A recent article in the APS Observer, “Genetically Ever After,” reviews the research on genetic influences on marriage, divorce, and marital satisfaction. The litmus test for determining the relative contributions of genetic factors versus environment (‘nature vs. nurture’) is the study of fraternal and identical twins. This research shows that there is a genetic component to marital happiness.
For example, studies of twins in the military showed that the rates of marriage and divorce were more strongly linked in twins than in other siblings. It is important to emphasize, however, that environmental factors also play a part.
What about marital happiness? The results are mixed. There is some evidence suggesting that environmental factors are most important, but one group of researchers identified a specific genetic variant that influences bonding behavior. The research found that men who carried this genetic variant were more likely to have marital difficulties and divorce.