3c Ap psych

fraternal twins are also called

dizygotic two zygotes

active gene

dominant environmental events "turn on" genes when turned on, protein molecules provide the code to create the building blocks of physical development

why are children in the same family so different and why does their shared family environment have such little effect on children's personalities?

each sibling experiences unique peer influences and life events sibling relationships ricochet off each other, amplifying their differences siblings, despite sharing one half your genes have very different combinations of genes and may evoke very different kinds of parenting

what can turn on genes

environmental factors

heritability

extent to which variation among individuals can be attributed to their differing genes can be mathematically estimated using twin and adoption if heritability of intelligence is 50% it means genetic influence explains 50% of observed variations among people negative/inverse correlation between enviro and heritability

in what two ways are identical twins more similar than fraternal

extroversion and neuroticism

how do fraternal twins develop

from two eggs fertilized individually by one sperm each

interaction

genes and experience rely on one another effect of one factor (environment)depends on another factor(heredity) environments trigger gene activity genetically influenced traits evoke significant responses in others misbehaving student evokes angry response in usually docile teacher as we age, we select environments more suited to our natures

if genes influence traits such as emotional instability might they also influence the social effects of such traits

genes have fifty percent influence on the social effects of traits

your traits are _____

genetic. height, size of face, hair color, eye color. complex traits such as happiness, aggression, and intelligence are also genetic

genetic predispositions

genetically influenced traits (tall, short, funny) helps explain both shared human nature and human diversity

if genetic differences help explain individual diversity in traits such as aggressiveness can the same be said of group differences between men and women/ppl of different races

heritable individual differences may not imply heritable group differences putting people in a new social context will change their behavior

human genome

complete instructions for making an organism (all genetic material in chromosomes) shared genetic profile makes us humans and not chimpanzees or lamborghinis behavioral and biological similarities arise from our shared human genome

chromosomes

composed of a coiled chain of the molecule DNA, genetic master code for your body, threadlike dna structures that contain genes/46 chapters D

a scientist wants to differentiate between the influences of environment and heredity how would a behavior geneticist do this?

design 2 experiments.... 1. controls home environment while varying heredity 2. control heredity while varying environment

how do twins form?

develop from one egg and one sperm that splits in two

identical twins share ___ of genes

100%

how many "words"/genes do we have?

30000

fraternal twins share __ of all genes

50 percent like all siblings

basic principles of evolutionary psychology

-organisms varied offspring compete for survival -certain biological and behavioral variations raises an organism's reproductive and survival chances in their particular environment -offspring that survive are more likely to pass their genes to ensuing generations -therefore overtime population characteristics may change *when certain traits are selected by conferring a reproductive advantage to an individual or species-those traits, over time, will prevail

2 types of natural experiments behavior geneticists study

1 twins 2. adoption-> genetic and environmental relatives

environment

non genetic influences-prenatal nutrition to people and things around us

How do genes respond to major life stresses(trauma)

code for a protein controlling neurotransmitter involved in depression nature + nurture work together unless an infant has the gene that breaks down fatty acids breast feeding doesnt boost intelligence

genes can be ______ or _____

active/expressed or inactive

in traits such as ______ and _____ adoptees more similar to BIOLOGICAL parents

agreeableness and agression

what accounts for the slight personality and or physical differences between identical twins?

although identical twins have the same genes they don't always have the same number of copies of genes. helps explain why one twin may be more at risk for other illnesses

2nd darwinian revolution

application of evolutionary principles to psychology

genetic relatives

biological parents and siblings in traits such as agreeableness, adoptees are more similar to their bio-parents than to caregiving adopted parents a pair of adopted siblings or identical twins will especially during adolescence have more similar religious beliefs if reared together

how do twinning rates vary on a global scale

by race: caucasian twin rate 2x asian rate but 1/2 African rate. africa and asia most twins are identical western countries most twins fraternal. fraternal twins have increased with the use of fertility drugs.

genome

common sequence within human DNA the profile that makes us human rather than a pumpkin

how are heritability and environment negatively correlated

if all schools were equal quality, all families equally loving all neighborhoods equally healthy then heritability would be more influential because environment variability decreases, and vice versa.

does experience rather than genes account for twin similarity

in explaining individual differences genes matter. identical twins whose parents treat them the same were NOT more psychologically alike than twins not treated the same. therefore, genes account for psychological similarity (jim and jim)

how do molecular geneticists look for the implicated genes?

look for link between specific genes or chromosome segments and specific disorders 1. find families with disorder across several generations 2. take DNA samples from affected and unaffected families 3. look for differences in DNA

gender differences in sexuality

men more likely to initiate sexual activity we are predisposed to prefer whatever worked for our ancestors in their environments act in way leading to grandchildren women's approach to sex relational men recreational woman nurses and incubates one child men can spread their seed to many women men attracted to women with better chance of sending genes into future women's preference for men who will stick around shows capacity to support and protect. sexes are far more alike than different

whats another name for twins?

monozygotic (one zygote)

fitness

our ability to survive and reproduce in our environment

does natural selection explain our human tendencies?

our shared human traits were shaped by natural selection acting over the course of human evolution

how did we develop our shared human genome

over generations the genes of individuals not so disposed tended to be lost from the human gene pool as genes contribute to success continue to be selected behavioral tendencies and thinking and learning capacities emerged that prepared our ancestors to survive, reproduce, and pass their genes on to future generations.

how are humans of today biologically prepared for a world that no longer exists

predisposed to behave in ways that promoted our ancestors surviving and reproducing we love the taste of sweets and fats--> once hard to come by prepared ancestors for surviving famines our natural dispositions are more mismatched with today's junk food environment

genes are self regulating

rather than acting as "blue prints" w/the same result no matter the context, genes REACT --. therefore, people with identical genes but different experiences have similar but not identical minds

molecular genetics

seeks to identify specific genes influencing behavior trying to find genius influencing normal human traits body weight, sexual orientation, extraversion and explore mechanisms controlling gene expression looking for links between certain genes/chromosome segments and specific disorders

genes help us to adapt how?

self regulating

what has been noted about separated identical twins versus ones raised together?

separated twins have somewhat less identical personalities(characteristic patterns of thinking, feeling, and acting)

behavior geneticists

study our differences and weigh the effects and interplay of heredity and environment genetic and environmental roots of human differences

genes

the book of your life is 46 chapters 23 chapters about your mom and 23 chapters about your dad. the chapters are called "chromosomes" small segments of giant DNA molecules form the words of each chapter

what do genes provide when turned on

the code for creating protein molecules(building blocks of physical development)

environmental relatives

the environment shared by a family's children has virtually no discernable on their personalities. adoptive parents and siblings. ppl who grow up together, whether biologically related or not, do not much resemble one another in personality

how are molecular geneticists working with psychologists

to find genes that put people at risk for genetically influenced disorders such as learning disabilities depression schizophrenia and alcohol dependence

evolutionary psychologists

use natural selection focus on what makes us alike as a ppl. and to understand the roots of our behavior and mental processes