Chapter 3

1. Chapter 3 • The Nature and Nurture of Behaviour

2. Genes: Our Biological Blueprint • Chromosomes • threadlike structures made of DNA that contain the genes • DNA (deoxyribonucleic acid) • complex molecule containing the genetic information that makes up the chromosomes • has two strands-forming a “double helix”- held together by bonds between pairs of nucleotides

3. Genes: Our Biological Blueprint • Genes • biochemical units of heredity that make up the chromosomes • a segment of DNA capable of synthesizing a protein • The paradox 30,000 genes for 300,000 proteins • Genome • the complete instructions for making an organism • consisting of all the genetic material in its chromosomes

4. Evolutionary Psychology • Natural Selection • the principle that, among the range of inherited trait variations, those contributing to survival will most likely be passed on to succeeding generations • Mutations • random errors in gene replication that lead to a change in the sequence of nucleotides • the source of all genetic diversity

5. Evolutionary Psychology • Evolutionary Psychology • the study of the evolution of behavior using the principles of natural selection • Behaviour expressed prior age of mating can possibly be selected for by natural selection • Gender • in psychology, the characteristics, where biologically or socially influenced, by which people define male and female

6. Evolutionary Psychology • Men everywhere preferred attractive physical features suggesting youth and health

7. Behavior Genetics • Behavior Genetics • study of the power and limits of genetic and environmental influences on behavior • Environment • every nongenetic influence, from prenatal nutrition to the people and things around us

8. Romanian Orphanages • Elinore Ames (1997) study • Early deprivation and malnutrition • When adopted before 4 months there seem to be no long term consequences • When adopted after 8 months or more they were developmentally delayed (could not walk or talk at 2.5 years) • Parents adopting more than one orphan had much more difficulty and stress in parenting

9. Identical twins Fraternal twins Same sex only Same or opposite sex Behavior Genetics • Identical Twins • develop from a single zygote (fertilized egg) that splits in two, creating two genetic replicas • Fraternal Twins • develop from separate zygotes • genetically no closer than brothers and sisters, but they share the fetal environment

10. Behavior Genetics • Temperament • a person’s characteristic emotional reactivity and intensity • Heritability • the proportion of variation among individuals that we can attribute to genes • may vary, depending on the range of populations and environments studied

11. Behavior Genetics • Interaction • the effect of one factor (such as environment) depends on another factor (such as heredity) • Molecular Genetics • the subfield of biology that studies the molecular structure and function of genes

12. Early Environmental Influence • Two placental arrangements in identical twins

13. Twins (Video Clip)

14. Rat brain cell Impoverished environment Rat brain cell Enriched environment Environmental Influence • Experience affects brain development

15. Normal Brain Growth

16. Environmental Influence • A trained brain

17. Environmental Influence • Culture • the enduring behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next • Norm • an understood rule for accepted and expected behavior

18. Environmental Influence • Personal Space • the buffer zone we like to maintain around our bodies • Memes • self-replicating ideas, fashions, and innovation passed from person to person

19. The Nature and Nurture of Gender • X Chromosome • the sex chromosome found in both men and women • females have two; males have one • an X chromosome from each parent produces a female • Y Chromosome • the sex chromosome found only in men • when paired with an X chromosome from the mother, it produces a male child

20. The Nature and Nurture of Gender • Testosterone • the most important of the male sex hormones • both males and females have it • additional testosterone in males stimulates • growth of male sex organs in the fetus • development of male sex characteristics during puberty

21. Testosterone effects: • Dr. Daryl O'Connor (2000), a co-author of the study, said: "Previous research has shown that men outperform women on spatial ability, such as map reading, and women outperform men on verbal ability. It is a well-known gender difference. • The fact that higher levels of testosterone improved men's verbal fluency was unexpected and these findings give us a preliminary insight into the non-sexual benefits of the hormone." The World Health Organization study was presented at the British Psychological Society's annual conference in Winchester.

22. Role • a set of expectations (norms) about a social position • defining how those in the position ought to behave

23. The Nature and Nurture of Gender • Gender Role • a set of expected behaviors for males and females • Gender Identity • one’s sense of being male or female • Gender-typing • the acquisition of a traditional masculine or feminine role

24. Same Gender relationships • Deborah Tannen • He says She says (Video Clip) • Sexism

25. The Nature and Nurture of Gender • Social Learning Theory • theory that we learn social behavior by observing and imitating and by being rewarded or punished • Gender Schema Theory • theory that children learn from their cultures a concept of what it means to be male and female and that they adjust their behavior accordingly

26. Gender Typing

27. Families with both parents

28. Harris (1998) – peer influence • Don’t Blame Your Parents: The Nurture Assumption on Trial (talk at APA) • Parents influence on their children is context dependent - specific to home. • “The idea that children need constant attention and affection until the day they leave for college is a product of our culture.” – an unfounded assumption • Theory of group socialization is that the people who had formative influence are not parents by the peer group as a whole.

29. Addendum: Natural and not-so-natural Selection • Basic idea of natural selection is that only some survive to mate and carry forward their genetic code • So selection into the gene pool is from the offspring that have offspring • The simple notion of mating competition has been used as a major explanatory approach by evolutionary psychologists • However there are other situations that limit the gene pool

30. Other Natural Selection mechanisms include • Miscarriages and spontaneous abortions • Death during pregnancy of mother or child • Death in childbirth of mother or child • (size of head and size of pelvis) • Fatal childhood diseases • Accidental death of children (childhood mortality rates)

31. Not-so-Natural Selection include • Genocide (as in Ruanda) • Child and adolescent suicide • Child Mortality related to child labour • Child armies (function of lighter guns) • Selective small family size (Canada and income) • (China - one child social policy and preference for males) • Selective Abortions (in India 97% of abortions are female) • Adoption Services

32. Selective Application of Medicine • Fertility clinics for the advantaged • Genetic Screening - Downs Syndrome • Genetic Screening - aborting females • Intensive Care for premature babies ($100-200k per case) • Genetic therapies

33. Selective applications of Science • Selective Cloning of the Very Wealthy? • Patenting of mutant genetic code • Targeted Biological Weapons (selective flu) • Enhanced training in how to kill via videogames for children • Controlled famines with gene pool consequences • Implanted identification devices (Digital Angel)