The secret to a happy marriage lies in the genes, scientists have discovered, as new research finds a predisposition not to be anxious is the key to marital stability.
A study by Yale University which examined 178 married couples found a gene trait in common among those whose marriages were more secure.
Researchers focused on the role of a genetic variation that affects oxytocin, a hormone that plays a role in social bonding, known as the GG genotype.
The found that once factors such as physical attraction and shared values had been taken into account, the genotype explained what those who felt themselves secure in their marriages had in common.
"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 Professor Joan Monin, who led the study.
"In marriage, people are also influenced by their own and their partner's genetic predispositions."
The researchers also found that people with the GG genotype reported less anxious attachment in their marriage, which also benefited their relationship.
Anxious attachment is a style of relationship insecurity that develops from past experiences with close family members and partners over the life course, and is associated with diminished self-worth, high rejection sensitivity, and approval-seeking behavior.
The study found that an individual's GG genotype and their partner's GG genotype together account for about 4 per cent of the variance of marital satisfaction.
The authors said that although this percentage appears small, it is a significant influence considering other genetic and environmental factors to which couples are exposed.
Each participant completed a survey about their feelings of marital security and satisfaction and also provided a saliva sample for genotyping. The study is published in the journal PLOS ONE.
