The science of infidelity is still in its infancy, but recent studies have suggested that genetic factors may partly explain why some people are more likely than others to cheat on their romantic partners. However, genetic factors are never the only factors when it comes to human behavior, and these recent research results by no means suggest that cheaters now have a free pass. The largest and most prominent study on the genetics of infidelity came out of the University of Queensland and was published in 2014 in the journal Evolution and Human Behavior. This study suggested that variations in vasopressin receptor genes correlated with higher instances of infidelity among women, and other studies have linked both vasopressin and oxytocin receptor genes to partner bonding and varying levels of marital quality for both women and men. Some people felt that the results of this research essentially excused their own past instances of cheating. They weren’t alone—some people who had been cheated on in the past believed that these results justified their former partners’ behaviors. But the reality is that while genetics may help provide an explanation for why certain people are serial cheaters, it does not excuse that behavior.
Both Genes, Environment Influence Behavior
The longstanding psychological debate referred to as “nature vs. nurture” is all about genes vs. environment and which has more influence on behavior. There are many people who strongly believe that our genes largely dictate who we become, and there are others who believe that people are products of their environment and experiences. But there is overwhelming evidence that both are crucially important, and those on both sides of the debate largely acknowledge this fact, even if they cannot agree on which element is the most influential. Furthermore, we now understand that our genomes are not entirely static. External factors such as environment can influence genetic expression, turning genes on and off and affecting how cells read genes. The study of this process is known as epigenetics. As a result of variations in gene expression, not even identical twins who are born with identical DNA will necessarily have the same cellular and physiological traits.
Genes Don’t Guarantee Cheating
So while genetics can influence behavior, and may even influence the decision to cheat on a romantic partner, that is a far cry from saying that genetics make infidelity inevitable. In fact, the Queensland study makes that clear: if the genetic variations associated with infidelity guaranteed infidelity, the researchers would have seen a 100 percent correlation between those who had certain variants and those with a history of cheating. In reality, the correlation, though notably higher than what was found in those without the gene variants, was far from 100 percent. Nor is it plausible that a small handful of genetic variations (among the approximately 24,000 genes that human beings have) could be responsible for something as complex as infidelity. But even if scientists are able to identify many more genes that are associated with cheating, it’s still not going to guarantee that certain people are destined to step out on their partners. In the moment, when a variety of factors, genetics included, have helped to create the opportunity to cheat on your partner, you still have the choice to go through with it or to remain faithful.