Study co-author DeWall of the University of Kentucky stresses that the findings do not make a case for taking Tylenol to soothe feelings of loneliness or hurt. That was done to demonstrate that in processing pain, the brain appears primed to respond — or not to respond, when an analgesic is present — pretty much the same to social pain as it does to physical pain.
It's a point that the University of Toronto's Geoff MacDonald, another of this field's pioneering researchers, knows well. MacDonald and his colleagues have shown that the trajectory of hurt feelings in the wake of a social insult looks very much like the body's response to physical injury: Initially, a surge of stress hormones is released, readying the body to flee or stand and fight. During this phase, the injured often report feeling numb and, despite broken bones or a shattered skull, can walk and talk. After this surge of energy dissipates, the sensation of pain generally sets in.
In MacDonald's experiments, subjects also report feelings of numbness in the immediate wake of social rejection. For several minutes, they are less, not more, sensitive to feelings of social pain. But as the initial shock of the insult passes, subjects describe powerful feelings of hurt — even when the social slight they have endured may seem minor.
This parallel, says MacDonald, suggests that piggybacking the brain circuits for social pain onto ones for physical pain was not merely an accident of evolutionary thrift: It's useful. It helps us to focus on the essential task of binding up torn social fabric, of nurturing our relationships with others after the immediate threat of expulsion from the group has passed. It has helped make us the uniquely social creatures that we are.
"This lingering sense of pain draws our attention to the experience," MacDonald says. "We ask, 'Why did it happen this way? What was it about my behavior, or their behavior, that caused the breach, and how might I behave differently next time?' And that's very functional."