Developmental Psychology Flashcards
BEHAVIOUR GENETICS
Researchers try to understand how genetic and environmental factors combine to produce individual differences in behaviour (phenotype)
BEHAVIOUR GENETICS ESTIMATE
HERITABILITY
The degree to which variation in a particular trait (eg. IQ, shyness, schizophrenia) among individuals is due to genetic differences among those individual
Varies from 0 (no heritability) to 1 (complete heritability)
KINSHIP STUDIES
Use what we know about the degree of relatedness to work out the relative contribution of genes and environment to a particular phenotype
KINSHIP STUDIES MEASURE
Degree of relatedness
Probability of sharing genes among relative
TWIN STUDIES MONOZYGOTIC
essentially clones as they started as a single cell and then split into 2 fetuses
TWIN STUDIES DIZYGOTIC
develop when 2 sperms hook up with 2 eggs
TWIN STUDIES RESULTS
Same relatedness of DZ and sibling, only difference is siblings grow up in slightly different environments as they are born at different times but DZ’s grow up in the same environment)
Eg. HERITABILITY STATISTICS AUS
Physical characteristics (eg. 80% height) (lower in parts of the world malnutrition is a bigger problem) Mental illnesses (eg. 50% schizophrenia)
GENETIC AND ENVIRONMENT INTERACTIONS
Genes are not static
Environmental factions ‘turn them on’ (i.e gene expression)
Certain genes are expressed at certain times in response to certain environmental influences
STUDY EXAMPLE GENETICS AND ENVIRONMENT INTERACTIONS
Dunedin Multidisciplinary Study
1000 individuals followed from age 3
DNA findings related to environmental measures and psychopathology
MAOA gene and childhood maltreatment on conduct disorder
MAOA metabolises neurotransmitters in the brain; low activity associated with aggression in animals
RESULTS: Maltreatment is a risk factor for antisocial behaviour, BUT only in individuals with low MAOA activity
FADS2 gene and breastfeeding in IQ FADS2 GENE: Homozygous (CC or GG) Heterozygous (CG) RESULTS: Breastfeeding enhanced IQ, BUT only in children who are carriers of the C allele
NATURE VS NURTURE
combination of both
PRENATAL DEVELOPMENT OVERVIEW
Development that occurs between conception and birth
Begins in the fallopian tube when the sperm penetrated the egg and forms a zygote
Takes about 266 days (38 to 40 weeks OR 9ish months) for the one-celled zygote to become a fetus of 200 billion cells
THREE PERIODS OF PRENATAL DEVELOPMENT
Germinal
Embryonic
Fetal
GERMINAL PERIOD
From conception through implantation 14 days Zygote travels towards uterus Divides and forms blastocyst Contains 16 to 64 cells
EMBRYONIC PERIOD 4 WEEKS
5 WEEKS IN TOTAL
From 3rd week through to the 8th week
The blastocyst implants in the uterine wall
Layers of cells differentiate to become different parts of the body
Formation of major organs
Most risky time for teratogens
Neural tube closes at 3 weeks
○ Top of tube: brain (if this doesn’t happen neural tube defect - anencephaly - cortex doesn’t form - don’t survive more than a few hours)
○ Bottom of tube: spinal cord (neural tube defect - spina bifida, can be corrected sometimes but babies have locomotive problems)
Heart begins beating at 24 days
EMBRYONIC PERIOD 8 WEEKS
Internal organs form - but not functional yet
Fingers and toes separate
Facial structures fuse - cleft palate (end of embryonic period)
Women wait till the end of this period to say they are pregnant because if things go wrong in this period there’s no going back (miscarriage more common)
FETAL PERIOD up to 12 WEEKS
Lasts 7 months (from the 9th week until birth (38 week))
Organ systems begin to function; organism grows
A period of rapid growth and refinement of organ and brain systems
Fetus more responsive
Behaviour becomes increasingly regular and integrated
Fetuses become viable between 22-28 weeks
12 WEEKS
• Sexual differentiation
• Movement
FETAL PERIOD up to 18 WEEKS and 6 MONTHS till BIRTH
18 WEEKS
• Most growth in physical size during 4th month
• Practicing breathing movements so muscles are ready (but lungs aren’t functional yet)
6 MONTHS
• Fetus is capable of responding to light
• Able to hear sound
○ Sound level in the uterus is 75db
○ The mothers voice and heartbeat are best heard
• Limit of viability = 24 weeks (babies tend to not survive if they’re born before 24 weeks, because lungs aren’t sufficiently developed, don’t produce (which they would produce around 30-32 weeks) fluid called surfactant which keeps air pockets open when you breathe out)
7-9 MONTHS
• Fetus puts on weight in the form of fat just beneath the skin
DEFINE TERATOGENS
Any disease, drug, or other environmental agent that can harm a developing embryo or fetus
TERATOGEN EFFECT DEPENDS ON
Timing
○ Organ systems and brain are particularly susceptible during period of rapid development (first 8 weeks - first trimester)
Dose
Duration
EGS OF TERATOGENS
Cigarettes Alcohol (CAUSES FAS) Food poisoning dangers (i.e blue cheese, raw fish - salmonella) Illicit drugs i.e marijuana Medication that interacts with hormones Steroids
FAS DEFINE
FETAL ALCOHOL SYNDROME
A cluster of abnormalities that appear in the offspring of mothers who drink alcohol heavily during pregnancy
Microcephaly (small head), brain damage, life-long cognitive/learning delays Malformations of face • Epicanthal folds • Small eye openings • Flat midface • Upturned nose • Thin upper lip
Congenital heart disease
Joint anomalies
CRITICAL PERIOD DEFINE
A period of time during development when certain experiences are crucial for a particular feature of development to emerge
Eg. Imprinting in birds
SENSITIVE PERIOD DEFINE
A period of time during which experience is optimal for the development of a particular function, but it is not critical (can be made up for)
WAYS TO FIND HOW THE WORLD LOOKS TO AN INFANT
Let them show us via their behaviour
○ Visual scanning and fixation patterns
○ Habituation
○ Visual preferences
VISUAL SCANNING
What do infants look at?
What does that tell us about what they ‘see’?
Acuity (contrast) is less in 1 month old - meaning they prefer to look at high contrast lines and edges
1 month old - unable to disengage their focus
2 month old - distribute their attention (captures whole image)
HABITUATION
Telling difference between stimulus 1 and 2
Looking behaviour, heart rate, sucking rate
If shown the same image repeatedly sucking rate will go down (not interested) opposite is of different images
Similarly, length of each look
Sucking time goes up or heart rate is called dishabituation
VISUAL PREFERENCES
What do babies ‘prefer’ to look at?
What does that tell us about what they ‘see’
Babies prefer complex stimuli over plain stimuli (faces are what they prefer to look at the most)
Babies prefer real faces over faces which are scrambled
Prefer high contrast over low contrast (limit of acuity when they stop looking at contrast stripes as they get smaller than the plain grey - unable to differentiate) teller test
PERCEPTUAL DEVELOPMENT
Infants visual abilities are immature at birth
But improve rapidly over the first months of life
Early visual experience is important, however, infants can recover from deprivation if intervention occurs early enough
PERCEPTUAL DEVELOPMENT STUDY 1
PASCALIS 2005
TESTED: ability to discriminate faces of different species
Synaptic pruning - if the discriminatory faces aren’t used often (babies given a monkey story book and some babies aern’t) the ability to discriminate goes away/is pruned
PERCEPTUAL DEVELOPMENT STUDY 2
Ability to distinguish between faces of different races
3, 6 and 9 months
Were able to distinguish all 3 races in 3 months
only 2 races in 6 months
and only the race they were exposed to the most at 9 months
PERCEPTUAL DEVELOPMENT STUDY 3
What happens to visual development when early experience is not typical?
Problem: not ethical to deprive children of typical experience
Solution: animal models, clinical studies (‘experiments of nature’)
ANIMAL MODELS
Hubel and Weisel Kittens
○ Monocular deprivation Monocular deprivation (sewing one eye shut)
Carlson et al., (1987) monkeys
○ Binocular deprivation (both eyes sewed)
BOTH UNABLE TO USE EYE/EYES ONCE OPENED
ATTACHMENT
Relationship that infants form with primary caregiver
○ Want to be close to caregivers
○ Seek security from caregivers
○ Exhibit distress when caregivers are absent
ATTACHMENT STUDY
Infant rhesus monkeys Raised by inanimate mothers ○ Wire monkey with bottle ○ Soft monkey with no bottle Baby monkeys spent most of their time clinging to soft mother (Contact comfort)
ATTACHMENT THEORY
JOHN BOWLBY
○ Attachment in humans analogous to imprinting in animals; adaptive bond
○ Attachment figure becomes a safe base from which children can explore the world
○ Disruptions to attachment may have long term impacts on emotional and cognitive development
HOW DOES ATTACHMENT RELATIONSHIP DEVELOP
Newborns recognise their mother’s voice and show visual preferences for faces over objects
Infants recognise their mothers face within the first few days
Separation anxiety
○ First seen 6-7 months
○ Peaks early in the 2nd year
HOW DO WE MEASURE ATTACHMENT
Mum leaves room and baby is left with stranger, then mum comes back
The child’s response when their mother returns is coded
TYPES OF ATTACHMENT:
Secure attachment
§ Welcomes return, seeks closeness, comforted
Insecure-avoidant attachment
§ Not phased by mum leaving, ignores mother on return
Insecure-anxious attachment
§ Very upset on leaving, angry/rejecting on return, desired closeness but is difficult to sooth
Disorganised attachment
§ Behaviour is contradictory, eg. Approach mother but look away
CONSEQUENCEWS OF SOCIAL AND EMOTIONAL DEPRIVATION
PROBLEM: not ethical to deprive
SOLUTION: ‘experiments of nature’ orphans raised in institutions
FACTORS IN INSITUTIONS
High child: caregiver ration
Some basic needs met (eg. Nutrition/clothing)
Little one-to-one attention (even infants)
Lack of touch
Lack of responsiveness
CONSEQUENCES OF DEPRIVATION: INSTIUTIONS
Psycho-social dwarfism, stunted growth Intellectual delay Behaviour problems Inattention/hyperactivity Autism-like symptoms Disturbances of attachment
CAN SOCIAL AND EMOTIONAL DEPRIVATION BE MADE UP FOR LATER
depends on timing, first year is when most attachment is vital
STRANGER AT THE DOOR TASK
Stranger at the door task is a valid measure of indiscriminate behaviour; sensitive to group differences between institutionalised children and community controls
Intervention improved children’s performance, but the CAUG and FCG groups were not statistically significant
MEMORY DEVELOPMENT
PROBLEM: infants of different ages often tested on different tasks (need the same so you can compare properly)
○ Exception: operant conditioning (mobile task + consequences or reward) and train task(action + consequences or reward)
OPERANT CONDITIONING DEFINE + TASKS
Infants are very good at learning contingencies between their actions and consequences
TASKS:
Mobile Conjugate Reinforcement Task
Train Task
OPERANT CONDITIONING:
MOBILE CONJUGATE REINFORCEMENT TASK
Infants learn that their kicks produce movement in an overhead mobile (ribbon on foot and mobile)
OPERANT CONDITIONING:
TRAIN TASK
Infants learn that their lever presses produce movement in a train around a track
COGNITIVE DEVELOPMENT THEORY INTRO
JEAN PIAGET (1896-1980)
• Swiss philosopher/natural scientist
• Not actually a psychologist and didn’t test anything
• Interested in epistemology (theory of knowledge)
• Famous for studying his own children’s development and theorising about how children acquire knowledge (only 2 children)
COGNITIVE DEVELOPMENT THEORY INFO
Constructivist approach
§ Piaget thought that children construct knowledge by mixing their experiences with their own ideas
§ And updating knowledge based on integrating experiences
Done through: Schemas
§ Mental structure, or models that we create to represent, organise and interpret our experiences on how stuff works
How does knowledge change?
§ During development, infants/children adapt to meet the demands of the environment
□ Assimilation (not adaptive or adjusting of schema)
® Fitting reality into existing schemas
□ Accommodation (adaptive)
® Adjusting schemas to fit with reality
COGNITIVE DEVELOPMENT THEORY STAGES
- Sensorimotor stage (birth - 2 years)
2. Preoperational stage (age 2-7)
COGNITIVE DEVELOPMENT THEORY STAGE 1
Sensorimotor stage (birth - 2 years)
1) Infants ‘think’ with their hands, mouths and senses
2) Sensing and acting; little reasoning (not capable of cognition)
3) Egocentric - only see world from own perspective
4) Milestone
a) Object permanence (don’t have this in this stage but it develops - getting used to repetitive things)
b) Eg. Peek-a-boo
5) Late in the first year, infants begin to search for hidden objects, but their behaviour is inflexible (even if toy is hidden somewhere else in front of baby they will only look at what they’ve learned it’s been hidden by repetition before)
a) A not B error (Search for toy once covered)
COGNITIVE DEVELOPMENT THEORY STAGE 2
Preoperational stage (age 2-7)
1) Symbolic thought (connection between words and objects)
a) Can imagine without action (eg. Use a block to pretend talking on the phone with)
b) Still egocentric, problems with perspective taking
i) Eg. Three mountain problem
One. Put a doll on the other side of 3 mountains
Two. Put child on other side of mountains
Three. Ask child to point to a picture which represents the dolls view of the mountains
Four. Have a hard time doing this
2) Concentration
a) Fixate on a single feature of an object
i) Fail conservation tasks
One. EG 1. Asking which row of pennies have more in them
Two. Then spacing one row out more (they will say the spaced out one has more pennies) - conservation of space
Three. EG 2. having 2 glasses of water
Four. Pouring one glass of water into another longer glass so the water line is higher than the other glasses
Five. Will say the longer glass has more water (conservation of height)
ii) Fail dimensional card sorting tasks
One. EG 1. card sorting according to colour (blue and red)
Two. Change the task to shapes (eg. Blue flower, but the child puts it in the blue box not in the red flower box even though they are no longer playing the colour game)
CRITICISMS OF COGNITIVE DEVELOPMENT THEORY
Children are at a particular ‘stage’
□ Problem - thinking can be domain specific
® Conservation number earlier than mass a volume
§ Theory underestimates infants and young children
□ New methods (i.e. looking time) show evidence of object permanence much earlier
□ Dissociations between children’s knowledge and action (i.e. card sorting)
not much evidence for Piaget’s stages
