The hurt of social rejection or exclusion is emotional. But there must be a reason why we so often experience it -- and talk about it -- as if it were a physical pain. One feels "burned" by a partner's infidelity, "wounded" by a friend's harsh words, "heartache" when spurned by a lover.
It turns out, there is a good reason we use such terms: The same circuits in the brain that are responsible for processing physical pain are also called into play when one feels the sting of social rejection. And a new study finds that people who have a rare variation of a gene that programs cells in those circuits are acutely sensitive to physical pain and to the hurt that comes from social rejection.
One class of brain cells that plays a key role in physical and social pain are mu opioid receptors. They're best known for their role in dampening pain when an opiate drug or one of the body's own painkillers appears in their midst. But they are at work when we seek out or feel pleasure as well. The gene OPRM1 helps govern the function of these receptors. Scattered through the family of man are several variants of OPRM1.
Research already has shown that those who have the rarest variant of that gene are keenly sensitive to physical pain. The latest study suggests that this same population reacts strongly when, in an experimental situation, they are drawn into a group and then excluded from its activities. The study was published online earlier this month in the Proceedings of the National Academy of Sciences.
While the social-sensitivity variant of the OPRM1 gene appears rarely in Caucasian populations tested to date, it appears to be far more common in those of Asian descent. That may offer some insight into the many rituals, customs and social conventions that govern interaction in many Asian cultures: If exclusion is painful, adherence to clearly delineated rules would help prevent such discomfort.