The Nature and Nurture of Behavior CHAPTER 3 p. 110-119 & CHAPTER 11 p. 465-469

1. The Nature and Nurture of BehaviorCHAPTER 3p. 110-119 & CHAPTER 11 p. 465-469

2. WHAT THIS CHAPTER IS! • NATURE • Our biological blueprint • Evolutionary Psychology: • natural selection • Sexuality • Behavior Genetics: is it nature or is it nurture? • Eugenics • Twin studies, adoption studies, temperament, heritability • Gene-environment interaction • The new frontier: molecular genetics

3. NURTURE • Environmental influence • How much credit or blame do your parents deserve? • The prenatal environment • Experience and brain development • Peer influence • Cultural influence

4. Chromosomes • Rod shaped structures found in the center of the nucleus of every cell in the body. • Each sperm and each ovum (egg cell) contains 23 chromosomes. • The chromosomes contain the genes. • The fertilized egg (zygote) and all the body cells that develop from it (except the sperm cells and the ova) contain 46 chromosomes.

5. KaryotypeA photograph of a cell’s chromosomes arranged in pairs according to size http://learn.genetics.utah.edu/content/begin/traits/karyotype/

6. Genes • The basic unit of genetic information • A gene is a segment of DNA capable of synthesizing a specific protein • They determine the nature and the function of the cell. • Made up of nucleotides (A, T, C, & G) • Homozygous- 2 genes in pair are the same • Heterozygous- 2 genes in pair are different • Polygenic –characteristics are influenced by more than one pair of genes • The human genes (about 140,000) are referred to as the human genome. • Agenomeis the full set of genes in each cell of an organism that is made of a sequence of nucleotides organized as coiled chains of DNA

7. Genotype The genetic makeup of a given individual Recessive Gene The gene pair that determines a trait in an individual only if the other member of that pair is also recessive Phenotype The traits that are observably expressed in the individual Dominant Gene One gene of a gene pair that will cause a particular trait to be expressed

9. DNAdeoxyribonucleic acid • The substance that genes are composed of that determines the nature of each cell the body and how it will function. • At each level of the spiral or rungs of the ladder are particular chemical pairs, “double helix.” The arrangement of these pairs along the DNA molecule determines which kind of proteins that will be formed in the cell and determine our physical development.

10. 3.1 billion letters within human DNA

14. Universal Behaviors: Evolutionary Psychology Evolutionary Psychology • The study of the evolution of behavior and the mind using principles of natural selection… adaptive qualities which have helped us survive and spread our genes Fitness • Reproductive success (number of descendents) of an individual organism relative to the average reproductive success in the population Natural Selection • The traits that contribute to reproduction and survival will most likely be passed on to succeeding generations. • Finding one’s ecological niche Adaptation • Inherited characteristic that increased in a population (natural selection) because it helped solves a problem of survival or reproduction during the time it emerged

15. David Bussand the International Team(1994) • 50 scientists studied: 10,047 people in 37 countries in 6 continents • Men preferred women thought to be youthful & healthy • Women preferred men who were mature, dominant, bold, & affluent

16. Evolutionary Psychology:David Buss Research Continued • Men preferred attractive physical features suggesting youth and health • Women preferred resources and social status

17. Males Promiscuous Undiscriminating Competitive and concerned about dominance Prefer beauty and health Like sexual novelty Females Devoted and faithful Cautious Less competitive Prefer resources and social status Like stability and security Human Sex Differences:Universal

18. Innate Human Characteristics • Infant Reflexes • An Attraction to Novelty • A Desire to explore and manipulate objects • An Impulse to be playful and fool around • Basic arithmetic skills

19. Language Acquisition DeviceInnate Mental ModuleNoam Chomsky • Children in different cultures go through similar stages of linguistic development. • Children combine words in ways adults never do. • Adults don’t consistently correct their children’s syntax. • Even children with an Intellectual Deficiency develop language. • Infants can derive simple linguistic rules.

20. “Genes, by themselves, are like seeds dropped onto pavement: powerless to produce anything”

21. Explaining Differences:Behavior Genetics Behavior Genetics • The study of the relative power and limits of genetic and environmental influences on behavior - ex. effect on personality Environment • every nongenetic influence, from prenatal nutrition to the people and things around us

22. Genetic Research • Predicting individual differences • To determine the effects of heredity, behavior geneticists rely on family studies- assess heredity influence of blood relatives on specific traits • Twin studies • Adoption studies Heritability: of any trait, the extent to which variation among individuals can be attributed to their differing genes

23. Identical twins Fraternal twins Same sex only Same or opposite sex Behavior Genetics • Identical Twins (monozygotic) • develop from a single fertilized egg (by 1 sperm) that splits in two, creating two genetically identical organisms • Fraternal Twins (dizygotic) • develop from separate eggs with a separate sperm • genetically no closer than brothers and sisters, but they share the fetal environment

24. Twin Studies 13,000 pairs of Swedish twins, 7000 Finnish twin pairs, 3810 Australian twin pairs Identical twins are more similar than fraternal twins on both extroversion & neuroticism Battery of questionnaires to 850 U.S. twins Identical twins are more similar in abilities, personality traits, & interests. Reported being treated alike Environmental influences on personality traits are most clearly shown by studying identical twins who are raised together and those raised apart

25. The Jim Twins Similar in: brain waves voice intonation interests heart rate personality intelligence Gerald Levey and Mark Newman separated at birth, reunited at age 38 Both volunteer firefighters Separated Twins

26. Adoption Studies • People who grow up together, whether biologically related or not, do not much resemble one another in personality. • Adoptees’ traits bear more similarities to their biological parents than to their care-giving adoptive parents

27. Temperament Studies Temperament: a person’s characteristic emotional reactivity and intensity Traits such as emotional excitability – whether the baby is intense, reactive, fidgety, easy going, or quiet *****tend to remain steady in later years

28. Temperament Studies • Thomas & Chess- longitudinal studies • Easy: 40% • Slow-to-warm-up: 15% • Difficult: 10% • Remaining 35% were a mixture of the 3 Child’s temperament at 3 months was a fair predictor of temperament at 10 years old

29. Temperament Studies • Kagan & Colleagues • Inhibited: 15-20% • Uninhibited: 25-30%

30. Behavior Genetics • Interaction • the dependence of the effect of one factor (such as environment) on another factor (such as heredity) • More like nature via nurture • Epigenetics- heritable changes in gene expression that do not involve modifications to the DNA sequence (based on the environment imposing) • Molecular Genetics • the subfield of biology that studies the molecular structure and function of genes • Genetic mapping

31. Gene-Environment Interaction “Heredity deals the cards; environment plays the hand.” Psychologist Charles L. Brewer (1990)

32. This man celebrated his 113th birthday telling reporters at his home in southern Japan about his joyful life and healthy appetite. Holds the Guinness Book of World Records as the oldest living male. He eats mostly vegetables and believes the key to longevity is not drinking alcohol. He lives with his son, drinks milk every day and has no major illnesses, The Japanese are among the world's longest-lived people, with the number of those aged 100 or older at a record 36,276, shown from a government report ( 2008). Japanese women have topped the world's longevity ranks for 23 years, while men rank third after Iceland and Hong Kong. Genes? You decide!

33. Environmental Influence • Prenatal Environment • Experience and Brain Development • Peer Influence • Culture • Gender

34. Prenatal Care • Diet • The father’s involvement • Age of mother • Illness of mother • Drug use • Alcohol • Teratogens

35. Mutation A random error in gene replication that leads to a change in the sequence of nucleotides; the source of all genetic diversity. • May happen as a result of teratogens, which are substances that can cross the placental barrier and harm an unborn child

36. Experiences and Brain Development • Rosenzweig and Krech’s experiment on rats: • Those living in the enriched environment developed a thicker and heavier brain cortex, and thus more brain cells. • Experience preserves our activated connections

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

38. Environmental Influence • A trained brain

39. Environmental Influences:Parents and Peers are ComplementaryHoward Gardner (1998) “Parents are more important when it comes to education, discipline, responsibility, orderliness. Charitableness, and ways of interacting with authority figures.

40. Environmental Influences: Peers • Peers are more important for learning cooperation, for finding the road to popularity, for inventing styles of interaction among people of the same age. Youngsters may find their peers more interesting, but they will look to their parents when contemplating their own futures.”

41. What Is the Role of Parenting? 1- Do parents really produce future adults with a wounded child within by being irresponsible? 2- Should we blame our parents for our failings? 3- Should we shame the parents of troubled children? 4- Should parents be given less credit for children who turn out great? 5- What is the role of parents?

42. Environmental Influence: Culture • Cultural Universals • Variation Across Cultures • Variation Over Time • Cultural Relativism • Culture and Child Rearing - When to potty train - Walking/talking - Customs regarding family -adolescence

43. Environmental Influence: Culture • 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 • Mores: official rules of behavior sanctioned by law. • Taboos: unthinkable acts

44. VARIATION ACROSS CULTURES • Raising children • Burying the dead • Clothing styles • Use of eating utensils • Personal space

45. CULTURE AND CHILD-REARING • Western cultures: individualism, independence, true to self, marry for love: evidenced by strollers, playpens, car seats, baby sitters • Asian and African cultures: communal, emotional closeness, children don’t have their own bedrooms, not sent to daycare, stronger sense of family self; what shames/honors family brings same to self: spend day with close personal contact; on mother’s back

46. CULTURAL RELATIVISM • In order for behavior to be understood, it must be judged within the context in which it occurs; • Sporting events • Rock concerts • Self-defense • War • Religious practices

47. Environmental Influence • Personal Space • the buffer zone we like to maintain around our bodies; 0-12 inches: personal, 12/18 inches-3ft: social, 3-6 feet: public Memes • self-replicating ideas, fashions, and innovations passed from person to person

48. VARIATION OVER TIME • Since 1960, most western cultures have changed with remarkable speed. Positive changes • The middle class fly on airplanes • Email instead of snail-mail • Air-conditioning for poor and middle class • On-line shopping • Cell phones • Double personal income • Eating out 2.5 more times than your parents did

49. Negative changes since the 60’s • Doubled divorce rate • Teen suicide tripled • Quadrupled juvenile violent crime • Quintupled prison population • Highest depression rate in the world and rising • More hours at work/ less hours at home • Fewer hours sleeping • Less time for friends • Similar cultural changes for Britain, Canada, Australia, New Zealand

50. What causes change over time? • Events can affect fashion short/long skirts • Inventions: microwave ovens • Memes self-replicating ideas, fashions, and innovations passed from person to person • Like genes, memes compete to get copied not into our cells but into our memories Memes can be • True or positive: arithmetic, Bach’s music • Neutral: new pronunciations • False: myths, derogatory phrases