Researchers at Binghamton University in New York are reporting in a new study in the journal PlosONE at a version of the DRD4 gene have a greater propensity to engage in promiscuous sexual behavior. As the press release (via ScienceDaily) accompanying the research notes:
The biggest culprit seems to be the dopamine receptor D4 polymorphism, or DRD4 gene. Already linked to sensation-seeking behavior such as alcohol use and gambling, DRD4 is known to influence the brain's chemistry and subsequently, an individual's 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."
Gathering a detailed history of the sexual behavior and intimate relationships of 181 young adults along with samples of their DNA, Garcia and his team of investigators were able to determine that individual differences in sexual behavior could indeed 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," said 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.'
Hmmm. Somehow I doubt that many partners will accept the excuse, "Honey, my DRD4 receptor made me do it."