Without negating the effects of socio-cultural factors on behavior, this is what researchers from Sweden’s Karolinska Institute in Stockholm Department of Medical Epidemiology and Biostatistics suggests in a study first observed in voles (rodents) and later on humans— species sharing the vasopressin gene 1.
Vasopressin known as the antidiuretic hormone (ADH,) a peptide stored in the posterior pituitary gland and released in the blood in a circadian fashion is mainly known to decrease urine formation in the kidneys, causes vasoconstriction which raises blood pressure, and exerts some influence in memory. Also, vasopressin is thought to play a role in social behavior such as male aggression and pair-bonding.
The researchers’ findings suggest, “men with a certain variant, known as an allele, of the vasopressin 1a gene, called 334, tended to score especially low on a standard psychological test called the Partner Bonding Scale. They were also less likely to be married than men carrying another form of the gene. And carrying two copies of the 334 allele doubled the odds that the men had undergone some sort of marital crisis (for example, the threat of divorce) over the past year.” Healthday (09/03/08, Mundell, E.J.)
If true, this gene which controls the production of vasopressin receptors adds up to the body of knowledge that certain genetic factors influence certain behavior with the interaction of other genes. Psychiatrist John Lucas of the New York Presbyterian hospital believes it’s hard to say a single gene controls “marital commitment.” Though the gene may have some effect on mate bonding, it’s unwise to attribute a complex situation such as a rocky marriage to the influence of one gene.