Developmental Psychology

Phylogeny

Evolution of species

Ontogeny

Evolution of individual organism (recapitulates phylogeny)

Strengths and limitations of cross-sectional designs in child development

Quick and easy to conduct BUT individual differences averages and may be affected by cohort effects

Strengths and limitations of longitudinal designs

Shows individual patterns, time consuming, expensive , high attrition rate and selective survivors

Strengths and limitations of micro-genetic experiments

Can reveal process of change in detail, not generalisable

What did plato suggest about child development

(Nativist) emphasised self-control and discipline, children born with innate knowledge

What did Aristotle suggest about child development

(Empiricist) knowledge comes from experience

John locke

Empiricist - children as a blank slate

Rosseau

Children should have maximum freedom

Synaptogenisis

Density of synaptic connections between neurons greatly increases before birth ( and many months after)

Rich learning environments lead to more synaptic connections

Habituation

Decrease in responsiveness to repeated stimulus reveals learning has occurred. Speed of habituation reflective of general processing

E.g. eyes widening at first but then yawning and becoming disinterested, sucking rate

Observational learning

Imitation behaviour or intention

Perceptual learning ( differentiation and affordances)

Using perceptual abilities to search for order and regularity

Differentiation - extraction of elements that are invariable from changing stimulation

Affordances - possibilities for action offered by objects and situations

Statistical learninf

Picking up information from the environment and forming associations with stimuli that appear in a statistically predictable pattern

What perspective does Piaget take & 4 traits of his theory

Constructionist - interaction between child and environment, children intrinsically motivated to learn

1. Constructionist

2. Stage theory

3. Invariant sequence

4. Universal

Sources of continuity in development

Accomodation - adapt current knowledge structures in response to new experiences in the world

Assimilation - people translate incoming information into a form they can understand

Equilibration - people balance assimilation and accomodation to create a stable understanding

Sources of discontinuity in development

Hierarchical stages, central properties - distinct qualitative stages with changes, broad acceptability, invariant sequence

What are Piaget’s 4 stages and what age do they occur

1. Sensorimotor stage - birth to 2 years

2. Pre-operational stage 2-7

3. Concrete operational stage 7-12

4. Formal operational stage 12+

Sensorimotor stage

Birth to 2 years

Infants get to know the world through sense and actions, born with reflexes.

Object permanence emerges at around 8 months, A-not-B task, start to form enduring mental represeshiwn through deferred imitation

Pre-operational stage

2-7

Toddlers and young children start to rely on internal representations of the word, based on language and mental imagery

Aquire symbolic representation- the use of one object to stand for another. Egocentrism - perceive the world only from their perspective. May make conservation errors

Concrete-operational stage

7-12

Begin to reason logically about the world, can solve conservation problems, thinking systematically remains limited.

Inheld & piaget’s pendulum problem = task to compare swing with different strings and weights - children below 12 do unsystematic and incorrect measurements

Formal operational stage

Can think abstractly and reason hypothetically, can imagine alternate worlds

Piaget believed this stage was not universal, instead depending on the environment

Limitations of piaget’s theory

Understates the contribution of the social world to cognitive development

Vague about the cognitive processes that give rise to children’s thinking and mechanisms that cause cognitive growth

Depicts infants thinking as more consistent than it is

Infants and young children more cognitively competent than Piaget recognised

Vygotsky’s sociocultural approach to child development

Children are social beings who gain skills from those they socialise with - focus on surrounding culture and emphasis on guided participation, more knowledgeable individuals organise activities in ways that allow less knowledgeable people to engage with them

Outline vygotskys 2 levels of mental functioning

• lower mental functioning - mental functions closely tied to biological processes - innate and involuntary e.g. memory, simple perception etc.

• Higher mental functioning - consciously controlled transformations of lower functions developed through cultural mediation (transmission of knowledge through social interactions), these allow children to learn cultural tools and eventually use these independently

Private/ego-centric speech

Vygotsky viewed this as the foundation for all higher cognitive processes - language and thought being intertwined

Helps guide behaviour during difficult tasks, gradually becomes quieter

Outline 3 stages of behaviour regulation

1. Children’s behaviour controlled by other people’s statements - parent/guardian instruction

2. Children’s behaviour is controlled by their own private speech - most prevalent between 4-6

3. Children’s behaviour is controlled by internalised private speech

Intersubjectivity

The mutual understanding that people share during communication

Joint attention

A process in which social partners intentionally focus on common reference

Social referencing

Tendency to look to social partners for guidance

Zone of proximal development

Range of what children can do without support and with optimal support

Social scaffolding

More competent children provide a temporary framework for children

Object knowledge

Understanding that objects have substance, maintain their identity when they change location, continue to exist out of sight

What did Piaget suggest about object knowledge

Object knowledge and permenance doesn’t develop until around 8 months - until then, infants will not search for an out of sight object - infants in A-not-B task will continue to look in location A even when they see it be put in location B

Factors affecting whether children make the A-not-B error

Number of hiding locations, length of delay, age of child, number of times hidden in location A

(However, the basic result is in no doubt as the task is highly replicable)

What is a new test for object permanence ? & example

Violation of expectancy procedures - infants more competent when tested via visual-attention measures, e.g. Baillargeon et al. Found infants as young as 3 ½ months look at an impossible event longer than a possible one.

Possible explanations for why infants show object permanence in VOE but not A-not-B tasks

Memory limitations - they remember where the item is hidden most often

Problems with inhibitory controls - overlearned

Competition between representational system and response system

Children’s physical knowledge

Knowledge of gravity begins during 1st year, infants look longer at objects yay violate expected motion trajectories - 7 month lids surprised to see a ball roll up a hill unaided

Outline infants understanding of intention

• if they see a person repeatedly reach for an object in the same place, their action is directed towards the object not the place

• Infants may attribute intentions and goals to inanimate entities as long as they behave like humans

• 12 month olds able to attribute dispositional states - e.g. ball trying to get up hill and be helped by triangle blocked by square, infants showed preference to helpful triangle

Conceptual knowledge

General ideas/understanding can be used to group together objects, events etc.

Catagory hierarchies - what are the 3 levels

Infants figure out how things are related by dividing them into categorical hierarchies

• very general (superordinate)

• Medium (the basic level)

• Very specific (subordinate)

Usually learn the characteristics of the basic level first because they share many characteristics, unlike superordinate

Make catagories from 3-4months

Outline how causal connections help babies learn categories

Babies 7m/o created toy planes and birds as members of different catagories despite looking alike

As they approach 2y/o they increasingly categorise objects on the basis of shape and function - understanding causal connections helps children learn and remember new categories

Knowledge of living things

Children between 4-10 believe plants & animals were created to serve specific purposes, like tools

• below 1; distinguish people and non-living but not living non-living

• Up to 5; difficulty understanding humans are animals

• 7-9; understand plants are living

What is children’s knowledge of heredity like?

Know physical characteristics passed on from parent to offspring

• have essentialism - think boys prefer cars as a result of ‘boyness’ rather than environmental influences (9-10)

• Understand growth is an internal process and plants and animals can heal, understand old age and illness can cause death

What’s the difference between sensation and Perception

• sensation - processing of external information in sense organs and brain

• perception - organising and interpreting external information

What is infant vision like?

Approaches adult visual discrimination by 8 months and adult acuity by 6 years

• can be measured by how long they look at striped pattern vs fully grey one as they have poor contrast sensitivity

Children have immature cone cells with limited colour visions can discriminate between vivid colours rather than pastels

Outline scanning and tracking

Scanning : 1 m/o can scan perimeters of shapes , 2 m/o scan interior and exterior of shapes

Tracking : newborn infants begin scanning the environment right away, cannot track moving objects until 2-3 months

How do infants perceive faces

• from 9 months, we struggle to distinguish monkey faces, but 6 m/os can

• drawn to configurations with more elements in upper half than lower

• Infants prefer mothers face from 12 hrs of exposure

• Look at attractive faces and female faces longer

• Understand facial expressions at around 4-5 months

Object segregation

Young infants use common movements to perceive segregation

Depth perception

As young as 1 month old, infants blink defensively at an object that seems to be heading towards them

At 6-7 months they become sensitive to monocular cues

Before 19 months, infants treat pictures as what they symbolise

What is infant auditory perception like?

Hearing doesn’t approach adult levels until 5/6

Newborn infants turn towards sound - auditory localisation, perception of phonemes measured through infant sucking rate

Infant perception of music

Heart rate returned to normal mode quickly when played Brahm’s lullaby

Infants respond to rhythm and temporal organisation in music and show habituation to same tunes

Infant taste and smell

By 2 weeks, able to differentiate the smell of their mother, prefer the smell of breast milk regardless of whether or not they have formula (preference for sweetness too)

Intermodal perception

2 videos shown, infants prefer to watch images that correspond to the sounds they’re hearing

Define reflexes

Innate, fixed patterns of action that occur in response to particular stimulation, most fade within the first few months

Rooting

When baby’s cheek is stroked they will turn their head to the side of stimulation and open their mouth

Disappears around 3 weeks old

Sucking

Repeatedly when something is put in their mouth

Disappears at around 4 months old

Grasping reflexes

When a finger or object is pressed against a baby’s palm, the baby’s finger grasps around it

Disappears at around 4 months old

Babinski reflex

When bottom of baby’s foot is stroked, toes fan and curl

Disappears around 8-12 months

Stepping reflex

When held upright, will make rhythmic stepping movements, disappears at around 2 months

Moro reflex

When startled by something, baby throws arms back and arches back before bringing arms together as if holding something

Disappears at around 6 months

Dynamic systems approach & example

Emphasises many factors which contribute to neurological maturity, e.g. strength, posture, control, perceptual skills and motivation

E.g. stepping reflex thought to stop at 2 m/o just because of rapid weight increase - Thelen et al. Showed that babies still performed this reflex in a water tank

Impact of culture on development

Mothers in Mali believe it’s important to exercise infants to promote physical and motor development- does hasten motor development

When do infants develop reaching, manual dexterity & self locomotion

• reaching = 3-4 months

• Manual dexterity = ~7 months infants can sit independently, 9-12 months grasping affected by intention , 1 year sophisticated manual dexterity

• Self locomotion = 8 months begin to crawl, campaign for parents to stop lying babies on their front due to SIDs means that 1. Better view of the world means less motivation to roll over, 2. Less tummy time = less arm strength

Perception and action

Infants learn about affordances through our own actions

Specificity of motor learning

Begin walking independently at 13-14 months, infants don’t transfer learning from what they know about crawling down slopes to walking down them

Wariness of heights

Visual cliff paradigm; 6-14 m/o infants would not cross the deep side - understood depth . 1 ½ month olds perceive difference but show no fear, early crawlers avoid heights earlier

Interdependence in motor development.

Must perceive in order to move, move in order to perceive -development in one domain influences development in another

Scale errors

Toddlers treat miniature objects as if they were much larger

Why do children make scale errors?

• centration - focus on salient aspect of stimulus

• Dissociation between dorsal/ventral visual processing steams

• Faliure to inhibit an automatically afforded cation e.g. chairs afford sitting

Gametes

Produced through meosis, contains ½ genetic material of all other normal cells

Egg attracts sperm, ‘survival of the fittest’

Outline the Zygote & 3 stages of prenatal development

1. Germinal - conception to implantation (conception to 2nd week) during the germinal period, there is rapid cell division, cells doubling twice a day

2. Embryonic - implantation (3rd) to 8th week

3. Fetal - 9th week to birth

Outline the embryo

Implantation of cell mass becomes the embryo the rest of the cells develop into the support system

• has 3 layers , development of different systems or organs

• Cephalocaudal development, neural tube, U-shaped tube, differntiates into brain and spinal cord, folic acid

What is the support system of the embryo

Amniotic sac, umbilical cord : tube that contains the placenta - blood vessels between placenta and foetus

Placenta : exchange of minerals between foetus and mother - in ; oxygen, nutrients, minerals, anyibodies out; carbon dioxide, waste products

Outline fetal movement

• spontaneous movement from around 5 weeks

• Hiccups at 7 weeks

• Swallowing and foetal breathing at 10 weeks

• 12 weeks - most movements that will be present at birth have appeared

• 18-19 weeks - most arm movements are hand to mouth

Outline sensation and perception of foetuses

• amniotic fluid takes on tastes and odours from what parent has eaten

• Prefer sweeter tastes

• Contact w odour receptors through foetal breathing

• Heart rate changes when parent starts speaking, can distinguish between music and speech in 3rd trimester

Outline fetal learning

30 weeks, habituation to visual and auditory stimuli, evidence of learning & memory, increase in heart rate with parents voice compared to strangers

After birth they prefer parents voice and taste and smells experience through amniotic fluid

Teratogens

Environmental agents that have potential to cause harm during prenatal development

E.g. minimata disease; neurological symptoms caused by mercury poisoning in pregnant parents that becomes concentrated in fetus- thalidomide drug; caused limb deformities

Outline 3 factors that influence the severity of teratogen effects

Dose-response relation - amount of duration and exposure, multiple risks can have a cumulative effect

Sensitive periods - timing of potentially harmful agents, organs most vulnerable during formation of basic structures

Individual differences in genetic susceptibility- sleeper effect (apparent only later) e.g. DES drug caused cancer in offspring later in life

Name 4 other teratogens

Cigarettes - may lead to miscarriage or stillbirth

Alcohol - fetal alcohol syndrome

Maternal factors - significantly older or younger

Drugs - neonatal abstinence syndrome NAS, e,g. From opiods and cocaine

What’s the role of sleep in newborns

Need twice as much sleep as young adults

Role of REM:

• auto stimulation theory - brain stimulation during REM facilitates early development of the visual system

• jerking movements - myoclonic twitching during REM may give infants a choice to build a chance to build sensorimotor maps

Genotype

Genetic material an individual inherits

Gene expression

Information from a gene is used to produce protein, combination of genes switched in and off to contribute to phenotype - stem cells and specialised cells

Chromosome

Package of DNA

Gene

Basic unit of heredity, instructions for making proteins

Allele

Different versions of a gene, influence same trait but lead to different outcomes

Transmission of genetic material

Genetic material passed as chromosome via gametes - 46 chromosomes (23 pairs), 2 copies of each gene

Genetic diversity & individual differences

• random assortment of which member of each chromosome is used is determined by chance

• crossing over - members of a pair of chromosomes sometimes swap sections of DNA

• Mutation - a change in a section of DNA

How is gene expression determined

• dominant allele - expressed if present

• Recessive allele - not expressed if dominant is present

• Homozygous - 2 alleles of the same trait

• Heterozygous - 2 different alleles

What is the ‘male disadvantage’

Y chromosome smaller, contains less genes (1500 on x, 200 on y), recessive allele on x may not have y to override it and so inherited disorders may be more apparent in XY individuals e.g. colourblindness, duchenne muscular dystrophy, haemophilia

How do genes influence environment

Parents genes influence their own behaviour , children evoke different responses from others

Behaviour genetics

The closer 2 people are genetically (e.g. identical twins), the more likely they are to be in traits influenced by genetics

Quantative genetics research designs

Adoption studies - adopted children more like adopted or bio families

Adoptive twin studies

Family study

Twin studies (however, equal environments assumption is a confounding variable)

Molecular genetics research design

Examine specific DNA sequences to identify mechanisms that link genes & behaviour, permits the analysis of genetic influences in large samples of unrelated individuals, linking DNA segments with particular traits

Why, evolutionary, do humans need to form attachments?

Human infants are born less fully formed than other mammals

Outline Bowlby’s 4 stages of attachment

1. Pre attachment - birth to 6 weeks

2. Attachment in the making - 6 weeks to 6/8 months

3. Clear-cut attachment - 6/8 months to 1-2 years

4. Reciprocal relationships - 1-2 years onwards

Pre-attachment

Babies produce innate signals that bring others to their side and are comforted by interaction

Attachment in the making

Infants begin to respond preferentially to familiar people

Clear cut attachment

Actively seeks contact with their regular caregiver and protests when they depart

Reciprocal relationships

Take an active role in developing relationships