Does the Slut Gene Exist?

Img-author-photo---casey-schwartz_182641765133Casey Schwartz in Daily Beast:

Maybe there’s a gene for the belief that genes can explain everything.

If so, I’m missing it.

In the last seven days, we’ve been hearing a lot about the DRD4 gene, dubbed by the media as the “slut gene,” that supposedly explains why certain people are likely to have lots of sex, especially of the adulterous variety.

In a study published last week in the journal PLoS One, a group of researchers, led by Justin Garcia at Binghamton University in New York, took 181 undergraduate-aged subjects, asked them about their sex lives, and ran a DNA test to see which version of the DRD4 gene they had: the 7R+ or the 7R- kind. The DRD4 gene has made headlines before. In fact, it’s a goldmine of scandalous behaviors, linked to everything from alcoholism to impulsive financial decisions. It influences how our brains respond to dopamine, a feel-good neurotransmitter unleashed by new and rewarding experiences. So the Binghamton group had good reason to think that they’d find something if they looked at its role in sexual behavior. And they did find something. But first, here’s what they didn’t find:

They didn’t find that those with one version of the gene had more sex than those with the other. And they didn’t find that the people with the so-called slut gene had more sexual partners, or that they're more likely to cheat.

What they found is that the group who had the 7R+ version was more likely to have had, at one point or another, “a one-night stand,” and that if someone with a 7R+ did cheat in a relationship, they were likely to have done so with more people than their 7R- counterparts.

The study leaves several questions unanswered. Was this 7R+ group really more likely to have had a one-night stand, or just more likely to report it? Did they actually cheat with more partners, or were they simply more willing to reveal the full extent of their adultery? You could just as easily interpret the study’s results this way and declare DRD4 the “candor gene.”

The DRD4 study isn’t an isolated case of shaky genetic science. In fact, it joins a cadre of questionable scientific assertions that link single genes to much broader patterns of behavior.