Ready to tie the knot after meeting and ‘really getting to know’ Mr. or Mrs. Right? Hold on, because you may want to get your prospective partner genotyped, as sexual monogamy may be an uphill battle for some, simply based on their biology. Recent studies reveal that certain receptor genes may impact your or your partner’s ability to remain faithful, even with the best intentions. Unfortunately, infidelity in marriage often leads to divorce.
Society has historically viewed sexual infidelity as a symptom of an unhappy relationship, immoral or a sign of crumbling social values. However, psychologists have found a link between promiscuity and specific variants of vasopressin and oxytocin receptor genes that may explain why men and women cheat.
Vasopressin is a hormone that has powerful effects on social behaviors like trust, empathy and sexual bonding in humans and other animals. Oxytocin appears to make us more socially trusting, which relates to affection and marital harmony. Mutations in the vasopressin and oxytocin receptor genes – which can alter their functions — could affect human sexual behavior, paving the way for infidelity in some. Experiments point to the amount and way the hormones are processed and the location where they are introduced into to brain by receptor genes as factors in their effect on an individual’s behavior.
In a further twist on the impact of receptor genes on sexual infidelity, is a case of unquenchable thirst caused by a another gene variant. The novelty and thrill-sensation of promiscuity likely triggers the release of dopamine, which conveys a sense of pleasure. A 2010 study found that subjects who carried a variant of one dopamine receptor subtype, the D4 receptor, were 50 percent more likely to report sexual infidelity. This D4 genetic variant reduces binding for dopamine, which implies that these individuals walk around – at baseline – feeling less stimulated and hungrier for novelty than those lacking this genetic variant, making an affair all the more tempting.
So, should these-so called “slaves to biology” get a pass? Not so fast say researchers, correlation is not the same as causation. There are many factors that can contribute to infidelity and a simple genetic variant rarely determines behavior by itself, but if your spouse’s behavior has you scratching your head…just maybe, it’s those cheatin’ genes at work.
Source: New York Times, “Infidelity Lurks in Your Genes”, May 22, 2015