Three methods used to establish geneticbehavior relationships are selective breeding, twin studies, and adoption studies

Three methods used to establish geneticbehavior relationships are selective breeding, twin studies, and adoption studies. Twin and adoption studies lead to signifi cant heritability estimates for intelligence and most personality characteristics. The overall heritability for personality has been estimated to be .4 to .5; that is, 40 to 50% of the variance in personality characteristics is due to genetic factors. However, there is evidence that heritability estimates are infl uenced by the population studied, personality characteristics studied, and measures used.