Did you know that the video game Rock Band® can be used as a tool for social bonding? And that empathy causes us to feel pain more strongly? Pretty strange, huh? Both the product of social psychology research, these two findings have allowed researchers to show that empathy cannot be felt in the presence of a stranger.

These results were first found in mice. Mice feel even more pain when confronted with a painful (but nevertheless moderate) stimulus if this stimulus is introduced in the presence of a familiar mouse, such as a cage mate, as compared to an unfamiliar mouse.

Naturally, the researchers wanted to know if the same effect could be observed in humans. This time, students were asked to place their arms in ice-cold water, which served as the painful stimulus. This was done in the presence of a stranger and in the presence of a friend. Just like the mice, the students felt more pain in the presence of someone familiar.

But it doesn't end there. Pairs of students who had never met were asked to play the video game Rock Band® together for fifteen minutes. Rock Band® is a music video game where players have to create a virtual rock group using devices to stimulate different instruments, likes drums or guitar. The ice–water experiment was then repeated using the subject’s partner from the game. And this time, empathy appears to have resurfaced, as participants felt the same amount of pain in their partner’s presence as they did in the presence of a friend.

These weren’t exactly the results the team had expected. "It would seem like more pain in the presence of a friend would be bad news, but it's in fact a sign that there is strong empathy between individuals -- they are indeed feeling each other's pain," said Mogil, one of the study's co-authors. "It turns out that even a shared experience that is as superficial as playing a video game together can move people from the 'stranger zone' to the 'friend zone' and generate meaningful levels of empathy."

These fascinating results represent yet another step toward understanding the social mechanisms that operate between individuals. It also provides new data toward understanding psychological disorders related to a lack of empathy, such a certain forms of autism and psychopathy.