Enjoying marital bliss? If so, you can thank your DNA, at least according to a study from the University of California, Berkeley. Researchers have found that a gene involved in the regulation of serotonin can predict how much our emotions affect our relationships, and thus how good or bad the relationship would be. “An enduring mystery is, what makes one spouse so attuned to the emotional climate in a marriage and another so oblivious?” said senior author and psychologist Robert W Levenson. “With these new genetic findings, we now understand much more about what determines just how important emotions are for different people.” The team found a link between relationship fulfillment and a gene variant, or ‘allele’, known as 5-HTTLPR. All humans inherit a copy of this gene variant from each parent, they said. Study participants with two short alleles were found to be most unhappy in their marriages when there was a lot of negative emotion, such as anger and contempt, and most happy when there was positive emotion, such as humor and affection.