Sociability and positive emotionality: genetic and environmental contributions to the covariation between different facets of extraversion.

The relation between sociability and positive affect is one of the most often replicated results of research on personality and subjective well-being. It is shown how behavior genetics can contribute to our understanding of the covariance between sociability and positive emotionality. The results of a multimethod behavior-genetic study with 158 monozygotic and 120 dizygotic twins are reported. In this study, sociability and two components of positive emotionality (positive affect, energy) were assessed by self-report and other report. Additionally, positive state affect was assessed in five situations and aggregated across situations. The results showed that there are strong genetic correlations between all variables. Furthermore, there are substantive correlations between the nonshared environmental components of the different variables. Shared environmental influences, however, seemed to be unimportant for explaining the correlations between sociability and the different components of positive emotionality. The results are discussed with respect to their implications for future research on sociability and positive emotionality.