Myers’ PSYCHOLOGY (7th Ed)

1. Myers’ PSYCHOLOGY (7th Ed) Chapter 3 The Nature (H) & Nurture (E) Of Behavior James A. McCubbin, PhD Clemson University Worth Publishers

2. Ch. 3 The Nature (H) & Nurture (E) Of Behavior Humans’ shared common human behaviors in tropics…or Arctic: EX’s: • Ppl prefer sweet to sour • tend toward off-spring-protecting behav. • best female features show health & youth (reproductive potential) • at about 8 mos., fear strangers • ppl know frowns from smiles from surprise • ppl laugh, cry, worship…etc. In ? of heredity (nat.) vs. environment (nurt.): both very important, but which is which & how to study?

3. Genes: Our Biological Blueprint • Chromosomes: threadlike structures made of DNA…DNA contains the genes -Genes trigger biology…which triggers behav. -46 chromosomesper cell nucleus: 23 from mom, 23 from dad (**Except reprod cells…X + Y) -chrom. made up of DNA(de-oxy-ribo-nucleic acid) -DNA made of genes…traits come from gene complexes (many genes acting together) • 2 strands-forming a “double helix” • Helix held together by bonds between pairs of nucleotides

4. Genes: made of nucleotides Each chrom. has at least 50 mill. ! -4 nucleotide letters: A, T, C, & G • Genome: complete instructions for making an organism consisting of all the genetic material in its chromosomes (Human Genome Project) • All humans have 99.9% of same DNA …(chimps share 95% of human DNA) -but variations at gene sites in DNA give us uniqueness (gene complexes) Evolu. psy. + behavior genetics look at how we are thesame--and different--thru this genetic make-up

5. Nucleus Chromosome Gene Cell DNA Genes: Location & Composition:Cell contains nucleus..contains chromosomes …made of DNA …containing genes (gene complexes) …contain nucleotides (A,C,T,G)…

6. Evol. Psy: the study of the evolution of behavior & the mind, Darwin’s ideas of natural selection EX: see taming the fox (p. 101) thru genetic breeding -selected traits to dominate…dog breeders (& others) do this Natural selection: says there are a certain range of inherited trait variations -those that lead to increased reproduction & survival will most likely be passed on to succeeding generations Antibiotic-resistant bac.: Even bacteria can select the changes that will prevail

7. Natural selection & humans: Come from mutations (random errors in genes): EX: fear of heights & snakes = better ability to survive…& many ppl still fear these -humans very similar, but we notice differences Early on ?'s for ancestors: what to eat, whom or what to trust, whom should I mate? Nat. selection looks at genetic design that solves adaptive problems , leading to survival & spread of these genes

8. Evolutionary theory: only about 35% of Amer. public thinks Darwin's theories are supported by evidence, but "…virtually no contemporary scientist believes he was wrong" Evol. psy. look at many ?'s (see B-p. 103)

9. Sexuality: • Gender: Cross cultural studies:in psychology, the characteristics, whether biologically or socially influenced, by which people define male (M) & female (F)…many cross cultural done to study this… • Men preferred attractive physical features: suggests youth & health • Women preferred resources & social status WHY? 

10. In gender: (p. 103-4) Which gender desires more frequent sex, thinks more about sex…etc.? (duh…) A: men… w/ few exceptions in world -(top 104)….& experiment w/ avg. looking at Florida St. Men: lower threshold for seeing warm response as sexual come-on…”Oh yeah! She wants me!” -can = sex. harassment…or date rape Evol. explanation: Nat. selection = women more relational, men more recreational While 1 woman growing & caring for 1 infant, men still “wide open”

11. What attracts M/W world-wide? (= Crs.–Cul.?) M: woman w/ waist at least 1/3 narrower than hips (= fertility) --tend to be risk-takers in all areas Maybe showing off to attract? (105) {T.Sawyer? } W: look for those bold, dominant, & affluent males …WHY?

12. In singles ads: F offer looks & seek status M offer status & seek looks F also look for potential long-term stability… “dads over cads” …esp. smart F! Why? b/c more likely to send genetic material into future Critiques of the Evolutionary Explanation: Though M’s think about different partners, M & F look for v. similar traits in a permanent mate Bonding to make off-spring better is strong pattern…kids do better w/ 2 good parents.. -Chimps, though, have F that mate w/ many: fool males so they will accept all kids since males more likely to harm & murder other males’ kids? Evolutionary perspective: WHY is it an example of hindsight bias??

13. Behavior Genetics: Study of the relative power & limitsof genetic & environmental influences on behavior • Environment: every non-genetic influence, from prenatal nutrition to the ppl & things around us…our experiences --school, church, society, gov’t., econ., resources, expectations, nutrition (or lack of), culture, world events, etc **Best way to look at the differences betw. heredity vs. environ.: -twin studies(both Fraternal & Identical) -adoption studies

14. RE: M dominant over F: There are exceptions to this…but way more of "the rule" But…changes in society today? Does this mean it has to stay this way?  Humans are NOT locked in to behaviors… Humans have huge ability for & tendency to adapt, so new rules can be established

15. Identical twins Fraternal twins Same sex only Same or opposite sex Behavior Genetics • Identical Twins • single fertilized egg that splits in 2, creating 2 genetically identical organisms -”nature’s closest’ who share DNA, uterus, birth date, & cultural history -monozygotic: 1 egg, 1 sperm • Fraternal Twins • develop from separate eggs • genetically no closer than brothers & sisters, but they did share the fetal environ., cultural history & birth date -Dizygotic: 2 eggs, 2 sperm

16. Inborn traits studies: 24,000 twins show ID twins much more similar than fraternal twins in extraversion (outgoingness) & neuroticism (emotional stability) Strong correlations between fraternal vs. ID twins in divorce (1.6 X vs. 5.5 X more likely if twin divorces) BUT…are ID twins often treated more alike = __?__ variable? However, even if consider this, doesn’t seem to have effect Separated twins studies: EX’s: Read about the “2 Jim’s” (p. 109)!!! 2 twins, 1 Catholic Nazi, 1 Caribbean Jew: but still amazing similarities Researchers have located about 170 separated ID pairs & 200 fraternal pairs Studies show separated ID twins ARE much more similar than separated fraternal twins…….but NOT as similar as ID’s raised together …. So this indicates what?

17. Critics: Twins share womb so this is part of their environment (“birth environment”) Also say ID twins tend to be placed in similar homes -And you can find anecdotal facts that are coincidences for almost anyone (“6 degrees of separation?”) • Adoption studies: another way to look at heredity (nature) vs. environment (nurture) Adoptees personality traits: These are more like biological parents’ traits than adoptive parents’ traits Look at 2 groups of relatives: biological parents/siblings + adoptive parents/sibs *Findings: personality traits & behaviors much more like biological rather than adoptive Behavior genetics FOCUS: Personality traits & DNA

18. So does parenting matter? Not much w/ traits (Traits are mostly innate) But YES w/… -attitudes -manners -values & beliefs -faith -politics Adoptive parents (environment) have influence Parenting DOES matter…& adoptees can do better b/c there is less divorce in adoptive homes (checked for stability in relationships) Temperament:How a person typically responds emotionally How excitable & reactive we are: Easy going? Difficult, tense, fidgety, quiet? (see stats p. 112) Heredity influences temperament… It IS a physiological reaction, involving w/ heart rate, BP, etc. (Which NS?) -Twin studies support this-- ID vs. fraternal

19. Heritability: Proportion ofvariation among individuals attributed to genes; % of variation w/in a population • May vary, depending on the range of populations & environments studied • Extent to which a trait is likely to be inherited… NOTwhat % of your IQ is inherited • Group differences: RE: behavioral traits in differing groups (M/F, different racial groups, economic…): not necessarily explain these EX: Some groups more aggressive? Well…Look at height + weight …ARE highly heritable: But there are recent increases b/c of better nutrition (environ. factor) …& then fast food culture… A new social context can also can cause changes in behaviors (like aggression… mild mannered to aggressive)

20.  Nature enables nurture: How interaction works to shape ppl: We all eat…what we eat depends on cultural interaction Other EX: Wear shoes? = soft feet Always barefoot? = calluses, tough, cracked… • Interaction: dependence of the effect of one factor(like environ.)on another factor(like heredity p. 114:twins: ID + fraternal: Explain these statements: 1. “Children experience us as different parents, depending on their own qualities…” 2. Also as we grow older …..we tend to select environments that fit w/ our natures

21. Molecular Genetics: Subfield of biology that studies the molecular structure & function of genes -tries to ID specific genes influencing behaviors EX: p. 115: Obesity: How would molecular geneticist consider this? (remember to consider interaction!) Those at risk for at least a dozen diseases can now be ID’ed Soon may be able to ID genes for schizophrenia, depression, alcoholism, reading disability, sexual orientation, etc. (THINK: Would you want to know??)

22. Environmental influences: Genetics: responsible for 40-50% of personality traits, so rest is from…? P. 116-7: 30-yr.-old ID twin “neat-freaks” ? Parents: Blame or credit?“Where did we go wrong??” --pushy parents? over-protective? uninvolved? How much help or how much damage? A lot is unknown -more extreme = more effects: really bad or really good…  Resiliency: How kids can survive terrible situations Prenatal /early environment: Womb = 1st environmental influence (see slide 23) Experience & brain development: a) more experiences = more neural connections -another study: brain weight up 7-10 % + # of synapses up 20% …after just 60 days! b) touch & massage: handling, loving on rats--& babies —stimulates weight gain (sign of thriving, growing) & neurological development

23. Rat brain cell Impoverished environment Rat brain cell Enriched Environment: Environmental Influence: Renner & Rosenwieg (& Krech) Study: • Experience affects brain development (NOTE: was replicated twice to be sure!) • Rats w/ the most “toys” were the neural winners… • more experience = more connections

24. Experience & brain development (cont’d.): c) early experiences: some things have “window of opportunity”…if you miss that window closing, then you lose best chance… EX: vision: those w/ early cataracts & later removal… --cells allotted to vision either died out or given over to other functions d) later experiences: “trained” monkeys brains show different activity & connections than untrained (#22) As you learn a skill & work hard on it--music, language skills, athletics, etc.—areas become specialized & more developed to reflect that -so the more we use our brains—surely early, but later also—the more we develop it… use it or lose it!

25. Birth (“early) environment: there are 2 different placental arrangements in ID twins: • 1 set (2/3 of all ID twins) shares placenta (b) • 1 set doesn’t (a) Set w/ shared placenta twins tend to have more similarpersonality than those w/ separate placentas Theories as to why? Food supply? Oxygen? See P. 118

26. Environmental Influence: Wiring up those neurons!! • A trained brain: Learning a task increases connections in an area A: scan b4 learning task B: scan after learning task (a connection is made!)

27. Environmental Influence…con’t. Peer influence: As kids mature, peers (part of environment) gain influence Dr.Judith Harris: Said peers influence more than parents(EX’s p. 120: foods language accents smoking) Note: Many other psychologists disagree w/ this… Parent’s Power: Parents have effect in choosing/influencing peer groups by: schools neighborhoods, etc. AND giving good guidelines in society (religion, values, morals…) Culture:

28. Culture: Enduring behaviors, ideas, attitudes, & traditions shared by a large group of ppl … & transmitted from one generation to the next • In diverse culture, understanding differences is more important— EX: US & Canada Japan: 126 mill. People, 99% Japanese—less diversity

29. Environmental Influence Culture variations: p. 122: Look at EX’s of differences others see in our culture… things we see as “normal” Terms (Cultural influence…cont’d.) • Norms: understood rule for accepted, expected behavior • Personal Space: buffer zone we like to maintain around our bodies (Playing “Space Invader?”) • Memes:self-replicating ideas, fashions, & innovations passed from person to person • Communication: EX: Iraqi misunderstanding US position RE: Kuwait (p. 123) --also see tourist signs  Time variations: past vs. present…20 generations’ difference? Or even 2?? (changes since 1960? + & - )

30. Culture & child-rearing: kids “obey”… or adventurous? -Western cultures let kids “discover” themselves… But used to stress more obedience, respect, manners, etc. Collectivist cultures (grp oriented) vs. individualisticcul. --Asian, African & Lat. Amer.: collectivist…more cooperative, family oriented family 1st, not individual Shame the family = shame on you! “M & D will be disappointed …”: US/Italy=7%; Austral.=14%; Taiwan /Japan=25% Though cultures vary, all tend to have stable kids… Similar devel. across Grps: looking at cross-cultural research gives clues to her. (nat.) vs. envirn. (nurt.) EX: Afr.Amer. men & high BP…Is it a biological “race difference” or……a cultural diet diff.? Disorder differences come from…? IQ differences? Aggression?  All possible Nature/Nurture ?’s for psy research

31. The Nature & Nurture of Gender • X Chromosome: in BOTH M’s & F’s: F have 2 M have 1 -1 from each parent = female child • Y Chromosome: sex chromosome found only in M • X from the mom, Y from dad = M child -7 wks.in utero, biological sex is triggered…again at 4 - 5 mos P. 126-7: Is the behavior of these girls due to prenatal hormones? F embryos (rats, monkeys) injected w/ M hormones show aggressive M behavior… …So early exposure to “wrong” hormones changes behaviors???? At least 1 X chrom. is essential for life.. Though XX = F & XY = M, sometimes these combinations don’t come out right…

32. Abnormal sex chromosome patterns: SCA’s: sex chrom. abnor. -Turner’s syndrome: F w/ only 1 X (XO); ultra feminine…but sterile -Kleinfelter’s syn.: 1-2/1000 M’s have extra X (XXY); tall, hi-voiced, sterile -double Y syn.: 1/1000 M’s = extra Y; XYY; V. tall; low IQ -fragile X syn.: part of X is so thin it seems about to break; most severe retardation levels; it is highly heritable • Testosterone (from M endocr. Sys.…M gonads (testes) • most important of the M sex hormones; in both M & F • additional testosterone in M stimulates growth of M sex organs in the fetus & develop. of M sex characteristics in puberty

33. The Nature & Nurture of Gender Role:set of expectations (norms) about social position, defining how ppl in that position should behave Gender Role: expected M & F behaviors: Who does what in a society? Work? Kids--& sick kids? Laundry? Nomadic vs. agricultural societies: Usually limits F’s power & rights (p. 128) These are changing…especially in MDC’s b/c of needs & demands AND especially among college educ. Populations EX’s of each aspect? -----------------------------------------

34. Gender Identity: our sense of being M or F, based on social categories in a society …what we ARE & it will not change… • Gender-typing: Extent to which we acquire traditional masc. or fem. role EX: M = “man’s man”; macho vs. sissy F = “prissy” ...or tom-boy...butch Know these 2 & differences betwn.: How we “learn” gender:  Gender Schema Theory (we classify): kids learn their cultures ideas about M or F …& adjust behavior accordingly a) cultural learning of gender … which leads to… b) ..gender schema (seeing self & world thru gender lens) …which leads to… c) gender organized thinking + gender-typed behavior  Social Learning Theory: sayswe learn social behavior by observing & imitating …AND by being rewarded or punished for right/wrong behaviors EX’s: “You baked cookies! Good girl!” “Quit being a girlie-boy!” etc.) • rewards + punishments = gender-typed behaviors

35. Two theories of gender typing

36. The Nature and Nurture of Gender • Differences in Gender & Culture: graph: 1994

37. The Nature & Nurture of GenderDifferences over time: graph: 2002

38. Postscript:Reflections on nature & nurture: Genes form us…& it seems true that our genes come from… Variations  natural selection heredity evolution “Genes & experiences: 2 ways of doing the same thing.. …wiring the synapses.”J. Le Doux But not only nature (heredity) forms us, but also the experiences (nurture…envir.) we have… And these come from many things…. not just 1 or 2 things …& not just our parents & peers, but many combinations of things **For those of you who worry about theories of naturalism & evolution taking away from spiritual aspects…be sure to read from bottom of 131 – 132.

39. AP Psy R/W Folders Assignment # : Identifying Genes for Disorders Textbook, p. 115 1) What are some of the risks of selecting for certain traits, genders, etc? 2) a) Would you want to know if you were positive for a gene like depression, bipolar disorder, or schizophrenia? b) Why or why not? 3) a) What is meant by a “designer baby?” b) Why is the idea of a “designer baby” not likely? c) How do you feel about this?