Module 3:Nature and Nurture in psychology pg. 37

Learning goals1. define the nature-nurture issues and

explain the key issues of the field of behavior genetics

2. Name and describe the elements of the genetic code(chromosomes, DNA, genes)

3. Discuss how twin studies and adoption studies are used to learn about the inflouences of nature and nurture

4. Describe the research findings related to the environmental influences of early brain devleopment, parents, peers and our culture

How do our families, friedns, and the culture in which we live affect our whole field of study?

Behavior Genetics- the study of the effects of genes and environment on our behavior

Psychologist call this the nature-nurture issue

Nature VS nurtureInfluences of nature consists of genesGenes-the biochemical units of heredity

that make up the chromosomesPassed down when you were conceivedNurture comes from the environmentEnvironment-every nongenetic influence,

from prenatal nutrition to the people and things around us

Genetics in briefThinking critically: what do we know about the

human genetic code and how it affects our thinking and behavior?

Everyone has genetic codeEach nucleus contains 46 chromosomes: Chromosomes: threadlike structures made of

DNA molecules that contain the genesEach person received 23 chromosomes fro

mother and fatherChromosomes are composed of molecules called

Deoxyribonucleic acid(DNA)

Genetics continued….DNA-A complex molecule containing the genetic

information that makes up the chromosomes.Genes influence our behaviors Genes are distinguished by 4 letter

codes( A,T,C,G) called nucleotidesLargest chromosome has about 250 million

nucleotides and the smalles t has about 50 millionWe all exhibit same traits nation wide(smiling,

laughing…etc.Scientist have found snips in which differ from

one person to person

Genes…Have even found variations in areas that

should not exist.These variations are called mutationsMutations- random errors in gene

replication that lead to a change in the individual’s genetic code; the source of all genetic diversity.

Predisposition- predisposed to cancer= genetic mutation

Family health…. Diabetes, cancer, high BP

Nature and individual differencesThinking critically: How do twin studies and

adoption studies help behavior geneticists study the influences of nature and nurte?

SMARTS??? WHO IS SMARTER THAN WHO

tWiNsIdentical twins: Twins who develop from a

single fertilized egg that splits in two creating two genetically identical organisms.

Twins….Fraternal twins- twins who develop from 2

different fertilized eggs; they are genetically no more similar than any other 2 siblings, but they share a fetal environment

heritabilityheritability:-the degree to which traits are inheritedWho has more similarities identical or fraternal

twins?Intelligence testing on these areas:IF the intelligence levels of identical twins are

significantly more similar than the intelligence levels of fraternal twins, then we can say that genetics or nature is at work.

Genetic influences on personality follow the sameIdentical twin studies- if one is divorced chances of

other is 5.5 times more likely.Fraternal is 1.6 times likely

Twin studiesHelped us learn about heritability of certain

traitsAlso shown us influence of environmentReunited twin studiesAdioption studiesWill the adopted person have similar traits as

biological parents or adopted parents?Political and religious influences

Environment mattersThinking critically: how much do our parents, peers

and culture influence us?For our brains to meet their developmental potential,

early experience is criticalBrain changes over timePeer and parent influencesCultural influences:Culture- shared attitudes, beliefs, norms and

behaviors of a group communicated from one generation to the next

Norms-understood rules for accepted and expected behavior