Scientists Discover the Monogamy Gene

Each cell in the human body contains about 25,000 to 35,000 genes, which carry information that determines our traits; straight or curly hair, short or long legs, and even how we smile or laugh. Each gene has a special job to do, but what happens when genes don’t work right or have changed in some way? Researchers think that altered or mutated genes may be partly to blame for lung problems, cancer and many other illnesses. And now, scientists believe a certain gene variant may be linked to marital monogamy.

Researchers at the Karolinska Institute in Stockholm, Sweden, led by behavioral geneticist Hasse Walum, began their research after being intrigued by a study showing that one genetic variation in male voles, which are mouse-like rodents that have darker coats and fatter tails, caused them to form life long bonds with their mates, while others mated promiscuously. “Maybe this same gene will affect humans,” Walum said.

For their study, the team looked at 552 Swedish twins and their partners of at least five years. Most (82 percent) were married, and 18 percent were living together but not married. They had DNA tests, were given a questionnaire, and were visited at home by the researchers. They were also given a test that estimates how bonded one is to one’s mate. The men who had the gene variation, called 334 allele, scored lower on the bonding test and were not as likely to be married as men without the gene variation. And men carrying two copies of the allele were twice as likely to have a dysfunctional marriage, including a threat of divorce. “Fifteen percent of the men carrying no 334 allele reported marital crisis, whereas 34 percent of the men carrying two copies of this allele reported marital crisis,” the researchers reported. Partners of the men without the gene variation reported that they were the most satisfied with their relationship.

The study suggests that two of every five men have this gene variation. The team isn’t sure what the variation does to a man’s behavior, but believes it has to do with their ability to communicate and show compassion. However, Walum stressed that larger studies need to be done to test how the variant affects a human being’s behavior and says other factors such as culture, religion, and family background also shape a man’s marital behavior.

So, does having allele provide a rationale for cheating? Experts say “NOT AT ALL.” However, being aware that you have the genetic variation can provide the opportunity to treat it, much the same as providing skills to someone who is having social difficulty. And just as an alcoholic avoid bars and liquor stores, people who feel they are at risk of cheating should avoid situations that may lead them to temptation, such as regularly carpooling with a coworker of the opposite sex or going out to clubs or bars at night without your spouse.

There are things we do because we know we should, and most of them are not the easiest choices. Everyone is capable of deciding to be faithful to their significant other, regardless of their genetic make-up.

The study results are published in the September 2 edition of Proceedings of the National Academy of Sciences.