1. Myers PSYCHOLOGY Seventh Edition in Modules
Genetic Influences on Behavior
James A. McCubbin, Ph.D.
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. Genes: Their Location and Composition
Nucleus
Chromosome
Gene
Cell
DNA

5. 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
Mutation
a random error in gene replication that leads to a change in the sequence of nucleotides
the source of all genetic diversity

6. 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

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

8. 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

9. Behavior Genetics Identical Twins Fraternal Twins
Same
sex only
Same or
opposite sex
Identical Twins
develop from a single fertilized egg that splits in two, creating two genetically identical organisms
Fraternal Twins
develop from separate eggs
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 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