Role of genetics in personality traits?

The role of genetics in personality traits is substantial but not exclusive. Research, such as the Minnesota Study of Twins Reared Apart (MISTRA), has found that many personality traits—categorized by the OCEAN acronym (Openness, Conscientiousness, Empathy, Agreeableness, and Neuroticism)—tend to be about 50% heritable. Surprisingly, the family environment contributes very little to these personality traits, with the remaining variance likely due to random factors in the development of the nervous system 1.

Further insights from studies on babies provide evidence that even early reactions to stimuli, like turning towards or away from harsh noises, can predict later traits such as extroversion or introversion, suggesting a genetic underpinning to these behaviors 2.

Overall, understanding that approximately half of the variation in these personality traits arises from genetics and not from family environments can influence how we consider personal behavior and development strategies.