Did you know male pair-bonding is influenced by genetic variation?
Genetic changes in the vasopressin receptor gene influence pair-bonding in men
It is said that swans mate for life. Can the same be said for humans? Modern genetic tests tell us that this is more of a myth than the truth. When biologists talk about monogamy, they really mean genetic or sexual monogamy. However, according to recent studies, “social monogamy” is on the rise. This term refers to a couple having shared living arrangements and cooperating in a family structure, but not remaining sexually exclusive. Biologists struggle with the question of whether this is a new social norm, or whether it actually reflects certain aspects of human nature.
Scientifically, monogamy is less advantageous to a man than it is for a woman. A man who mates with multiple women will have more children, and therefore spread his genetic material more widely. Yet, this benefit is balanced against the evolutionary advantage gained from the human family structure. Could the AVPR1A gene decide the fate of a family?
Vasopressin and the vasopressin receptor (encoded by AVPR1A) are best known to control water retention and blood pressure. Aside from this, specific changes in the AVPR1A gene can also influence social behaviour. For example, such changes are seen in dancers and are important for developing social interactions on the dance floor. Other changes are associated with musical ability, as it appears that pathways in the brain that we use to perceive music are the same ones we use when we connect with other people. However, one particular genetic change is responsible for turning AVPR1A into the ‘pair-bonding’ gene.
The specific variant of the AVPR1A gene that is linked to decreased pair-bonding in men is known as the RS3 334 allele. Men with the RS3 334 allele are less likely to form strong bonds with their partners. In one study, 34% of men with this genetic variation experienced marital crisis or the threat of divorce, compared to 15% of men who do not have the RS3 334 allele. Men with the RS3 334 allele were also more likely to chose cohabitation over marriage, and tend to be less affectionate towards their partner.
So, if some men are genetically pre-programmed to have decreased pair-bonding, can their behaviour really be described as a “fear of commitment”? This actually is a small part of a much larger question, just how much are we defined by our genes? We will soon be entering a future where our genetic makeup will be readily available. Whether we use this knowledge to excuse our bad behaviours, or whether we choose to seek education and counselling, or just make a personal commitment to overcome our limitations, will ultimately determine how this genomic revolution will impact our society.