McGill University Psychology Professor Jeffrey Mogil, graduate student Dale Langford and colleagues at the Pain Genetics Lab, discovered mice familiar with each other and able to see one another in pain were more sensitive to pain than those tested alone.

The results — which for the first time show a form of emotional contagion between animals — shed light on how known social factors play a role in pain management.

The researchers say their findings are not only unprecedented in what they tell us about animals, they may ultimately be relevant to understanding pain in humans.

Since we know that social interaction plays an important role in chronic pain behavior in humans, Mogil said, then the mechanism underlying such effects can now be elucidated: why are we so affected by those around us?

The research was published online June 29 in the Journal Science.