Subjective well-being. Sex-specific effects of genetic and environmental factors

Genetic and environmental factors in subjective well-being were investigated. Special attention was paid to sex-specific effects. A classical twin design was applied, based upon data from 5140 young adult twins (same and opposite-sex). Structural equation modelling was used to estimate effects from additive genes, genetic interaction, common environment and non-shared environment. The best fitting model involved an additive genetic factor and non-shared environment. There were only marginal sex differences in mean levels of subjective well-being, and no differences in variance. Yet, there were sex differences in the degree of heritability (0.54 for women and 0.46 for men). Additionally, the correlation between the male and female genetic factors was 0.64, suggesting that, in part, different sets of genes may influence variation in subjective well-being for men and women. A dual mechanism process of genetic influence upon well-being is proposed, comprising the notion of interaction between genotypes and cultural value systems.