Marital satisfaction and physical health: evidence for an orchid effect.

Marital distress and conflict are linked to poor physical health. Here, we used behavior genetic modeling to determine the etiology of this association. Biometric moderation models were used to estimate gene-by-environment interaction in the presence of gene-environment correlation between marital satisfaction and self-reported health. Using a sample of 347 married twin pairs from the Midlife in the United States study, we found that genetic influences on the variation in self-reported health were greatest at both high (h (2) = .30) and low (h (2) = .38) levels of marital satisfaction, with the lowest levels of heritability estimated for participants at the average level of marital satisfaction (h (2) = .10). These findings are evidence of the orchid effect: the idea that genetic influences on a phenotype such as physical health are enhanced in nonnormative-both unusually positive and unusually negative-environmental contexts.