Unit IIIC Outline

I. Behavior Genetics: Predicting Individual Differences

-IF two super athletes

–Get married

–Have a kid

–The kid ends up being a super athlete

-Who gets credit?

-How much is nature?

-How much is nurture?

A. Genes: Our Codes for Life

-EVERY cell nucleus contains DNA

-46 Chromosomes

-23 from each parent

-Each chromosome is made up of DNA

-Small segments of DNA called Genes

-Active or Inactive

-96%-99.4% similarity

B. Twin and Adoption Studies

-Laboratory study would be unethical

-Twin studies allow us to study genetic similarities and environmental -differences and vice versa.

i. Identical Versus Fraternal Twins

-Identical twins-genetically identical (kind of)

-Same genes-different number of copies

-Most share a placenta, but some do not

-Fraternal twins-just siblings.  Genetically different

-Genes matter!!!  Divorce rate

ii. Separated Twins

-Jim Lewis and Jim Springer

-Oskar Stohr and Jack Yufe

-Anecdotal evidence?

-iii. Biological Versus Adoptive Relatives

-Genetic relatives (biological) vs environmental relatives (adoptive)

-In personality traits, adoptees are more like their parents (biological)

-Attitudes, values, manners, faith, and politics

C. Heritability

-Genetic influence explains 50% of the observed variation among people…

-NOT 50% genetic 50% environment…

i. Group Differences

-Heritable differences between individuals does not imply heritable group differences

-Peaceful Scandinavians or Ruthless Vikings

ii. Nature and Nurture

-Influence of adaptation (shoes or no shoes)

-Genes and environment go hand in hand (African butterfly)

-Alcoholism-Heritability doesn’t mean inevitability

D. Gene-Environment Interaction

-It takes two to tango…

-Neither genetics or experience solely account for behavior

E. The New Frontier: Molecular Genetics

-Seeking out specific genes that influence behavior

-No single “obesity” gene

-Location of multiple genes that “trigger” certain behaviors

-Prenatal DNA scans in China

II. Evolutionary Psychology: Understanding Human Nature

-Evolutionary Psych

-What makes us so alike as humans

-Darwin

-Competition for survival

-Biological and behavioral

A. Natural Selection and Adaptation

-Domestication of animals (the fox)

-More than 30 generations of mating the top 5% tamest

B. Evolutionary Success Helps Explain Similarities

     -95% of genetic variation exists within populations

i. Outdated Tendencies

-The need for sweets and fats…

-Hard to come by in ancient times, not so hard now

-Biological tendencies from the past are harming us today

ii. Evolutionary Psychology Today

-Infants and fear of strangers at walking age

-Biological fathers less likely to harm their children

-Phobias about guns and electricity?

-Universal thought?  Collective unconsciousness

C. An Evolutionary Explanation of Human Sexuality

-Men and women are very similar!

-Adaptation was different

i. Gender Differences in Sexuality

-Men have a stronger sex drive

-Misattribution of friendliness as sexual interest

ii. Natural Selection and Mating Preferences

-Survival of the “fittest”

-What is considered “attractive”

-Science shows that both men and women have specific desires

D. Critiquing the Evolutionary Perspective

-Backwards reasoning is dangerous