nature
biological endowment, genes, genetic inheritance, innate abilities
nurture
physical and social environments (home, womb, community, family etc.)
The Passive Child (Behaviorism)
children are passively shaped by their environments
The Active/ Passive Child
children have an active role in shaping the environment that will in turn shape them
reciprocal determinism
the environment affects the child, but the child's behavior also influences their environment
continuous development
view that development is a cumulative process: gradually improving on existing skills
discontinuous development
view that development takes place in unique stages, which happen at specific times or ages; rates spike in infancy and puberty
heterotypic continuity
Behavioral manifestations change but concept remains the same and is reliably connected to earlier development (ie: martin bites at 2, hits and screams at 6, gets in fist fights at 11, and threatens others w/ weapons at 17-- form of aggression changes, but aggression remains)
Issues with Continuity/ Discontinuity
General Trend vs Daily Fluctuation-- progress isn't always perfect
mechanisms of change
how does change occur; considered at three levels
reading example: behavioral mechanisms
kid chooses whether or not to practice reading
reading example: neural mechanisms
as kids become more experienced readers, the way their process words changes (sight words vs sounding out, phonetics)
reading example: genetic mechanisms
predisposition to be a more/ less effective reader, worse readers need more practice and scaffolding
Current vs Former Sociocultural Factors Example
more US children in childcare now than 50 years ago due to more women working and more economic disparity (hard to get by on one income)
Cross Cultural Comparisons: Sleeping
In US - young children encouraged to sleep alone by age one due to individualistic values Worldwide in collectivistic cultures, kids sleep with parents for longer periods of time due values of interdependence and harmony
Cross Cultural Comparisons: Research Choices
western cultures are more interest in researching identity and development of the self than are non-western cultures
universal aspects of development
physical growth, some language development, audio/visual development
variable aspects of development
socioeconomic status, genetics, parenting, access to food/ water/ shelters, different activities they seek out, major life experiences/ trauma
How can research promote children's well-being?
providing research based parental guidance, changing policy and law, informing the education sector, developing therapy techniques
Correlation vs Causation: Kids and TV Example
Kids who watch TV at mealtime eat far fewer fruits and vegetables than children who sit own to a quiet dinner table Interpretation 1: TV causes this Interpretation 2: parents are working
Correlation vs Causation: Blackouts and Birthrates
increase in birth rates in NYC hospitals was noted on the Monday and Tuesday exactly 9 months after the 1965 NYC blackout- by wednesday they were normal Higher birth rates every monday and tuesday- induced labor and c-sections scheduled then
7 research methods
Naturalistic observations Structured observations Clinical Interviews Structured interview/ tests/questionnaires Neurobiological methods Case study Ethnography
noise in data
Observer bias and social desirability bias Inaccuracies in parent/ teacher/ self report Effect on child's mood or other random factors on their behavior in the lab
reliability
the degree to which independent measurements of a given behavior are consistent; yields consistent results
interrater reliability
the amount of agreement in the observations of different raters who witness the same behavior (close= better); level of consistency between different observers
test-retest reliability
the degree of similarity/ level of consistency of a participant's performance on two or more occasions close together in time
validity
the degree to which a measure reflects what the researcher intended to measure
internal validity
the degree to which changes in the dependent variable are due to the manipulation of the independent variable
external validity
the degree to which results can be generalized beyond the particulars of the research
convergent validity
the extent to which the measure is related to other measures of the same construct (ie: the scores of two tests, one measuring self-esteem and the other measuring extroversion, are likely to be correlated—individuals scoring high in self-esteem are more likely to score high in extroversion)
discriminant validity
scores on the measure are not related to other measures that are theoretically different (ie: Calculating the correlation between scores on a math exam and knowledge of English literature-correlation should be zero!)
Correlation
the strength of association among variables (denoted by r)
what indicates strength of a correlational relationship?
the magnitude of the number (closer to +1 or -1= stronger relationship)
what indicates the direction of a correlational relationship
the sign of the number (- = one goes up, other goes down, += one goes up as the other does)
direction-of-causation problem
the concept that a correlation between two variables does not indicate which, if either, variable is the cause of the other
third variable problem example
Number of Ice cream sold and number of aggravated assaults look to be correlated- but the third variable is actually the weather
confounding variable
Some factor other than the variable of interest that, if not controlled by the experimenter, could explain the relationship between the variables of interest
How to control for confounding variables
A: Exclusion Criteria- issue: makes studies less generalizable (less external validity) B: Balance across groups C: Test as possible covariates
requirements for an experiment to provide evidence of causation
Two or more comparable groups
Participants w/i each group are presented with experiences that differ in only one way (independent variable)
The participants in two groups behave differently on a dependent variable (balanced group)
Provides evidence that the differing experiences caused differences in behavior
random assignment
assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups
experimental control
steps taken to ensure that other variables that could affect the dependent variable are equivalent in all groups
natural/quasi experiment
investigator measures the impact of some naturally occurring event that is assumed to affect people's lives
longitudinal study and limitations
same participants are studied repeatedly at different ages
selective attrition, cross generational problem which limits external validity
cross-sectional study and limitations
people of differing ages all studied at the same time
cohort effects; cannot tell us how individuals develop across time
sequential study and limitations
same groups of different-aged people studied repeatedly as they change ages (longitudinal and cross sectional), check for cohort effects
more time-consuming and expensive
microgenetic study and limitations
same participant studied repeatedly over a short period as they master a novel task; understanding the process of change/ mechanisms of change
intense experiences to stimulate change are atypical, limit external validity
SRCD Ethics Code (6 Points)
Doing no psychological of physical harm to children Obtaining informed consent and/or assent for children 7+ Preserving participant anonymity Discussing research results with parents or guardians Taking action to counteract unforeseen negative results that may arise Being honest with the child and explaining the findings of the research to the child in a way they can understand
Genotype
someone's unique sequence of DNA
Phenotype
the detectable expression of the genotype
Parent's Genotype- Child's Phenotype
Chromosomes (23 pairs)- parents give children their DNA ½ from each parent
Child's Genotype- Child's Phenotype
Many genes are never or only partially expressed ⅓ genes have two or more different forms (alleles) One allele from each parent (ie: hair color) polygenic inheritance
Child's Environment- Child's Phenotype
environment influences gene expression canalization (suppression of phenotypic variation) can occur (ie: motor development is highly canalized)
Child's Phenotype- Child's Environment
Evocative Gene-Environment Correlation: a child's genetic endowment elicits certain experiences or interactions with the world
Active Gene-Environment Correlation: Children select environments best suited to their phenotype; to their genetic predisposition
Parent's Phenotype- Child's Environment
Passive Gene-Environment Correlation: Environment in which child is raised is shaped by parent's genes, which are also part of the child's genetic endowment (Parent and child must be biologically related to each other)
Heritability
measure of the extent to which individual differences on a given trait in a specific population are attributable to genetic differences among those individuals (0<H<1)
Epigenesis
development resulting from ongoing, bidirectional exchanges between heredity and all levels of the environment
measures of socioeconomic status
Income/ Income-to-need ratio Parental education level Occupational prestige Neighborhood level Subjective Social Status Public Assistance Household Chaos Food Instability Cost of Living Generational Wealth
socioeconomic related risk factors
Nutrition, lead exposure, cognitive stimulation, parenting styles, hierarchy effects, chronic stress, trauma exposure, daycare/ school quality, parent psychiatric disorders, loss of caregivers/ disruptions in care, obesity, sleep disruptions
relationship between SES and race
Racially minoritized individuals are more likely to be low SES
iron deficiency and development
Iron deficiency in the first 3-5 years of life causes impaired cognitive and motor development; time sensitive- supplementation needed during the early years of rapid brain development
how many US children go to bed hungry?
1 in 4 (prepandemic)
food deserts
urban and rural low-income areas with limited access to affordable and nutritious foods; no supermarket w/i a census group
achievement gap
disparity on a number of educational measures between the performance of groups of students, especially groups defined by gender, race, ethnicity, ability, and socioeconomic status
what widens the achievement gap?
Rising Income Inequality The Rug Rat Race: affluent families today are investing much more of their money and time in early childhood enrichment than they did 40 years ago Kindergarten Readiness- privileged kids are getting ahead
Effects of early vs late childhood poverty
Early poverty is a stronger predictor of later cognitive achievement than poverty in middle or later childhood; Brain develops more rapidly at younger age, which can be a vulnerability for early childhood development in poverty stricken families
Neurocognitive disparities in language
Three y/o from professional families have more than double the vocabulary of those from families on welfare
Vocab Deficit Emerges Early (Fernald)
When you can't process language quickly enough you'll lose language input
Neurocognitive disparities in memory
impairment of declarative memory in children in low SES families
Neurocognitive disparities in executive functions
infants from low SES families are less advanced on A not B test (deals w/ object permanence). Executive function deficits persist into adulthood
zoo go/no go test
children in all economic domains responded quickly to the go signal, but kids in low SES families also responded to no-go signal
shape remembrance test and income
higher income was correlated with higher accuracy when remembering one time
which is true: social causation or social selection?
social causation
social causation
environmental risks associated with poverty hinder cognitive development
social selection
people end up in the social class that matches their IQ
SES Modifying Heritability of IQ: 7 y/o Twin Study
In high SES family, genes account for most variance in IQ (~60%) Kids have the means to reach their genetic potential
In low SES families, shared environmental influences account for more variance (~60%) genes have very little contribution Unstable environments limit kids from reaching their genetic potential
How is low SES associated with executive function
Early-emerging executive function deficits, which predict poorer academic achievement
Structural differences in neural regions implicated in executive function
Differences in how the brain responds during executive function tasks
How can low SES effect the brain
associated with slower brain waves in frontal lobe (hypoactivation)
simultaneous story study outcome
Lower SES children paid attention to the stories in BOTH ears, whereas higher SES children paid more attention to the target story
co-occuring adversity in mid-low income countries
Absolute poverty, stunted growth, macro and micronutrient deficiencies, environmental toxins, inadqutate cognitve stimulation
about how many kids under five don't attain their cognitive potential?
200+ million
study: adversity in pakistan
sindh province high child mortality, ~2/5 stunted by age 2 parenting intervention from ages 0-2 improved vocab and exec function by age 4, nutrition intervention did not
Brofenbrenner's Ecological Systems Theory
views the child as developing within a complex system of relationships affected by multiple levels of the surrounding environment
segregated neighborhood study
In the 100 largest metro areas in the US, almost 2/3 of white and asian american children live in high/ very high opp neighborhoods, in comparison to ⅔ of black, 58% of hispanic, and 53% of NA children living low or very low opp communities
healthcare inequity
-marginalized racial groups recieve poorer quality medical care
-low SES neighborhood hospitals have less access to qualitiy equipment and specialty doctors
-greater risk to child of early loss of loved ones due to healthcare inequities and incarceration
mechanisms through which racism harms child-wellbeing
interpersonal discrimination greater financial stress (mass) incarceration biological effects- toxic stress and unhealthy environments
methods to address systemic racism at source
individual family intervention
strengthen policies that proved economic support
place-based interventions
reduce cultural racism beginning in childhood
plasticity
the capacity of the brain to be affected by experience
Processes of Brain Development (***= prenatal)
Neurogenesis***
Neural Migration***
Neural Differentiation***
Neural Maturation
Synaptogenesis
Synaptic Pruning
Myelination
what happens in neuronal maturation?
Begins 15th prenatal week, but continues up to age two; axons thicken and elongate; arborization
what happens in synaptogenesis?
formation of synapses between neurons; most rapid during prenatal period and infancy, but continues through life
why do synaptic pruning and programmed cell death happen
overproduction of synapses
when does the visual cortex peak and mature?
peaks at one; matures at ten
when does the prefrontal cortex peak and mature
peaks at four; declining at ten; matures in adulthood
myelination
the formation of a fatty sheath around the axons of a neuron so signals travel faster
when are the visual and motor circuits myelinated?
infancy
which is myelinated first: broca's or wernicke's area?
wernicke's area (speech comprehension) myelinated first, ~6 months before broca's area (speech production)
what is the slowest maturing/ myelinating part of the brain
frontal cortex; goes through childhood
what can interfere with myelination?
fevers and nutritional deficiencies
Sensitive Periods in Brain Development
Window of time when the brain is extra sensitive to certain kinds of environmental inputs
experience-expectant processes
rely on species-typical experiences; often have sensitive periods (ie: human brains expect visual input, language, caregivers, etc.)
experience-dependent processes
Formation and pruning of synapses as the result of learning experiences unique to the individual's environment; occurs throughout the lifespan