1. Myers’ PSYCHOLOGY For AP
Unit 3C
The Nature and Nurture
Of Behavior

2. 3 BIG Questions
How does genetic inheritance (our nature) and experience (nurture) influence our development?
Continuity versus stages of development?
Stability versus Change…do our personalities change as we age?

3. 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

4. Test Your Knowledge
If chromosomes are books of heredity – the words are _______________ and the letters are ___________________. Sperm is to cell as DNA is to _____________.

5. Genes: Our Biological Blueprint
biochemical units of heredity that make up the chromosomes
a segment of DNA capable of synthesizing a protein
Genome
the complete instructions for making an organism
consisting of all the genetic material in its chromosomes
Molecular geneticists are most interested in studying nucleotide sequences…human genetic diversity consists of differences in our nuclotides.

6. Genes: Their Location and Composition
Nucleus
Chromosome
Gene
Cell
DNA

7. Evolutionary Psychology
Natural Selection
the principle that, among the range of inherited trait variations, those that lead to increased reproduction and 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

8. 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

9. Evolutionary Psychology Con’t
EP is not about how one species evolves into another species over time BUT is about how genetics and environment interact leading to in genetics to fit the environment.
Traits leading to survival are likely to be assed along.
Predisposed to love our children, fear animals, select healthy mates etc.

10. Criticisms of EP Evolution does not imply genetic determinism.
Behavior can be changed.
Does not assume that organisms can compute complex math problems/formulas.
Current adaptive mechanisms in humans are not optimally designed.

11. Evolutionary Psychology
Men preferred attractive physical features suggesting youth and health
Women preferred resources and social status

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

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

14. Twins Fraternal twins are on the rise… Fertility drugs like Clomid
Women are waiting longer to have children
Identical twins share the 100% the same genes but can have different phenotypes…
Phenotype is how a gene expresses itself.
ie…mirror twins – differences in heritability
Personality & Interests.
Sweden has the largest twin registry.

15. Behavior Genetics Temperament Heritability
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

16. Heritability Continued
“Herit” part of inherit – possess something that someone has given to you.
Ability – suffix meaning “capable” – genetically passed on – it is capable of showing up in children of those who possess that quality
ie. parent to child

17. Behavior Genetics Interaction
the dependence of the effect of one factor (such as environment) on another factor (such as heredity)
Example – people who are judged s attractive physically are more likely to get a job or promotion over someone who is less attractive.
Molecular Genetics
the subfield of biology that studies the molecular structure and function of genes

18. Environmental Influence
Two placental arrangements in identical twins

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

20. Environmental Influence
A trained brain

21. 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
Peer influence – slang, food and fashion preferences
Parental influence - are most influential when it comes to values, political beliefs and manners.
Norm
an understood rule for accepted and expected behavior

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

23. 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 child
Y Chromosome
the sex chromosome found only in men
when paired with an X chromosome from the mother, it produces a male child

24. Sex Linked Traits
Sex linked traits are passed to child fro mother through X chromosome.
Usually recessive so when father passes along another X (female), his chromosome dominates the recessive gene.
Most sex linked traits are exhibited in males because there’s only one X
ie. colourblindeness

25. 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
Role
a set of expectations (norms) about a social position
defining how those in the position ought to behave

26. 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

27. The Nature and Nurture of Gender
Gender and Culture

28. The Nature and Nurture of Gender

29. 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

30. The Nature and Nurture of Gender
Two theories of gender typing