1 1 Nature, Nurture, and Human Diversity Chapter 3 Psy12000 What Makes You You? • Each of us is unique. – We look different, we have varying personalities, interests, and cultural and family backgrounds 2 What Makes You You? • We also share a lot in common. – We share a biological heritage, cut us, we bleed. – Shared brain architecture predisposes us to sense the world, develop language, and feel hunger through identical mechanisms. – We prefer sweet tastes to sour; we divide color spectrum into similar colors, we feel drawn to behaviors that produce and protect offspring. 3 What Makes You You? – We fear strangers at 8 months. – We prefer company of those with similar attitudes and attributes. – We know how to read on another’s smiles and frowns. – We affiliate, conform, return favors, punish offenses, organize hierarchies of status, and grieve a child’s death. • This is Human Nature. 4 What Makes You You? • What causes our diversity, and our shared human nature? • How much are human differences shaped by our differing genes? • How much by our environment? – From nutrition within the womb to social support while nearing the tomb? – Our upbringing? Our culture? Our current circumstances? 5 6 What is the Nature-Nurture Debate? What accounts for our behavioral proclivities, talents, abilities, personality, pre-dispositions, intelligence, temperament? Are we born with these differences? (Nature) Or, do we acquire these differences from our parents’ influence, societal influence, friends, etc? (Nurture)2 7 Nature Evolutionary Psychology: Understanding Human Nature Natural Selection: Variations (from mutations or new gene combinations) that increase the odds of reproducing and surviving are most likely to be passed on to future generations. An Evolutionary Explanation of Human Sexuality Males: broadcasting; goal is to increase chances of spreading their genes: seek healthy/fertile/nurturing mate(s) Females: narrowcasting; seek mates with resources and potential for long-term investment in their joint offspring: healthy/security/strong mates 8 Nature Evolutionary Psychology: Understanding Human Nature Critiquing the Evolutionary Perspective Post-hoc? Starts from an effect and works backward to an explanation. Gives too little emphasis to social influences. Absolves people from taking responsibility for their sexual behavior Promotes Status Quo 9 Nurture and Human Diversity This perspective emphasizes the influence of parents and peers: Cultural Influences Variations Across Cultures Culture and the Self Collectivistic Individualistic Culture and Child-Rearing Protective Punitive Promote independence 10 Nature, Nurture, and Human Diversity Developmental Similarities Across Groups Gender Development Gender Similarities and Differences 11 Nature vs. Nurture • Genes • For “universals,” looks for similarities across cultures (but can account for differences by sex) • Universals – Aggression? – Altruism? – Nonverbal expressions • Hereditability – IQ – Personality – Temperament • Environment • Looks for differences as a function of culture and immediate environment. • Explains common behaviors in terms of reactions to norms, stereotypes, and expectations. • Includes prenatal environment. 12 Nature, Nurture, and Human Diversity Gender Development The Nature of Gender The Nurture of Gender Reflections on Nature and Nurture3 13 Nature, Nurture, and Human Diversity Similarities Differences Genes: Same set of chromosomes Genes: Genetic anomalies may make us different Biology: Organs and body functions same Biology: May change during development Brain: Same brain architecture Brain: Asymmetry of brain across genders, growth can depend on environment Behaviors: Speak language Behavior: Speak different languages 14 Behavior Genetics: Predicting Individual Differences Behavior Geneticists study our differences and weigh the relative effects of heredity and environment. 15 Genes: Our Codes for Life Chromosomes containing DNA (deoxyribonucleic acid) are situated in the nucleus of a cell. 16 Genes: Our Codes for Life Segments within DNA consist of genes that make proteins to determine our development. 17 Genome Genome is the set of complete instructions for making an organism, containing all the genes in that organism. Thus, the human genome makes us human, and the genome for drosophila makes it a common house fly. 18 How Would You Determine Whether Nature or Nurture Were More Influential? • If you could control your own experiment, what would you do to answer the ultimate questions of nature vs nurture? • Why can’t we do these experiments? • What do we do instead?4 19 Twin Biology Studying the effects of heredity and environment on two sets of twins, identical and fraternal, has come in handy. 20 Twins and Procedures Behavior geneticists study the effects of shared and unique environments on total or partial genetic makeup. 21 Twins Separated at Birth A number of studies compared identical twins raised separately from birth, or close thereafter, and found numerous similarities. Separated Twins Personality, Intelligence Abilities, Attitudes Interests, Fears Brain Waves, Heart Rate 22 Separated Twins Critics of separated twin studies note that such similarities can be found between strangers. Researchers point out that differences between fraternal twins are greater than identical twins. Bob Sacha 23 Adoption Studies Adoption studies, as opposed to twin studies, suggest that adoptees (who may be biologically unrelated) tend to be different from their adoptive parents and siblings. 24 Adoptive Studies Adoptive studies strongly point to the simple fact that biologically related children turn out to be different in a family. So investigators ask: Do siblings have differing environmental experiences? Do siblings, despite sharing half of their genes, have different combinations of the other half of their genes? Ultimate question: Does parenting have an effect?5 25 Parenting Parenting does have an effect on biologically related and unrelated children, but not on everything. Parenting Influences children’s Attitudes, Values Manners, Beliefs Faith,
View Full Document
Unlocking...