Is DNA Really To Blame For Cheating, Promiscuity?

Man and woman undressing

Remember that boyfriend you dumped years ago? The one who couldn't seem to be faithful to you to save his soul? Well, maybe he couldn't help it. Really. A new study out of Binghamton University State University of New York suggests that people who cheat may have a gene variant that's driving them to do so.

All of us carry a gene known as DRD4, but some of us have a variant that leads to risky behavior, including sexual promiscuity. "DRD4 codes for the way dopamine functions in the brain," lead study author Justin Garcia with SUNY's laboratory of evolutionary anthropology and health told AOL Health. "We've done a number of studies on the DRD4 gene, and it's a associated with a lot of thrill seeking behavior. The longer the gene is, the more likely a person is to engage in sensation-seeking activities." The new study is published in the latest edition of PLoS ONE.

After studying 181 young adults and samples of their DNA, Garcia's research team found that variants in the DRD4 gene seemed to influence sexual behavior. Those with the aforementioned gene variant were more likely to engage in sexually promiscuous behavior and to commit infidelity, even when they claimed genuine attachment to a long-term partner.

"Most of our sex happens in relationships," Garcia says, "but we wanted to find out in cases where there is no commitment, what's happening there?" And it's not just about sex. Garcia says that individuals with the DRD4 variant have a greater tendency to participate in all kinds of risky behaviors, including gambling and substance abuse. While he is quick to point out that there is nothing wrong with people who carry the gene variant and plenty of them never engage in sexually promiscuous behavior, he says his research may help explain "how biology really influences how we pick one type of sexual union over another."

What's even more intriguing about research into the DRD4 gene variant, however, is that it could possibly have been a driver in human migration. "DRD4 seems to have developed just as we expanded out of Africa," Garcia points out. He believes it may have had some influence on encouraging the necessary risk-taking to migrate.

"This gene varies in different populations around the globe," he explains. "It looks like populations who have experienced greater migration have a higher proportion of that gene; whereas, people in egalitarian societies have less of it."

None of this means, of course, you should let your cheating spouse off the hook. But it might provide some insight into his or her biological motivations.

Written by Deborah Huso for AOL Health