Happiness and success: genes, families, and the psychological effects of socioeconomic position and social support.

Although there is considerable evidence linking success -- including wealth, marriage, and friendships -- to happiness, this relationship might not reflect, as is often assumed, the effects of the proximate environment on well-being. Such an interpretation is contravened by evidence that both happiness and the environment are influenced by genetic factors and family upbringing. Using the National Survey of Midlife Development in the United States, which includes a subsample of twins, this study evaluates the relationship between happiness and various features of success before and after eliminating the influence of endowments. The results suggest that many putative indicators of the environment are highly heritable and, indeed, that the same genes that affect the environment may affect happiness as well. Yet the results also suggest that the role of genetic endowments varies considerably across different features of success, suggesting complex patterns of selection, reinforcement, and causation among genes and the environment.