'Bonding Gene' Could Help Men Stay Married

But the vasopressin 1a gene is likely not the only factor influencing a man's ability to form true and lasting bonds, he added.

"It's unlikely to be a single gene [at work] -- it's likely to be multiple genes that are expressed incompletely and interact with the environment," said Lucas, who is also a psychiatrist at New York Presbyterian Hospital/Weill Cornell Medical Center. He pointed out that what psychologists call "temperament" -- the individual palette of emotions and behaviors that even babies display -- is probably "hard-wired" by our genetics. "But temperament, through training and experience, becomes personality," Lucas said. "And personality is a complicated situation, of course, and it involves the ability to commit."

So, it's too early for men to blame their inability to commit on a single gene, although Lucas guesses it's an excuse that's "certainly going to be used."

For his part, Walum agreed that men and their spouses shouldn't read too much into the finding.

"Taken together, the effect of the gene variant that we have studied on human pair-bonding behavior is rather small, and it can not, with any real accuracy, be used to predict how someone will behave in a future relationship," he said.

Walum also noted that the finding would probably not be applicable to women, since vasopressin appears to be tied to social bonding in males, but not females.

In a related study, also in the same issue of the journal, researchers at the Pacific Health Research Institute in Honolulu said they've identified a gene strongly linked to extended health and life span in humans. The FOXO3A gene, involved in insulin signaling, is just the second gene ever found that is closely tied to longevity, the researchers said. In their study of Japanese-American men, those who lived to an average age of 98 had a specific variant of FOXO3A compared to men who died at younger ages, the team said.

More information

There's more on genes and behavior at Stanford University.

SOURCES: Hasse Walum, department of medical epidemiology and biostatistics, Karolinska Institute, Stockholm, Sweden; John Lucas, M.D., clinical assistant professor, psychiatry, Weill Cornell Medical College, and psychiatrist, New York Presbyterian Hospital/Weill Cornell Medical Center, New York City; Sept.1-5, 2008,Proceedings of the National Academy of Sciences