In 2009, a study led by psychologist C. Nathan DeWall at the University of Kentucky investigated the effect of analgesics (physical pain-killers) on emotional pain. The first experiment involved one group of participants receiving a dose of 1,000mg of acetaminophen (standard over the counter paracetamol) per day, and another group taking placebo tablets. Each volunteer then reported the levels of emotional hurt they experienced. The researchers found that over time, participants taking the acetaminophen generally reported lower levels of emotional hurt compared to those who had only been administered the placebo. A second experiment expanded upon these findings, with the participants receiving an increased daily dose of 2,000mg of acetaminophen for three weeks before undergoing tests involving functional magnetic resonance imaging. Once inside the fMRI scanner, participants played a computer game designed to simulate situations of social rejection. Their neural responses were recorded, and both brain regions which process emotional and physical pain were observed to be less active when compared to the responses of placebo subjects. These results suggested that the analgesic dulled the brain’s response to social rejection, indicating a link between how the brain processes physical and emotional pain.
This link was further compounded by a study published this year in the March journal of Proceedings of the National Academy of Sciences, which established that two regions of the brain previously known only to process the sensation of physical pain are also activated when the subject is in emotional distress. Again, functional magnetic resonance imaging was used to observe brain activity whilst participants were presented with a photograph of former partners and asked to focus on their feelings brought about by being rejected by their ex. The same brain networks activated by physical pain also lit up under these circumstances, indicating that little neurological distinction is made between these two types of pain. As psychology professor Ethan Kross, the lead researcher at the University of Michigan, says: ‘heartache and painful break ups are “more than just metaphors”. Professor Alexander, the director of the Aberdeen Centre for Trauma Research, was unsurprised by the link between physical and emotional pain. Having led the psychiatric team who were the first to deal with the Piper Alpha oil-rig disaster (where 167 men were killed by an explosion) and who have since been involved in helping survivors of disasters like the Iraq war and the Asian tsunami, Alexander has had much experience with those who have suffered severe emotional distress. “If you listen to people who are damaged emotionally, they will often translate their pain into physical similes: ‘My head is bursting, my guts are aching’ and so on. The parallel is very strong.”
So why are physical and emotional pain so closely linked? One explanation stems from the idea that social attachment to others is crucial to our survival: humans are much safer in groups than as individuals when in dangerous situations. Because being rejected from a social group is painful, we avoid it. Furthermore, just as physical pain serves as a warning not to touch a hot stove, emotional pain can warn us to avoid unfaithful partners or destructive friendships. And so while emotional pain physically hurts, it seems to do so for a good reason.