Summary
Principles of Genetics
- Behavior geneticists study the genetic basis of behavior and
personality differences among people.
- The more closely people are biologically related, the more genes they
share.
- Traits can be monogenic (determined by one gene) or polygenic (determined by several genes).
- Researchers use heritability to determine how much of a
trait’s variation within a population is due to genes.
Types of Genetic Studies
- Psychologists use family studies, twin studies,
and adoption studies to see whether, and to what extent,
characteristics are genetic.
- Heredity interacts with environment to influence psychological
traits.
Evolution and Natural Selection
- Evolution is the change in the frequency of genes in a
population.
- Charles Darwin proposed the theory of natural
selection, which states that inherited characteristics that give an
organism a survival or reproductive advantage are passed on more
often to future generations than other inherited characteristics.
- An adaptation is an inherited characteristic that increases
in a population because it provides a survival or reproductive advantage.
- Inclusive fitness is the reproductive fitness of an
individual organism plus any effect that the organism has on increasing
reproductive fitness in related organisms.
- Evolution relies on mutations, or small changes
in genes.
Evolutionary Psychology
- Evolutionary psychologists use evolutionary theory to explain
patterns in psychological characteristics.
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Researchers study mating behavior to investigate aspects
of evolutionary psychology.
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Parental investment refers to all the resources spent
to produce and raise offspring.
- Sexual selection refers to the tendency of females to choose
mates based on certain characteristics, which are then passed on to their male
offspring.
