Genes and Behavior

Behavioral genetics studies the extent to which behaviors run in families. They also study segments of DNA associated with particular behaviors as well as common behaviors shared by identical twins. Characteristics such as skin color, risk taking, and metabolism are said to be caused by the interaction of genes and are the product of polygenic transmission. Traits determined by a single gene are passed on by monogenic transmission. The extent to which observed differences in a trait are due to underlying genetic differences is known as heritability. Heritability refers to actual measurements drawn from actual samples. Twin studies, adoption studies, and twin-adoption studies are examples of research into heritability. The question is not whether a trait is caused by genetics but the manner in which genetic factors and environment work together. Thus, heritability is a measure of the degree of variance attributable to genetic makeup. Genetic psychology seeks to understand the relationship between genetics and behavior.

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