It turns out heartbreak really does hurt. That’s the word from Dr. Ethan Kross, a professor of psychology at the University of Michigan. He recently led a study into why people feel physical pain after a breakup – even though there’s been no physical damage. He found that as far as the brain is concerned, emotional and physical pain are the same thing!

In the study, Dr. Kross recruited volunteers who had been through a breakup within the previous six months. None of the volunteers had a history of chronic pain, or mental illness, so the only pain in their lives was emotional.

In the first part of the experiment, the volunteers were touched with a hot probe while lying inside an MRI brain scanner. Dr. Kross says the probe wasn’t hot enough to burn, but it was hot enough to hurt if you didn’t pull away. Then, all the volunteers were shown photos of their ex-girlfriends or boyfriends, and they were asked to think about their breakups.

So what happened? In both tests, scans revealed that the same areas of the brain lit up. Basically, the brain was processing physical pain and emotional rejection in the exact same way.

Dr. Kross suspects this may be a survival mechanism that’s been hard-wired into our brains for centuries. His thinking is that back in the days when our ancestors lived in caves, people needed to stick together to find food, build shelter, and improve their odds staying alive! Back then, we knew that being excluded from the group was one of the most dangerous things that could happen. So that’s why Dr. Kross believes we quickly learned to associate the emotional pain of being alone with the real pain we might feel from being killed.