Genetic factors may influence an individual's likelihood of experiencing relationship breakdowns, according to a new study. Researchers examining DNA from thousands of participants in the Norwegian Mother, Father and Child Cohort Study found that certain genetic traits are associated with more stable relationships, while others are linked to a higher risk of separation.
The study analyzed "polygenic scores," which combine the effects of thousands of genetic variants associated with different traits. The findings indicate that individuals with higher genetic scores for educational attainment, subjective wellbeing, and a later age at first birth were less likely to see their relationships end. Conversely, those with higher genetic scores linked to smoking and an earlier sexual debut showed a modestly increased risk of separation.
Lead researcher Ruth Eva Jørgensen, a sociologist at the University of Oslo, emphasized that there is no single "divorce gene." Instead, she explained, a multitude of small genetic differences can collectively influence a person's predisposition towards relationship stability or breakdown. "Our destiny does not lie in our genes, but if a relationship were a jigsaw puzzle, our genetics would make up some of the pieces that can influence the risk of a breakup," Jørgensen stated.
In a surprising finding, individuals with a higher genetic tendency toward neuroticism were found to be slightly less likely to experience a breakup. Researchers suggest this may be because the need for security provided by a relationship can outweigh the potential challenges associated with anxiety or vulnerability.
To account for environmental influences, such as family upbringing, the researchers compared siblings, who share similar environments but inherit different genetic combinations. When genetic differences between siblings correlated with different relationship outcomes, it strengthened the evidence for DNA's role.
Overall, common genetic variants were estimated to explain approximately nine percent of the differences in women's likelihood of relationship breakdown and about three percent in men. Jørgensen stressed the continued importance of environmental factors, noting that genetic predispositions can manifest differently depending on life experiences, opportunities, and relationships encountered.
The study's findings suggest that while genetics may slightly influence the odds, the success of a relationship ultimately depends heavily on the choices individuals make, the partners they select, and the lives they build together. Jørgensen published her findings as part of her dissertation, titled ‘Partnership Dissolution, Intergenerational Consequences and Partner Influence. A Socioeconomic Perspective on Family Dynamics.’