Developmental psychology

What is developmental psychology

focusses on how people change throughout their lifespan → looks at the history, whether it is continuous or static and what causes the change

Child

• Dictionary definition is a person between birth and puberty.

• Legal definition is someone under 18

• Argument to be made that a person is not considered an adult until 25 (When the frontal lobe fully develops)

Prenatal

Conception to Birth

Infancy

birth to 18 months

early childhood

18 months to 6 years

Middle childhood

6-12 years

Adolescence

12-20 years

Young adulthood

20-45 years

Middle adulthood

45-60 years

Late adulthood

60 years to death

Ways to measure executive functioning

stroop task, go-no go task, dragon/bear task, card sorting task, looking, facial expressions, gestures and brain imaging

Cross sectional studies

involves collecting data from participants at a single point in time → Provides a snapshot of development at the specific age of the individuals when information was collected

longitudinal studies

Involves observing and collecting data from the same group of participants over an extended period.→ Examines changes or stability in behaviour, cognition, or other variables across time

Experimental studies

Involves manipulating one or more variables to observe their effect on development. → Usually involves multiple groups or multiple conditions so that the variable you want to manipulate can be tested.

observational studies

Often involves systematically observing and documenting behaviours → They could be conducted in natural settings or labs

Twin studies and adoption studies

• Twin studies → Compares the development of identical and/or fraternal twins to assess the contribution of genetics and environment

• Adoption studies → Involves examining children who were adopted and comparing them to both their biological and adoptive families and/or environments

Case studies

In-depth examination of a single individual → Offers detailed insights into unique developmental experiences or phenomena, often used in clinical psychology → Case studies typically involve one or a small number of participants → Good for depth of understanding → Limited in terms of empirical generalisation

Theories of development

ideas based on scientific evidence that attempts to explain and predict specific aspects of development.• e.g., Piaget’s theory of cognitive development

themes of development

• overarching concepts or principles that helps us to understand human development in psychology

• continuity or discontinuity, Nature/Nurture, Mechanisms of Development, Universality/Context-Specificity, Individual Differences

areas of developmental psychology

• physical changes → changes within the central nervous system → maturational & driven by the environment

• cognitive development → development of cognitive abilities → memory, thinking, perceiving and understanding the world → Understand the causes and mechanism that drive the development of cognitive abilities

• emotional development → The development of expressing, understanding and control of emotions → The development and consequences of emotional bonds → How the these bonds develop → What difference are these in these bonds and how do the affect later life?

• social development

Zygote stage

• day 0 → conception → ovum and sperm fuse

• day 6 → zygote is down fallopian tube and cells divide to form a sphere

• day 7-14 → zygote implants on uterus lining

embryonic stage

• begins at the end of implantation to 8th week

• week 3 → cells differentiate, neural tube begins to form and heart begins beating by the end of the week

• week 4 → heart is visible, blood vessels and lungs begin to develop and neural tube closes

• week 6 → limbs visible, nose and ears develop, facial structures and brain had divided into 3 main sections

• week 8 → all major organs present (except sex organs), basic structures of brain and central nervous system established and around 40g

foetus

• lasts ~32 weeks, continued development of organs and visibility starts around 23-24 weeks

• movement starts around 6 week, behaviour develop such as moving limbs, head, swallowing, breathing, hicupping and behaviour is cyclical

teratogens

• foreign agent that can cause abnormalities in the fetus and embryo

• eg cocaine, heroin, smoking, thalidomide, alcohol, rubella, chicken pox & HIV

Effect of cocaine

Reduces blood flow to the placenta and passes into the foetus bloodstream → Growth restriction, irritability, withdrawal symptoms, lower birth weight, increase in hyperactivity disorders

Effects of heroin

passes into foetus bloodstream → Lower birth weight, shrunken head circumference, cognitive impairments (e.g., spatial recognition, memory recall)

effects of smoking

Reduces oxygen intake and Constricts blood vessels in placenta → Lower birth weight, growth restriction, premature birth

Effects of thalidomide

Bypasses the embryonic defence system responsible for preventing toxic substances entering the embryo → 10 000 cases of thalidomide affected babies, 50% mortality rate and Severe birth defects in limbs, eyes, heart, and brain

Effects of alcohol

Enters through the placenta, Can lead to fetal alcohol syndrome, Limb and facial malformations, Growth restriction, Poor coordination, Hyperactivity, Kidney defects, Vision/hearing issues, Delayed development in speech & social skills, Distinctive facial abnormalities, ~10% of children born to alcoholics have FAS

Effects of rubella

enters through the placenta and causes deafness, cataracts and heart defects

Effects of chicken pox

If developed in first 20 weeks, can be fatal and causes Skin scarring, eye, brain, limb, and stomach abnormalities and If developed 48 hours before birth, risk of neonatal varicella

Effects of HIV

infection through the placenta and can cause facial deformities, HIV

When do ears develop?

Week 8 post-conception

What happens in terms of hearing around week 16?

• foetus perceives sound outside the womb through fluid-filled ears

• learns vocal rhythms and patterns → prepares them to perceive sounds of their native language

• also perceive internal sounds such as mothers heartbeat, air moving in and out of the lungs, stomach and blood

• the amniotic fluid filters sound immensely

• Only rhythm is perceived by the foetus → Words and lyrics are not likely heard (even if spoken/sung by the mom!)

What happens in terms of hearing around 25 weeks?

foetus can recognise and respond to mothers voice

What was the DeCasper & Spence (1986) study?

• Mothers instructed to read Dr. Seuss books out loud while pregnant

• After birth, newborns preferred listening to Dr. Seuss books compared to other non-Dr. Seuss books & Preferred mum’s voice compared to others → No preference for dad’s voice

• Currently, no evidence that reading to your fetus stimulates brain development

What happens around week 16 in terms of taste?

• foetuses can experience taste

• fed through umbilical cord directly from mothers stomach

• taste passes through amniotic fluid

Effect of smell for foetuses?

• Infants better able to detect odour in human sweat than adults (Loos et al., 2017)

• When presented with breast milk from unfamiliar woman v familiar formula, babies preferred breast milk (Marlier & Schaal, 2005)

• The scent of breast milk appears to have a calming, painkilling effect on newborns

Effects of sight on foetuses

• Week 7 – eyes start to develop

• Week 10 – eyelids develop and eyes stay closed

• Week 27 – eyes can open

• Week 31 – eyes can constrict/dilate in response to light

• Visual Acuity• 20/200 (normal adult vision 20/20)• Optimal focus fixed at 18-20 cm

Piaget’s perspective of children

• mini scientists

• children interact with their environment and learning is an active process

• they assimilate and accommodate new experiences into their schemas (building blocks of mental representations) → adaptation works upon schemas → eg sucking schema

• assimilation → process of taking new information or a new experience and fitting it into an already existing schema

• accommodation → process by which existing schemas are changed or new schemas are created in order to fir new information

What are the stages of development?

1. Sensorimotor → 0-24 months → infancy

2. Pre-operational → 2-7years → early childhood

3. Concrete operational → 7-11years → late childhood

4. Formal operative → 11years onward → adolescence and adulthood

Sensorimotor stage

• 0-1 months → exercise of innate reflexes

• 2-3months → development of schemas and beginning od coordination of schemas

• 4-8 months → outwards directed activity, differentiation of self from environment and reinforced behaviour

• 8-12 months → intentional means-end behaviour, learning about cause and effect and affecting their own environment

• 12-18 months → trial and error learning

• 18months → symbolic thought → actually hold stuff in the brain

Pre operational thinking stage

• 2-7yrs

• Development of symbolic function → e.g., language, symbolic play

• Beginning to represent actions mentally → But not in a coordinated, coherent way

• Egocentric→ Can’t distinguish & coordinate alternative viewpoints → Can consider only one perspective/dimension at a time → 3-Mountains Task

• Children have an “egocentric” view of the world

• Children cannot image what someone else might see

• Piaget concludes: children are naturally egocentric - they are unable to understand someone else’s view point during the pre-operational stage.

Concrete operational period

• Child can reason logically about changes and can coordinate different perspectives only with respect to“concrete” (real/observable) objects

• Children can demonstrate → Conservation• Reversibility• Understanding of others’ viewpoints → Better mental representations

Formal operational period

• 11+ years

• Logical thinking about abstract concepts and possibilities

• Ability to reason in purely symbolic terms

What is the object concept?

• initially → object not independent of infant

• 0-8months → Objects out of sight, out of mind and No search for covered objects

• 9-17months → Beginning to understand object permanence, Learn that objects can continue to exist, but with errors and A not B search failure

What is A not B error?

• Object is placed under Cloth A in front of infant → Infant can uncover the object underneath Cloth A →Then object is placed under Cloth B in front of infant → Infant is unable to uncover object underneath Cloth B

• The child has not grasped that the object is independent of their actions → Toy is still the “toy that is found on the left-hand side”.

What is conservative failure?

• Children under 7 years fail to conserve number equality

• A transformation in the objects demonstrates lack of ability• Child can’t understand that quantity is conserved → Focus on one dimension of the stimulus → Due to children lacking understanding of some basic logic principles of Reversibility and Conservation

• reversibility → the ability of a child to mentally undo or reverse an action or operation, understanding that objects or actions can be transformed back to their original state

• conservation → the understanding that certain properties of objects, such as their quantity, mass, volume, or number, remain the same despite changes in their outward appearance or arrangement

What are the critiques of the Piagetian theory?

• Possibly underestimates children’s abilities → perhaps his tests were not sensitive enough

• Vagueness about the process of change → how do children jump from stage to stage?

• Underestimates the role of social environment:• Tests were done on Western European children (this is where Piaget lived) → Vygotsky argued culture and social interaction were critical to development

• Learning may not happen in big stages! Maybe it’s gradual!

• Piaget could be limited in his test types → Perhaps further tests could determine infants’ true abilities → Infants may not be able to show us what they know

What is Vygotskys socialcultural theory?

• he believed that children are social learners rather than mini scientists → they are apprentices

• Children use existing knowledge from their experiences and from previous generations (“cultural tools”)

• Cognition is a product of social activity: Cognitive growth → results from children’s involvement in activities with others who are more skilled → They develop from lower to higher mental functions with others

What did Vygotsky say about ‘the zone’?

• we should teach in the “zone” between what a child can do alone and what a child can do with the help of someone more capable

• The difference between what the child can do independently (i.e., intramental pane) and what they can do with support from a more experienced other (i.e., intermental pane)

• Activity within the ZPD (zone of proximal development) is what leads to cognitive development

• The size of the ZPD is individual to the child and the domain

• Learning can be supported within the ZPD through scaffolding (Wood et al., 1976)

What is emotion?

a psychological state characterized by subjective feelings, physiological arousal, expressive behaviours, and cognitive appraisal, influencing how individuals perceive and respond to their environment.

What is the significance of discomfort/distress?

• Develops very early – within first 2 weeks

• Possible adaptive function of distress → Indicates to others the infant has basic needs that are unmet

What is the significance of sadness/anger?

• Around 2-3 months – anger and sadness expression start to differentiate

• Around 3 months – infant’s cries can be categorize

• Differentiations between expressions believed to be learned

• Based on feedback from environment in meeting the infant’s needs

What is the significance of wariness/fear?

• develops around 4 months

• Stranger wariness: Distress in presence of unfamiliar adult

• Involves signs of caution, hesitation, or distress in response to unfamiliar people or situations.

• May serve as a protective mechanism to prevent harm or danger by prompting infants to approach unfamiliar stimuli with caution.

What is the significance of a reflexive smile?

• around 4 weeks infants smile → often during sleep

• considered a reflexive smile → not intentionally smiling and not responding to a social situation

• begin to developing smiles in trimester 3 of pregnancy → exercising facial muscles

What is the significance of social smiles?

• around 6 weeks infants develop social smiles → bases on smiling with eye contact or attempting to make eye contact

• reflects the infants social awareness and ability to engage in reciprocal interactions with caregivers

• Facilitates caregiver-infant attachment and promotes social bonding

• infants smile because of familiar people and understanding that they can influence something

What is the significance of emotion regulation?

• ability to monitor, evaluate and modulate one’s emotional responses

• Development begins in infancy but limited → Reliance on caregiver soothing & Continues to develop throughout childhood / adolescence

What is the significance of self soothing?

• Emerges gradually – requires motor skills and learning → e.g., sucking on thumb or cuddling with a blanket

• Possible adaptive function of self-soothing → Foundation for emotional well-being and self-regulation

What is the significance of complex emotions?

• not typically seen in infants → e.g., guilt, jealousy, disappointment, pride, embarrassment

• Requires further development in multiple domains → e.g., cognitive – self-awareness, social – other awareness

What is the historical research of learning fear?

• 1920s → researchers wanted to study how babies learn fear

• started as a developmental study

• ‘little Albert’ → A baby under 1 year old & Recruited to study fear in infants

Method:

• Little Albert played with a white rat → not afraid

• A hammer makes a loud noise → afraid

• A hammer makes a loud noise while Little Albert is playing with the white rate → afraid

• The white rat alone (no noise) → afraid

Outcome:

• Infants can learn fear

• Fear can be generalised in infants

Criticism:

• Ethical issues with this experiment

• Learned about fear conditioning in general

• Gained little about infant emotional development specifically

What is attachment and what is its importance?

• the emotional bond formed between an infant and their primary caregiver(s), typically developing in the first year of life

• Suggests that infants seek proximity to their caregivers for protection and comfort.

• Emphasises the importance of early relationships in shaping later social and emotional functioning.

• Lasting psychological connectedness between human beings” (Bowlby, 1969)

• Freud → Child’s main drive is to feed → Mother source of food → Drive reduction

• Learning theory → Mother associated with food → “Cupboard Love”

Explain Harlow’s monkeys

• Tested hypothesis that food drive is basis of attachment

• Rhesus monkeys raised by two mothers → Wire mother & Cloth mother

• Half monkeys received food from wire mothers & Half from terry towelling mothers

• Harlow found → Monkeys preferred cloth mother in both cases → When frightened monkeys ran to cloth mother → Comfort not food basis of bond

What was Bowlby’s theory?

• Drive for “felt security”

• The development of the “Secure Base”

• Individual Differences in attachment

• Biologically rooted

• Signalling behaviours → Crying & Smiling

• Kewpie faces → Facial features commonly associated with infants → Large forehead, wide-spaced eyes, a small chin, and delicate facial features

What are learning theories?

focuses on how people get new behaviours or knowledge through experience and practice

What are social learning theories?

focuses on the influence of social interactions, observation and modelling in learning and social development

What is behaviourism?

• John B Watson (1878 – 1958)

• conducted research on child rearing and animal behaviour and advertising

• conducted ‘little Albert’ experiment → Conditioned response → Trained 9 month-old infant to fear anything furry and white

What is the social cognitive theory?

• Albert Bandura (1925-2021)

• Highly influential for the transition from behaviourism to cognitive psychology

• Emphasis on observation learning (Bandura, 1958)

• We don’t have to be directly rewarded, just observe it

• Children learn by following models → Bobo doll

What is the bobo doll experiment?

• 3 groups of pre-school children watched 3 different films of aggressive acts → Actor rewarded for acts, Actor punished for acts & No consequences

• the children are then placed in the room with the bobo doll

• Groups 1 and 3 produced most aggressive behaviours → Boys more than girls → All groups produced aggression if rewarded → Example of observational learning

• Limitations? → Ecological validity, Cumberbatch (1990) – novelty of the doll & Long term effects on children’s behaviour

What is the processing theory?

• Children interpret situations based on past experiences

• Including home environment and peer relations

• Evidence of Hostile Attribution Bias

• Becomes a self-fulfilling prophecy

• Evidence of Hostile Attribution Bias → Children tend to interpret ambiguous social cues as hostile or threatening, leading to aggressive responses.

• Creates a self-fulfilling prophecy → When children consistently interpret social cues as hostile and respond aggressively, it reinforces their belief that others are hostile

What are the 6 stages for problem solving?

1. Encode a problematic event

2. Interpret the social cues involved in it

3. Formulate a goal to resolve the incident

4. Generate strategies to achieve the goal

5. Evaluate the likely success of potential strategies

6. Enact a behaviour

What is gender?

• Biological characteristics

• Psychological characteristics

What are gender roles?

Expectations about behaviour patterns specific to each gender

What is the Sociobiological theory?

gender is purely biological (adaptive differences between sexes)

What is the cognitive developmental theory?

• children understand gender as cognition develops.

• Gender identity becomes stable over time (Kohlberg, 1966)

What is the social learning theory?

children learn gendered behaviours through observation, reward and punishment (Bandura, 1977)

What did Smith and Lloyd discover?

Adults' awareness of a child's gender influenced their behaviour and interactions → Highlights the role of social expectations in shaping children's experiences and opportunities for play.

What did LaDow discover?

• 125 picture books representing the work of 100 authors

Analysed:

• the percentage of males or females represented in the titles, main characters, illustrations

• roles and activities of adults

• activities of children

• Representation:

• 40% of the illustrations contained only male characters

• 11 % contained only female characters

• Roles:• Male characters depicted 81 different roles while female characters depicted only 17 different roles

What did Gooden and Gooden discover?

(2001):

• Females were listed as the main character 40% of the time and males in 39% of the titles analysed

• Male characters depicted 25 roles, whereas female characters depicted 14 role

• “Although most of the women’s roles were traditional ones (mother, grandmother, washerwoman, etc.), they were finally seen as doctors, chefs, and even milk vendors.”

Why are boys seen as more aggressive than girls?

• Boys 3 times more likely to be directly aggressive than girls (Card et al., 2008, findings from 148 studies)

• Why?

• Biology (Gat, 2010)

• Testosterone (Book et al., 2001)

• Genetic influences (Ferguson, 2010)

• Social influence (Berkowitz, 1993)

• Social learning

• Parent tolerance with male aggression

• Media influences

What is adolescence?

• a transitional stage between childhood and adulthood → marked by physical, psychological and social changes that are linked to puberty

• WHO definition ages 10-19 → broad and debated range

What is puberty?

• a biological process that leads to physical and hormonal changes preparing the body for sexual maturity and reproduction

• marked by: acceleration of physical growth, maturation of primary sex organs, differentiation of secondary sex characteristics and hormonal changes

• 8-14 in females and 9-15 in males → individual differences caused by genetic and environmental influences

• a sexually mature organism is one capable of procreation

What is synaptogenesis?

formation of new connections between neurons.

What is synaptic pruning?

regulatory elimination of these connections

How do signals pass over the synaptic gap?

signals are produced in the cell body (soma) and travel down axons as electrical signals → converted to chemical signals (neurotransmitters) to pass over the synaptic gap

Why is pruning in adolescents distinct?

It is based on learning and experiences. → “Use it or lose it” principal and makes brain more efficient at its chosen tasks.

What is gray matter?

cell bodies and unmyelinated axons → areas that are doing the thinking

What is white matter?

myelinated axons → cables connecting the different brain areas together

What is myelination?

myselin = fatty tissue that coats the outside of the axons, provides insulation and makes nerve impulses more efficient → info. travels 100x faster because of this

What is synaptic pruning?

first change after synaptic growth during fetal development → takes place more in the frontal lobes in adolescents → they also lose approx 3% of grey matter in frontal lobes

What are key executive functions?

Planning ahead, Inhibitory control, Switching between tasks & Updating the working memory → These are more advanced cognitive functions and thus mature later than more basic ones.

Why is sleep important?

• Sleep is needed to support the neurobiological changes during adolescence.

• A critical period of development (Larsen & Luna, 2018)

What are the affects of lack of sleep?

• Inconsistent sleep is associated with reduced frontal lobe gray matter thickness and poorer inhibitory control in adolescents

• Catching up on sleep on weekends was associated with increased white matter density and increased emotional control in adolescents (Guldner et al., 2023)

• Different effects for males vs. females! Sleep deprivation has a stronger effect on executive functioning in male adolescents than females (Kuula et al., 2015)

• Individual differences may exist! Sleep may be a protective factor in managing the adolescent critical period of brain development!

What are the stats. of adolescents getting ledd sleep?

• The percentage of adolescents sleeping more than 7 hours per night is less than 40% (Keyes et al., 2015)

• But when undisturbed, adolescents typically sleep over 9 hours per night (Carskadon, 2011)

What is the test for formal operational?

Third eye problem (“if you had a third eye, where would you put it?”) & Pendulum problem (“what governs the speed of an object swinging on a piece of string?”)

What was the Tamnes et al study?

Longitudinal study of individuals aged 8-22.• Completed working memory updating task and structural MRI twice, 2.5 years apart.• Findings: Improvement in memory updating associated with reduction in frontal lobe volume.

What causes the increase in emotional intensity?

Adolescents experience emotions more intensely due to heightened limbic system activity.

What causes the increase in emotional volatility?

Mood swings become more common due to hormonal fluctuations (testosterone, estrogen, cortisol)

What causes the heightened self-consciousness?

Adolescents become more aware of how they are perceived by peers, often leading to social anxiety

What is the imaginary audience effect?

many adolescents believe others are constantly watching and judging them, which can influence their behaviour (Elkind, 1967)