A quiet, shy-looking student made me cry. It wasn't when I heard about his tragic life - abandoned at 3, escaping an abusive orphanage at 5, then somehow eking out a living alone on the streets - but when he started singing with that earnest, yet surprisingly powerful voice. The whole thing left me wiping away tears. And from the online video clip, it seemed most of the judges and audience members who saw Choi Sung-Bong at that Korean talent show were also crying out of happiness for him.
It also struck me as quite odd. Everyone looked so happy for this guy and his new-found potential. So why were they weeping? Crying is so strongly associated with emotional pain, yet it also occurs in even the most positive situations. Proud parents become teary-eyed at their kid's graduation. Steely-nerved athletes get choked-up when talking about winning a final match.
One possibility is that happy crying really isn't that different from sad crying. What both have in common is a period of intense emotional arousal. Indeed, brain regions associated with emotional arousal, including areas of the hypothalamus and basal ganglia, are connected to a section of the brainstem called the lacrimal nucleus that stimulates tear production.
Given these connections, it is tempting to think that crying is the result of our emotions reaching some kind of boiling point. But evidence suggests instead, that crying may occur only after the worst is over. By this view, our "happy" tears when reunited with a loved one may have more to do with relief from our anxious worrying while they were away than the reward of them now being with us.
Either way, tears and vocal sobbing can result in greater feelings of sympathy and empathy by others. So happy crying can help to strengthen mutual bonds between people, just as sad crying can provide important signals that a person is in need of help or comfort.
The tears themselves may also help others know how to respond. A recent psychology experiment, for example, found that it is much easier to recognize a sad facial expression if tears are present in the image. When the tears were digitally removed, the same images were increasingly confused with other expressions, such as awe or puzzlement. Perhaps those crying for Choi Sung-Bong looked odd to me because of the mismatch of happy-signalling smiles and sad-signalling tears.
Tears can also affect the behaviour of others in ways they are not even aware of. When you're crying, the last thing you need is to worry about an unwanted sexual advance. New research suggests that chemical signals in emotional tears help to prevent this. In one study, a cotton pad soaked in either a sad woman's tears or a saline solution was placed under the noses of male participants. Although the different pads smelled the same, brain scans revealed that sniffing the one with tears resulted in less activity in regions of the hypothalamus associated with sexual arousal. The tear exposure caused images of female faces to be rated as less sexually attractive, and even produced a dip in the men's testosterone levels.
Thus, whether a period of emotional instability ends with a smile or a frown, our tears may ensure we benefit from appropriate social interactions. And the benefits for mood and emotional balance can be substantial. But research also suggests that this is all lost when stigma or fear of appearing vulnerable prevents one from feeling comfortable crying in front of others.
So the next time your lip starts to quiver, find a safe shoulder to cry on and go with the flow.
Mark Fenske, co-author of The Winner's Brain: 8 Strategies Great Minds Use to Achieve Success , is an associate professor in neuroscience at the University of Guelph.