Heritability of the Big Five Personality Dimensions and Their Facets: A Twin Study


  • This research was partially supported by a fellowship from the Canadian Psychiatric Research Foundation to K. L. Jang, and by Grant MA9424 from the Medical Research Council of Canada and Grant 181(91-2) from the British Columbia Health Care Research Foundation to W. J. Livesley.

Address correspondence to Kerry L. Jang, Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, Canada V6T-2A1.


ABSTRACT The genetic and environmental etiology of the five-factor model of personality as measured by the revised NEO Personality Inventory (NEO-PI-R) was assessed using 123 pairs of identical twins and 127 pairs of fraternal twins. Broad genetic influence on the five dimensions of Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness was estimated at 41%, 53%, 61%, 41%, and 44%, respectively. The facet scales also showed substantial heritability, although for several facets the genetic influence was largely nonadditive. The influence of the environment was consistent across all dimensions and facets. Shared environmental influences accounted for a negligible proportion of the variance in most scales, whereas nonshared environmental influences accounted for the majority of the environmental variance in all scales.