Nervous Laughter, Tears of Joy

In Stanley Milgram's famous obedience experiments, the subjects, called "teachers," were instructed to shock the "learners" for every wrong answer. The learners, confederates in the study, were not actually shocked, of course, but the teachers believed they were -- and they even heard faked cries of pain to add authenticity. Most of the subjects showed signs of distress, as one would expect, and some were extremely agitated. But it's said that some of the subjects laughed when they heard the screams.

We call this nervous laughter -- incongruous emotional displays like chuckling uncontrollably at a funeral or some other somber or upsetting event. Everyone has witnessed or experienced such discordant expressions, though we're probably more familiar with incongruous negative displays -- crying at a wedding, growling at the sight of a newborn baby, screaming in the presence of a teen idol.

Are these inappropriate emotional expressions simply embarrassing aberrations? What psychological purpose could they serve? Yale University psychological scientist Oriana Aragon and her colleagues have been studying this phenomenon in the laboratory, and they suspect that such displays -- as uncomfortable as they can be -- might actually play an important role in overall emotional regulation. That is, when we are at risk of being overwhelmed by our emotions -- either positive or negative -- expressing the opposite emotion can have a dampening effect and restore emotional balance.

The scientists based their reasoning on a widely accepted model of emotion. Think about someone winning a $1 million lottery prize. Normally, the winner mentally appraises such an event, and in this example, decides that winning the lottery is a very good thing. This appraisal leads to intense happiness and positive verbal expression: "Oh, my god. I can't believe it!" Often, this is all there is to it, but in some cases, there is also an expression of sadness -- a facial expression, tears -- that does not seem to fit with the experience.

Aragon and her colleagues believe that people have emotional limits. When we sense that our escalating sadness or joy is reaching an unmanageable limit -- that our bodies are about to be overwhelmed physiologically -- this perception triggers an incongruous emotion to balance things out. At least that's the theory, which the scientists have been exploring in their studies.

In one study, for example, they focused on cute babies. They morphed photographs of babies, so that some were more infantile than others -- larger eyes, cheeks and foreheads, and smaller noses, lips and chins. Male and female volunteers, about 30 years old on average, reacted to the photos, and as expected, they were more positive about the more infantile babies. They were also more likely to report being overwhelmed by positive feelings when looking at the younger babies. Volunteers also described their feelings about the babies: I want to hold it! I want to protect it! I feel like pinching those cheeks! I want to eat it up! And so forth. The scientists wanted to get an overall measure of "playful aggression" in volunteers' responses to cuteness.

The results confirmed the scientists' expectations. Participants wanted to care for the infantile babies more than the older babies, and they also reported more aggressive expressions toward the younger babies. They also found, as hypothesized, that the function of the pinching and growling and other playful aggression is to regulate overwhelmingly positive feelings toward the babies -- to help people cope with their intense emotions.

Although this study focused on cute babies, the scientists also found that individuals react with mixed emotions, or they don't, regardless of the situation or the precise emotion. That is, the people who want to pinch babies' cheeks also tend to cry when reuniting with a loved one.

The scientists conducted several studies of incongruous emotions, described in a forthcoming issue of the journal Psychological Science, all supporting the general idea that these embarrassing displays help with self-regulation. Just how this occurs is unclear. It may be that secondary emotions work through facial or postural cues to trigger a physiological shift away from an intense emotion. Or it's possible that when people feel intense positive emotions, they express negativity to give important events the appropriate gravitas.

Follow Wray Herbert's reporting on psychological science in The Huffington Post and on Twitter at @wrayherbert.