1. Chapter 4 Nature/Nurture Evolution Behavior-Genetics

2. The Nature of Behavior and Mental Processes Chromosomes Hormones Brain Structures/Chemicals

3. Genes: Our Biological Blueprint  Chromosomes  23 Pair  Contain genetic material  DNA (deoxyribonucleic acid)  Building blocks of the chromosomes  has two strands-forming a “double helix”  Genes  segment of DNA capable of synthesizing a protein

4. Gender and Nature 23 rd Chromosome = Sex  X from egg  X or Y from sperm  XX = Female  XY = Male Testosterone (androgen) Levels/Testes Estrogen Levels/Ovaries Brain Development Identity

5. Cognitive Differences No differences for most cognitive abilities Verbal, reading, and writing— females consistently score higher Spatial skills —males outscore females on mentally rotating objects, females score better on remembering locations of objects Math Skills— males score slightly better than females

6. The Role of Hormones Hormones are chemicals that control bodily responses such as emotions, growth, and sexuality.  Males have more androgen.  Females have more estrogen.  Hormones play a lesser role in human development and behavior than they do in animals. The sex hormones are estrogen and androgen.

7. The Nurture of Behavior and Mental Processes Social Learning Theory Parenting Peers Culture Norms

8. The 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

9. Gender Role Stereotypes The beliefs and expectations people hold about the typical characteristics, preferences, and behaviors of men and women “I’m Glad I’m a Boy, I’m Glad I’m a Girl”

10. Gender Role Development Between ages 2-3 years, children can identify themselves and other children as boys or girls. The concept of gender or sex, however is based more on outward characteristics such as clothing. Toddler girls tend to play more with dolls and ask for help more than boys Toddler boys tend to play more with trucks and wagons, and tend to play more actively After age 3 years we see consistent gender differences in preferred toys and activities

11. The 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

12. The Nurture of Gender  Two theories of gender typing

13. David(Brenda) Reimer What, if any, aspects of David’s development support the nature theory of gender? What aspects support the nurture theory?

14. Personality Differences No significant differences between men and women on most characteristics Women tend to be more nurturant than men (very broad) Men tend to be more assertive than women (very broad)

15. Male/Female Differences The only activity that is clearly defined along gender lines is reproduction. All other activities are shared by both sexes to different degrees. Nurturance: Women generally show more empathy, but males can also be nurturing. No one has proven the existence of strong maternal instinct in humans.

16. Physical activity: Boys start out more physically active. By adulthood, differences in activity levels between genders have disappeared. Aggression: Males are aggressive in more situations than females. Females do show aggression in some situations, however.

17. Mathematical Ability Studies are not clear and have not as yet conclusively shown that males are innately better at math.  Males do better than females on the SAT math section, but study findings have not been consistent.  Teachers and parents have higher expectations for males.  Females may avoid difficult areas such as math.

18. Verbal Ability Includes not just speaking but also word problems, reading and writing. Generally, girls do better than males until early adolescence.

19. Evolutionary Psychology  Evolutionary Psychology  the study of the evolution of behavior and the mind, using the principles of natural selection  Gender  in psychology, the characteristics, whether biologically or socially influenced, by which people define male and female

20. Evolutionary Psychology  Natural Selection  Mutations  random errors in gene replication that lead to a change in the sequence of nucleotides  the source of all genetic diversity  Maximizing Fitness  Maximizing the fitness of your gene pool by selecting a mate with healthy genes and thus increasing your chances of producing healthy offspring.

22. Evolutionary Psychology Critiquing the Evolutionary Explanation  Evolutionary psychologists make too many hindsight explanations.

23. Behavior Genetics BBehavior Genetics sstudy of the relative power and limits of genetic and environmental influences on behavior EEnvironment eevery nongenetic influence, from prenatal nutrition to the people and things around us

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

25. 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

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

27. Environmental Influence  Experience affects brain development Impoverished environment Rat brain cell Rat brain cell Enriched environment