1. Myers’ PSYCHOLOGY (6th Ed)
Chapter 3
The Nature and Nurture
Of Behavior
James A. McCubbin, PhD
Clemson University
Worth Publishers

2. 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

3. 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

4. Genetics and Behavior
Nucleus
Chromosome
Gene
Cell
DNA

5. Evolutionary Psychology
Natural Selection
the principle that, among the range of inherited trait variations, those contributing to 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

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

7. Evolutionary Psychology
Men everywhere preferred attractive physical features suggesting youth and health

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

9. Behavior Genetics Identical Twins Fraternal Twins
Same
sex only
Same or
opposite sex
Identical Twins
develop from a single zygote (fertilized egg) that splits in two, creating two genetic replicas
Fraternal Twins
develop from separate zygotes
genetically no closer than brothers and sisters, but they share the fetal environment

10. 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

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

12. Environmental Influence
Two placental arrangements in identical twins

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

14. Environmental Influence
A trained brain

15. 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
Norm
an understood rule for accepted and expected behavior

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

17. 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
Y Chromosome
the sex chromosome found only in men
when paired with an X chromosome from the mother, it produces a male child

18. 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

19. 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

20. 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

21. The Nature and Nurture of Gender
Percentage agreeing “The activities of married women are best confined to home and family”
Men
Women
1967 ‘71 ‘75 ‘79 ‘83 ‘87 ‘91 ‘95
Year 70 60 50 40 30 20 10
Percentage