Serial cheaters and randy bachelors often seem deeply unable to stay monogamous; could there be scientific proof to their claims that they “just can’t help it”? According to a new study out from Binghamton University, the propensity for infidelity might possibly be blamed on DNA.
The team of researchers led by Justin Garcia, a SUNY Doctoral Diversity Fellow in the laboratory of evolutionary anthropology and health at Binghamton University, compared choices in sexual behavior with genes. The resulting new theory is that the dopamine receptor D4 polymorphism, or DRD4 gene, may lead to choices about sexual activity. It is the same gene that has been linked to sensation-seeking behavior such as alcohol use and gambling–it is able to influence the brain’s chemistry and thus, behavior.
“We already know that while many people experience sexual activity, the circumstances, meaning and behavior is different for each person,” said Garcia. “Some will experience sex with committed romantic partners, others in uncommitted one-night stands. Many will experience multiple types of sexual relationships, some even occurring at the same time, while others will exchange sex for resources or money. What we didn’t know was how we are motivated to engage in one form and not another, particularly when it comes to promiscuity and infidelity.”
They conducted the study by collecting detailed histories of 181 young adults, and comparing it with samples of their DNA. The team was able to determine that individual differences in sexual behavior seemed to be influenced by individual genetic variation.
“What we found was that individuals with a certain variant of the DRD4 gene were more likely to have a history of uncommitted sex, including one-night stands and acts of infidelity,” noted Garcia. “The motivation seems to stem from a system of pleasure and reward, which is where the release of dopamine comes in. In cases of uncommitted sex, the risks are high, the rewards substantial and the motivation variable – all elements that ensure a dopamine ‘rush.’”
Garcia notes that the study may indicate the first biological evidence that explains how some people may be looking for a serious committed long-term relationship, even if they revel in one-night stands. The results also explain how someone could be very much attached to their partner, commit infidelity, and yet still be madly in love with their partner. It may simply all revolve around a DRD4 variation in these people: distinct differences in the internal quest for a dopamine ‘rush’ can happen separately from the drive for commitment.
“The study doesn’t let transgressors off the hook,” said Garcia. “These relationships are associative, which means that not everyone with this genotype will have one-night stands or commit infidelity. Indeed, many people without this genotype still have one-night stands and commit infidelity. The study merely suggests that a much higher proportion of those with this genetic type are likely to engage in these behaviors.”
“One-night stands can be risky, both physically and psychologically,” concludes Garcia. “And betrayal can be one of the most devastating things to happen to a couple. These genes do not give anyone an excuse, but they do provide a window into how our biology shapes our propensities for a wide variety of behaviors.”
What do you think? Monogamy and infidelity can be very tricky topics. One thing’s for sure, the first person to invent an accurate, over-the-counter DRD4 test kit will never have to work again.