2. Learning goals 1. 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
3. 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
4. Nature VS nurture Influences of nature consists of genes Genes-the biochemical units of heredity that make up the chromosomes Passed down when you were conceived Nurture comes from the environment Environment-every nongenetic influence, from prenatal nutrition to the people and things around us
5. Genetics in brief Thinking critically: what do we know about the human genetic code and how it affects our thinking and behavior? Everyone has genetic code Each nucleus contains 46 chromosomes: Chromosomes: threadlike structures made of DNA molecules that contain the genes Each person received 23 chromosomes fro mother and father Chromosomes are composed of molecules called Deoxyribonucleic acid(DNA)
6. 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 nucleotides Largest chromosome has about 250 million nucleotides and the smalles t has about 50 million We all exhibit same traits nation wide(smiling, laughing…etc. Scientist have found snips in which differ from one person to person
7. Genes… Have even found variations in areas that should not exist. These variations are called mutations Mutations- 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
8. Nature and individual differences Thinking critically: How do twin studies and adoption studies help behavior geneticists study the influences of nature and nurte? SMARTS??? WHO IS SMARTER THAN WHO
9. tWiNs Identical twins: Twins who develop from a single fertilized egg that splits in two creating two genetically identical organisms.
10. 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
11. heritability heritability:-the degree to which traits are inherited Who 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 same Identical twin studies- if one is divorced chances of other is 5.5 times more likely. Fraternal is 1.6 times likely
12. Twin studies Helped us learn about heritability of certain traits Also shown us influence of environment Reunited twin studies Adioption studies Will the adopted person have similar traits as biological parents or adopted parents? Political and religious influences
13. Environment matters Thinking critically: how much do our parents, peers and culture influence us? For our brains to meet their developmental potential, early experience is critical Brain changes over time Peer and parent influences Cultural 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
