epigenetics
study of how the environment itself influences our genes
can genes be changed by the environment?
NO! genes themselves cannot be changed by environment, but proteins that turn gene activity on and off can be
- think setting on a dimmer switch
- these changes in gene expression can produce enduring changes in emotion, cognition, and behavior —> MAY be passed down !
domain-general view of the mind
an all purpose mind
- mind made up of mechanisms that support learning broadly, regardless of what is being learn; everything interacts
- e.g. associative learning, memory, executive functioning
- often goes with empiricism, doesn’t have to
domain-specific view of the mind
a modular mind (Swiss-army knife metaphor)
- the mind is made up of separated mechanisms that support learning within individual domains; don’t necessarily interact
- e.g. face-detection system, numerical reasoning
- often goes with nativism, but doesn’t have to
crib speech
toddlers talking to themselves —> suggests internally motivated to learn to speak
continuous development:
- change is uniform and gradual- quantitative differences
- everyone thinks/acts in basically the same ways, kids just know/ act less, or less-well
- continuity theorists
- if you look at crawling to walking every day, growth is quantitative
discontinuous development:
change can be rapid, with qualitatively different stages across lifespan
- baby is a diff sort of creature from a kid, who is a diff sort of creature from an adult
- think/act in fundamentally different ways
- e.g. hide-and-seek development
- stage theorists like Piaget, Freud and Kohlberg
- if you look at crawling to walking once per month, growth is qualitative
variation within and across cultures of developmental outcomes
poverty is major influence in developmental outcomes —> poor children do less well across the board
- have challenges, living in dangerous neighborhoods, food insecurity
- some are resilient despite challenges
- cultural diffs in beliefs/ practices
- childcare practices over time in Canada
- sleeping arrangements
- whether independence is valued in a culture
critical/sensitive periods
- critical period = time when development must occur fi it’s going to occur at all
- mother-newborn bonding in the first few minutes
- building trust in first few years
- language learning late in life is HARDER than when we’re younger
Romanian orphans
- communist policy beginning in 1960s in Romania to increase population, punishment for having <5 kids (contraception, abortions outlawed)
- huge number of abandoned infants warehoused in institutions
- life in institutions
- cleanliness and order prioritized
- children kept in cribs at all times except for washing
- caregivers constantly changing and instructed to touch children as little as possible
- no affection, no play
- outcomes:
- flattened heads, stunted physical growth
- severe motor deficit
- intellectual delays
- social immaturity
- international adoption after fall of communism —> from bad to great environment
results of Romanian orphans study
- children’s long-term outcomes depended on age at adoption
- those adopted <6 months , no different from British-born adoptees
- between 6 and 24 months, some long-lasting deficits
- > 24 months, severe and long-lasting deficits
- social developmental deficit particularly pronounced and persisted in adulthood
- deficits even when examining children with equal time in new homes
- timing of bad experience if confounded with overall time in orphanage
reliability (types of r)
can researchers obtain same results across multiple occasions?
- inter-rater reliability- different raters, same results?
- test-retest reliability- same kid, different time, same results?
validity (types of v)
are you measuring what you think you’re measuring?
- internal v: can effects observed be attributed to what you’re measuring/ your manipulation
- are they VALID measures of the contract? or is there some confound/alternative explanation?
- external/ecological v: are finding generalizable to people in general or just this sample? is this something that accurately reflects the real world or only the lab?
naturalistic observation pros v cons
observe individuals in their natural environment, not attempt to influence behaviors
pros
- see participants acting normally in real world events
- may observe important things you weren’t looking for
cons
- sought after behavior may never occur
- no control over environment
- experimenter effects always possible
- huge amounts of possible data
structured observations pros v cons
control the environment to attempt to draw out behavior of interest
- squabbling
pros
- behavior more likely to happen, extra stuff less likely
cons
- a bit unnatural,, less real world
correlational design pros v cons
measure two variables, determine relationship
- ex: prenatal drug exposure and language development
pros
- see direction and strength of relationship between variables
cons
- correlation doe not equal causation!
- direction-of-causation problem
- third-variable problem
- e.g. time spent reading and reading achievement; night lights and nearsightedness
- —> ONLY experimental designs determine causation
between v within subjects design
between has two groups: experimental groups and control group, groups compared
- design straightforward, can be sure groups are independent
- but, individual differences might make it harder to find an effect: less statistical power- need more subjects
within has one group: each subject gets both experimental items and control items, items compared
- accounts for individual differences! thus has more power, fewer subjects needed to find effects
- but, practice effects and other ways item could influence each other
quasi-experimental designs pros v cons
compare groups, but membership not randomly assigned
- often for practical or ethical reasons
- age, sex, race, culture, cochlear implants, SES
pros
- see important differences between groups
cons
- essentially, correlational designs
- need to ensure groups matched as closely as possible on other variables
- difficult to be sure of causality, as third variables may be in play
- choice of cochlear implants
