Genetic Influences on Behavior Chapter 3 Genetic Influences on Behavior

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

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

Genes: Their Location and Composition Nucleus Chromosome Gene Cell DNA

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

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

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

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

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

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

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