The Genetic Key to a Happy Marriage!

Polygamy - of mice and men, or voles at least - Scientists have shown that a gene variant carried by some men could be the cause of marital dysharmony. The research builds on previous work carried out in rodents showing that prairie voles, which are highly monogamous, carry a different form of a gene called avpr1a compared with their fast and loose cousins the montane or meadow voles, which favour multiple matings. Researchers hadalso shown that adding the gene from the faithful voles to the brains of the polygamous animals could convert them into model monogamous partners.

Meadow Vole © US NPS

Now a similar finding has emerged amongst humans. Paul Lichtenstein and his colleagues at the Karolinska institute in Sweden studied the sequence of the human version of the avpr1a gene region in 552 married or co-habiting couples and compared the sequences with measures of relationship strength. Eleven different forms of the gene region were identified but, intriguingly, one of them - allele 334 - which was carried by 40% of the participants, was strongly linked to poorer "Partner Bonding Scores" (PBS). Men with two copies of the gene (one from their father and one from their mother) were also half as likely to be married (favouring co-habitation) and twice as likely to have faced marital crisis or the threat of a divorce in the previous 12 months (34%) compared with the men with one or no copies of the 334 allele, only 16% of whom reported marriage difficulties. This suggests that what goes for the voles also goes for humans, but may also have relevance to our understanding of certain other aspects of human social behaviour and development including altruism and autism, both of which have been linked to changes in this same gene.