There is No Such Thing as a Divorce Gene.

Let me state this upfront: There is no such thing as a “divorce” gene.

Not that it stopped many media outlets from reporting that such a gene had been discovered a few weeks ago after Hasse Walum, a scientist at the Karolinska Institute in Sweden, and colleagues published a paper in the journal Biological Psychiatry linking a variant of an oxytocin receptorgene, OXTR, to women reporting more unhappiness in their long-term relationships.

Yet many of these news stories and blog posts covering the study suggested that Walum had found “proof” of why some women could not commit, the “cause” of divorce, and that we might have the tools to “predict” which women would be most successful in relationships with just a small blood sample. There are a few problems with all those statements. 1. Genes aren’t deterministic. 2. This was a correlational association study. 3. None of the women who participated were actually divorced.

“It is very interesting, of course, that we found an association between women reporting marital crisis and a gene that we know from prairie vole research that is important to forming a pair-bond,” he told me. “But there are so many environmental factors that are more important if you want to assess the risk of marital crisis or divorce. I was surprised by the ‘divorce’ gene talk, especially since we didn’t collect any real data on divorce—and don’t think it is the correct way to view our study.”

Of course, Walum has been through this kind of exaggerated media circus before. In 2008, he published a paper linking AVPR1A, a vasopressin receptor gene, to men being unhappier in their long-term relationships. Previous work in prairie voles has shown that vasopressin plays an important role in male monogamy and bonding behaviors. The press went wild, calling AVPR1A the “cheating” or the “infidelity” gene. But again, the study was misinterpreted. Walum and his team did not actually ask their human study participants about whether or not they had been unfaithful.

Walum argues that there is a lot of important information that can be gleaned about how and why people fall in love from gene association studies—but these are only first steps in a long journey to understand the neurobiological basis of human relationships. He also cautions that we have to be very careful in how we interpret such studies.

“If you want to explain all the variation in human pair-bonding, you need to look a lot further than just a gene,” Walum says. “I think there is quite a bit of biology involved, but genes can only explain a bit about these behaviors. It is a variety of different factors working together —your genes, your culture, your age, your partner — that creates the true impact. You cannot say that one of these things is more important than another.”

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