US researchers have identified a genetic association with feelings of happiness and security within a marriage.
The team at Yale University in New Haven, Connecticut, examined a variation within the oxytocin receptor gene previously shown to be associated with differences in social behaviours. They found that if one spouse within a couple had a variant, known as the GG genotype, the couple reported greater feelings of security and satisfaction than couples without this variant.
'This study shows that how we feel in our close relationships is influenced by more than just our shared experiences with our partners over time,' said Dr Joan Monin from the Yale School of Public Health, who led the research. 'In marriage, people are also influenced by their own and their partner's genetic predispositions.'
This study focused on 178 heterosexual, married couples, aged between 37 and 90, who were asked about their sense of marital satisfaction. Participants provided saliva samples for researchers to analyse their gene variants.
Individuals who had the GG genotype displayed higher rates of emotional stability, sociability and empathy. The researchers found that if one spouse in a couple had the GG genotype, their own marital satisfaction was greater, but there was also a 'partner effect' with their spouse reporting greater satisfaction. People who have the GG genotype seem to have less anxious attachment, which is a type of relationship insecurity that forms from past relationships and behaviours.
Researchers estimate that about four percent of the variance in relationship satisfaction stems from this gene variant. This research is thought to be the first to examine this gene variant and its role in the quality of a marriage.
The study was published in PLOS ONE.