Why a breakup feels like a punch in the stomach

We’ve all been there. A lover, out of the blue, says it’s over. Suddenly there’s a stabbing sensation in the chest, or a wrenching of the gut. Though there’s been no physical damage, it really hurts.

Scientists now know why we feel as if we’ve been physically wounded when the hurt is emotional. A study published in the Proceedings of the National Academy of Sciences found that the same brain areas spark, whether we’re experiencing physical pain or deep emotional distress.

“It means that the expression, ‘My feelings are hurt,’ may be more than just a metaphor,” says the study’s lead author, Ethan Kross, an assistant professor in the psychology department at the University of Michigan.

Earlier scanning studies had shown that the brain doesn’t see any difference between the negative emotions elicited by physical and emotional pain.

But Kross and his colleagues wondered if they could explain the actual physical pains people feel when they experience rejection.

The researchers rounded up 40 people who had been dumped by a lover within the previous six months – so the pain of rejection was still fresh.

For the first part of the experiment, the 40 were touched with a hot probe while they lay in a brain scanner. The probe wasn’t hot enough to burn, but it did hurt. “It’s akin to holding a really hot cup of coffee without the little guard to protect your hand,” Kross says. “You wouldn’t want to do it forever, but it doesn’t burn you.”

For the next part of the experiment, study volunteers were again scanned, but this time they were asked to concentrate on a photo of their ex-lover and to think about the break-up.

The same brain areas lit up whether people were being touched by the hot probe or they were mentally reliving their rejections. Some of those areas were the ones that are involved in processing negative emotions, but other areas -- those that help us sense physical pain -- also lit up.

Kross suspects we’ve evolved to feel actual pain at separation because way back when humans were on the savannah they needed to stay connected. Being alone was dangerous -- you’d be more of a target for the wandering saber-toothed tiger.

“One of the most negative things to happen, in terms of survival, is being excluded from the group,” Kross says. “So the feeling of physical pain would be a powerful cue to pay attention to what you’re doing.”