Well-being and ill-being: shared environments, shared genes?

Abstract

The nature of the associations between life satisfaction, anxiety, and depression remains elusive. Using questionnaire data from a large population-based sample (N = 6326) of young adult Norwegian twins (aged 18–31 years) we explored the extent to which latent genetic and environmental factors are (1) common or distinct, and (2) sex-specific. Phenotypic correlations ranged between 0.44 and 0.70 in females, and between 0.41 and 0.69 in males. Environmental influences accounted for 75% of these correlations in females, and less than 50% in males. Genetic and environmental sources of life satisfaction, symptoms of anxiety, and symptoms of depression were shared mostly, but the magnitude of the effects was different in males and females. In both sexes, however, aetiological factors enhancing life satisfaction were simultaneously protecting against feelings of sadness and displeasure, but contributed less to countervailing anxiety and tension.