Recent findings reported by NewScientist.com point to a link between a specific gene in men and their propensity for monogamy.
Curiously, the speculation regarding genes and monogamy unflatteringly arose from the study of voles, otherwise known as meadow mice. These voracious little mammals spend most of their time in burrows. Thanks to generations of Marlin Perkins types, zoologist have documented that prairie voles are strictly monogamous but meadow voles are promiscuous. In search of a biological reason for this behavior, scientists discovered that variations in receptors for the hormone vasopressin are a contributor. In the name of science (and the future of love everywhere), the next step was to see if some physical similarity existed in humans.
Hasse Walum and colleagues at the Karolinska Institute in Stockholm, Sweden looked at the various forms of the gene coding for a vasopressin receptor in 552 Swedish people. (Vasopressin is a hormone related to the "cuddle chemical" oxytocin.) All study subjects were in long-term (five years +) heterosexual partnerships. Researchers from the land of Abba found that variation within a section of the gene called RS3 334 was linked to how men bond with their partners.
Technically speaking, men can have none, one or two copies of the RS3 334 section. The higher the number of copies, the worse men scored on the study's measure of pair bonding. Supporting these observations, men with two copies of RS3 334 were more likely to be unmarried than men with one or none, and if they were married, they were twice as likely to have a marital crisis.
Biology Determines Commitment?
Walum and his team weren't able to interview the test subjects about the quality of their relationships, so the study offers no insights on whether the participants were truly faithful. Additionally, the study was not clear on exactly how multiple copies of RS3 334 affect expression of the vasopressin receptor. In other words, scientist think they're on to something, but have no idea how it plays out in our most intimate relationships.
If you're feeling like you need a cheek swab from your partner about now, know that the science of love is far from perfected. Certainly, it cannot account for non-biological factors such as character and choice. these are the things that contribute most to commitment and monogamy, at least in humans. The voles aren't talking.