Genetics, Environment, and Personality

Key points

Genetic factors account for much of the variation in personality traits across the lifespan.

Shared upbringing plays a smaller role in adult personality than many clinical models assume.

These findings have important implications for psychotherapy practice.

Most clinicians still underestimate the degree to which genetic factors shape personality traits and personality development. This is not controversial within behavioral genetics , but it remains surprisingly controversial in everyday clinical thinking.

Twin and adoption studies converge on a striking conclusion. Roughly half or more of the variance in most personality traits is attributable to genetic factors (Vukasović & Bratko, 2015). When combined with non-shared environmental influences, that figure exceeds 90