Are some people genetically predisposed to stay happily married? Researchers at UC Berkeley have found a major clue in our DNA. Robert Levenson and his team have found a link between relationship fulfillment and a variation of the serotonin transporter gene - referred to as the "short allele."
Adorable video on DNA & long term relationships. I love how the scientist explains that short-allele (serotonin transporter) folks are just more sensitive to emotion and not defective.