How important is it to consider a romantic partner’s genetic profile before getting married?
It is logical to think that genetic factors may underlie many traits already used by matching sites – like personality and empathy – which many assume could promote initial chemistry and long-term potential in specific couples. So it is perhaps not surprising that there are now websites that combine genetic testing and matchmaking.
But does matching intimate partners on the basis of specific genes have any scientific foundation? Studies have shown that genetically identical twins, raised separately, rate the overall quality of their marriages similarly, suggesting some enduring genetic contribution to marital life. However, the specific genes that are relevant to marriage, and why, remain a mystery.
As such, predicting marital compatibility on the basis of specific combinations of genetic profiles rests on tenuous scientific footing. Currently, researchers are just beginning to identify the genes that may be associated with marital bliss and through what processes.
Why study the effects of genes on marriage?
As a scientist and clinical psychologist, I have a longstanding interest in identifying the factors that contribute to a happy marriage, such as how couples manage conflict. My interest in exploring genetic determinants, however, developed more recently.
Genes are segments of DNA that encode a particular trait. A gene can take on various forms called alleles, and the combination of the two alleles inherited from both parents represent one’s genotype. Differences in genotype correspond to observable differences within that trait across individuals.
Though genes underlie individual differences in a broad range of characteristics believed to be relevant to marriage, I am specifically interested in the oxytocin receptor (OXTR) gene. Oxytocin, sometimes referred to as the “love” hormone, appears to play a significant role in emotional attachment. For example, oxytocin floods a new mother at the birth of a child and it spikes during sex. Therefore, I reasoned that the gene that regulates oxytocin, OXTR, might be a good one to study in the context of marriage, as it is frequently implicated in how we become attached to other humans. Moreover, OXTR has been associated with a range of phenomena linked to human social behavior, including trust and sociability.
Of greatest interest to me is that the OXTR gene has been linked with physiological responses to social support and traits believed to be critical to support processes, like empathy. Considered alongside findings that the quality of social support is a major determinant of overall marital quality, the evidence implied that variations on the OXTR gene could be tethered to later marital quality by influencing how partners support each other. To test this hypothesis, I pulled together a multidisciplinary team of scientists including psychologists with additional expertise in marital research, a geneticist and a neuroendocrinologist specializing in oxytocin.
Together our team recruited 79 different-sex married couples to participate in our study. We then asked each partner to identify an important personal problem – unrelated to the marriage – to discuss with their spouse for 10 minutes.
These discussions were recorded and later coded according to how each partner solicited and provided “positive” support by scoring elements like problem-solving and active listening. Couples responded separately to several questionnaires including a measure of perceived quality of the support they received during the interaction. Each person also provided saliva samples that our team analyzed to determine which two alleles of the OXTR gene each person carried.
Genetic variation and marital quality
Based on prior evidence, we focused our attention on two specific locations on the OXTR gene: rs1042778 and rs4686302. As expected, higher quality social support was associated with marital quality. Also, genetic variation at each OXTR site for both husbands and wives was linked with how partners behaved during the support discussions.