.

Critiques and Broader Considerations

Cultural and Contextual Differences

• Ainsworth’s theory was mother-centric and culturally uniform.

• Rothbaum et al. (2000): Different cultural views on mother’s sensitivity and competence.

• Babies’ own characteristics matter (e.g., easily overstimulated babies need less face-to-face contact).

Lifelong Impact

• Early attachment patterns can influence relationships into adolescence and adulthood.

Cognitive Development

Developing Knowledge and Understanding in Children

Cognitive Development and Knowledge Construction

• Jean Piaget's Background

  • Swiss genetic epistemologist who studied how knowledge develops.

  • Early work focused on animals and mollusks.

  • Shifted to observing his own children’s development.

• Constructivist Theory

  • Children actively construct knowledge through exploration.

  • Knowledge built via manipulation of environment, not just instruction.

• Four Stages of Cognitive Development

  • Sensorimotor (birth–2 years)

  • Pre-operational (2–7 years)

  • Concrete operational (7–11 years)

  • Formal operational (11 years+)

  • Stages are sequential; no skipping.

• Schemas and Equilibration

  • Schemas: Basic units of knowledge guiding learning.

  • Disequilibrium: Conflict between schema and new experience.

  • Assimilation: Fitting new experiences into existing schemas.

  • Accommodation: Creating new schemas to handle new experiences.

Sensorimotor Stage (Birth–2 Years)

• Exploring the World

  • Infants use senses and motor skills to learn.

  • Initial exploration often accidental but becomes intentional over time.

• Development of Object Permanence

  • Understanding that objects continue to exist when unseen.

  • Emerges around 8–12 months; fully developed by 2 years.

  • Evidenced by ability to find hidden objects.

• Mental Representation

  • Infants form internal images of objects.

  • Deferred imitation (e.g., puppet task) shows memory and mental representation.

  • Emerges around 18–24 months, also seen in pretend play.

Pre-operational Stage (2–7 Years)

• Symbolic and Representational Activity

  • Growth in language and symbolic play.

  • Language as a key symbolic tool (words as stand-ins for objects).

  • Make-believe play develops further (e.g., using a banana as a phone).

• Challenges

  • Children struggle with coordinating multiple conflicting representations and understanding others’ perspectives.

Piaget’s Stages of Cognitive Development

Concrete Operational Stage (7–11 years)

• Children develop logical thinking.

• They can perform conservation tasks:

  • Conservation of number (e.g., coins) – easier to grasp.

  • Conservation of mass (e.g., clay).

  • Conservation of liquid (e.g., glasses).

  • Conservation of weight – harder to grasp, usually by 8–10 years.

• They understand reversibility (e.g., pouring water back makes it the same again).

• Logical thinking is limited to concrete information they can directly perceive.

• They can reason with directly visible objects (e.g., comparing line lengths A, B, and C).

• Struggle with abstract or hypothetical situations (e.g., who’s tallest if they can’t see them).

Formal Operational Stage (from 11 years)

• Children develop abstract and systematic thinking.

• Can think through hypothetical scenarios (e.g., who’s tallest without seeing).

• Can generate and test hypotheses scientifically (e.g., pendulum task, isolating variables).

Preceding Stages

• Sensorimotor stage: learning through action.

• Pre-operational stage: focused on appearance, not logical reasoning.

Critiques and Challenges to Piaget

Task Demands and Language Reliance

• Piaget’s tasks relied on children verbalising their reasoning.

• High language demand might underestimate some children’s abilities.

Earlier Object Permanence

• Piaget: gradual development 8–24 months.

• Baillargeon & DeVos (1991): object permanence evident by 3.5 months using violation of expectation paradigm.

Sociocultural Influences

• Piaget focused on independent exploration of the world.

• Ignored social and cultural effects (e.g., teachers, parents).

• Judith Kearins (1986): Indigenous Australian children outperformed non-Indigenous peers on spatial memory tasks.

• Kearins suggested this was due to cultural emphasis on spatial memory and land knowledge.

Formal Operational Stage Across Cultures

• Many adolescents in Western cultures fail formal operational tasks.

• Piaget may have based stages on highly educated samples, not representative of general population.

• Suggests formal operational thinking may not develop naturally and could need educational or societal support.

Language Development

Human Language Uniqueness

• No other animal has language abilities like humans, even gorillas with ~98% shared DNA.

• Koko the gorilla learned to sign words, but never developed complex language like a human child.

• Language is intrinsic to human beings, not just communication (e.g., spoken or sign).

Critical Periods

• Attachment: No clear critical period for attachment in humans; children can overcome early deprivation.

• Language: Lenneberg (1967) suggests a critical period exists, though exact characterization is unclear.

Language Development: Human-Specific

• Language acquisition begins at birth, not at first spoken word.

• Newborns prefer the language they will speak (e.g., Spanish babies prefer Spanish; Moon et al., 1993).

• Babies are sensitive to all phonetic distinctions across languages at birth.

Decline in Sensitivity

• As babies approach their first birthday, they lose sensitivity to sounds not in their language.

• Example: Spanish babies hear “b” and “v” differences initially, but this fades if not relevant to their language.

Infant-Directed Speech (Motherese)

• Characteristics: slow, repetitive, with high/low intonations.

• Babies prefer it and it helps them find word boundaries (Cooper & Aslin, 1990; Fernald, 1985).

• Example: repeated phrases “chubby cheeks” highlight important words.

Babbling

• Babies babble from birth, making all possible language sounds.

• By first birthday, babbling resembles language they will speak.

• Example: 10-month-old babbling in English-like patterns.

• Babies learning sign language babble with hands (Petitto & Marentette, 1991).

Pointing and Language

• Unique to humans: babies spontaneously point to share experiences or draw attention.

• Precedes first spoken word; same function as naming (Goodall, 1986; Leavens & Hopkins, 1999).

• No spontaneous pointing in wild non-human primates.

Two Views on Language Learning

Nature View (Innate Language Ability)

• Language capacity is coded in genes and manifested in the brain.

• Overregularisation (e.g., "blowed up") supports this view.

• Noam Chomsky (1960s) argued for an innate Language Acquisition Device.

• Developmental regularity worldwide (e.g., first word at ~12 months).

• Poverty of input: input is too limited for children to learn only through imitation and reinforcement.

• Jean Berko Gleason’s (1958) "wug" experiment suggests children create new word forms they have never heard.

Nurture View (Learned Language Ability)

• Language learned through association, imitation, and social shaping (Skinner, 1953).

• Early language input and environment heavily influence acquisition (Hart & Risley, 1995; Hoff, 2003).

• Language development rates vary with socio-economic status and input amount.

• No universal grammar found despite decades of search (Dabrowska, 2015).

Critical Period Hypothesis

Concept and Evidence

• Critical period: early age window for optimal language acquisition.

• Babies acquire language rapidly and effortlessly compared to adults.

• Immigrant children’s accent acquisition suggests critical period around 7–9 years old.

Case Study: Genie

• Genie isolated from early childhood; discovered at 13.

• Taught language after rescue by Susan Curtiss (1977).

• Acquired limited vocabulary, but persistent word order errors.

• Evidence suggests missed critical period hampers grammar acquisition.

• Confounding factors: extreme abuse and deprivation complicate conclusions.

Supporting Observations

• Deaf children of non-signing parents struggle with fluent sign language if exposed late (Mayberry & Eichen, 1991).

• Immigrants past critical period typically speak with an accent.

Debate Status

• No definitive answer—nature vs. nurture remains a debate.

• Genie’s case and others offer partial evidence for a critical period and innate language capacity.

Adolescence

Historical Complaints About Adolescents

Ancient Criticisms

• Hesiod (8th century BC): No hope for the future if youth remain frivolous

• Hesiod: All youth are reckless

• Hesiod: Youth disrespect elders, show impatience

• Shakespeare: Ages 16–23 are marked by misdeeds and lack of restraint

• Aristotle: Adolescents are driven by sexual desire and act without self-restraint

Recurring Concerns

• Society has long worried about adolescents: teen pregnancy, disrespect, impulsivity

• These complaints have been ongoing for centuries

Generational Cycle

• Each generation criticizes the next but ends up fine and repeats the cycle

Defining Adolescence

Chronological Definition

• Adolescence = Teenage years (13–19)

Biological Definition

• Starts at pre-pubertal height spurt

• Ends with full reproductive maturity (~15–18 years)

Sociological Definition

• From puberty onset to assuming adult responsibilities (e.g., leaving home, supporting self)

• Can last 10–15 years, especially if adult roles are delayed

Tasks of Adolescence

1. Navigating Physical Changes

• Adolescents must adapt to rapid changes in their bodies

• Puberty changes body size, shape, and function

• Initial marker: growth spurt (Tanner, Whitehouse, & Takaishi, 1966)

Growth Spurt Details

• Pre-puberty growth: ~6 cm/year

• During puberty:

  • Girls: ~8.5 cm/year

  • Boys: ~9 cm/year

• Rapid growth can cause discomfort (e.g., leg pain at night)

• Adolescents must learn to move in taller, newly proportioned bodies

Timing of Growth Spurts

• Girls start growth spurt ~11 years

• Boys start growth spurt ~13–14 years

• Girls often temporarily taller than boys during early adolescence

2. Establishing Adult Identity

• Adolescents must separate from their childhood and family roles

3. Surviving Adolescence

• Adjusting to changes and forming a sense of self is a challenge

• Despite awkwardness, everyone endures puberty’s discomfort

Early and Late Puberty in Boys

Immediate Consequences

• Early puberty boys

  • Greater self-assurance

  • More attractive and masculine

  • More popular

  • Increased substance use, delinquency, and psychological issues

• Late puberty boys

  • Socially awkward

  • Misbehave more in class

  • Show anxious behaviors

Later Consequences

• Early puberty boys

  • More domineering and responsible

  • High self-control but rigid and conforming

  • More advanced careers

  • Difficulty coping with stress and intimacy issues

  • Possibly linked to higher testosterone and social hierarchy lessons

• Late puberty boys

  • Good sense of humor, insight, and self-understanding

  • Good intimate relationships

  • Social hierarchy challenges in adolescence may benefit them later

Early and Late Puberty in Girls

Immediate Consequences

• Early puberty girls

  • Greater independence

  • Popular with boys

  • Poorer school performance

  • Increased delinquency, early sexual experiences, substance use, depression, and body image issues

• Late puberty girls

  • Maintain good grades

  • Start dating later

Later Consequences

• Early puberty girls

  • Difficult social relationships

  • Lower education levels and early school dropout

  • More mental health and substance use issues

• Late puberty girls

  • Complete higher education

  • Maintain good academic performance

Adolescents’ Desired Changes

Boys’ Desired Changes

• 47% want to change scholastic ability/achievements

• 23% want to change personality

• 14% want to change physical appearance

Girls’ Desired Changes

• 39% want to change personality

• 27% want to change scholastic ability

• 24% want to change physical appearance

Common Patterns

• Both groups focus on scholastic ability, personality, and physical appearance, but with different priorities

Body Dissatisfaction Study

Australian Adolescents Study (Maude et al., 1993)

• Sample: 606 girls, 315 boys, all high-schoolers

• Boys

  • 34%: ideal thinner

  • 33%: ideal same as own body

  • 34%: ideal fatter

• Girls

  • 70%: ideal thinner

  • 20%: ideal same

  • 7%: ideal fatter

• Girls more dissatisfied with bodies despite not directly stating it

Consequences of Body Dissatisfaction

• Adolescence: spike in body dissatisfaction (e.g., anorexia, bulimia, body dysmorphic disorder)

• Risk factors: media consumption (even 5 mins of exposure can impact), perfectionism, internalisation, stressful home environments

• Link to compulsive behaviors (e.g., compulsive exercise)

• Control in chaotic environments (e.g., divorce)

• Long-term consequences

  • High body satisfaction: higher self-esteem, better peer relationships

  • Low body satisfaction: higher risk of depression, eating disorders, exercise dependence, steroid use

Media and Body Image

• Media portrayals: thin female models, muscly or lean male models

• Photoshop creates unrealistic, unattainable body ideals

• Media idealisation shapes adolescents’ body image and mental health outcomes

• Ongoing debate about model body standards and adolescent well-being

Adolescent Risk-Taking and Sensation-Seeking

• Adolescents are known for engaging in extreme risk-taking and sensation-seeking.

• Rates of accidents, suicide, alcohol and substance use, violence, reckless behavior, eating disorders, and risky sexual activity all increase in adolescence.

• Surviving adolescence is particularly challenging despite peak physical health (strength, speed, reaction time, immune function, resistance to injury, rapid healing, and less severe hangovers).

• Adolescents' mortality rates increase 200–300% compared to childhood, primarily due to difficulty controlling behaviors and emotions.

Examples of Adolescent Risk-Taking

• Adolescents account for 36% of vehicle accidents despite being less than 20% of drivers.

• Incidents like Facebook-organized parties turning into riots demonstrate poor decision-making.

• Tombstoning (cliff diving from great heights) is an example of sensation-seeking behavior.

• Dangerous drinking practices include vodka eyeballing, beer bongs, and rapid binge-drinking games like beer pong and flip cup.

Understanding the Drivers of Adolescent Risk-Taking

• Education alone (e.g., anti-binge drinking campaigns) does not reduce risky behaviors, as shown in surveys (Wechsler et al., 2002).

• Adolescents do not lack awareness of risks—it's not an issue of knowing what’s dangerous.

• The adolescent brain’s development plays a significant role in risk-taking.

Brain Development and Risk-Taking

• Nucleus Accumbens:

  • Deep brain region driving motivation for rewards (food, sex, social accolades).

  • Develops early, giving adolescents strong urges to pursue rewards.

• Prefrontal Cortex:

  • Responsible for long-term planning, logical reasoning, and “mental stop signal” (“this could kill me” thinking).

  • Develops last, leaving adolescents with an “accelerator” but no “brake.”

• This imbalance contributes to increased risk-taking in adolescence and declines as they mature and gain adult responsibilities.

Synaptic Pruning in Adolescence

• Adolescents’ brains undergo synaptic pruning, which reorganizes connections for greater efficiency.

• Pruning eliminates unused pathways and strengthens frequently used ones (use it or lose it).

• Major pruning phases:

  • First at around two years old.

  • Second in adolescence, pruning up to 50% of connections.

• This process improves thinking speed and efficiency.

Potential Benefits of Late Prefrontal Cortex Development

• Unpruned connections support creativity and flexibility of thinking (Thompson-Schill, Ramscar & Chrysikou, 2009).

• Impulsivity and creativity may be evolutionary adaptations, fostering novel patterns and adaptability in the human brain.

• Although risky for individuals, this developmental timing is beneficial for human creativity as a species.