You can tell a lot about a person from their body. And I don’t just mean how many hours they spend at the gym, or how easy it is for them to sweet-talk their way out of speeding tickets. For the past several decades researchers have been studying the ways in which the body reveals properties of the mind. An important subset of this work has taken this idea a step further: do the ways our bodies relate to one another tell us about the ways in which our minds relate to one another? Consider behavioral mimicry. Many studies have found that we quite readily mimic the nonverbal behavior of those with whom we interact. Furthermore, the degree to which we mimic others is predicted by both our personality traits as well as our relationship to those around us. In short, the more empathetic we are, the more we mimic, and the more we like the people we’re interacting with, the more we mimic. The relationship between our bodies reveals something about the relationship between our minds.
The bulk of this research has made use of clever experimental manipulations involving research assistant actors. The actor crosses his legs and then waits to see if the participant crosses his legs, too. If so, we’ve found mimicry, and can now compare the presence of mimicry with self-reports of, say, liking and interpersonal closeness to see if there is a relationship. More naturalistic evidence for this phenomenon has been much harder to come by. That is, to what extent do we see this kind of nonverbal back and forth in the real world and to what extent does it reveal the same properties of minds that seem to hold true in the lab?
A recent study conducted by Ivan Norscia and Elisabetta Palagi and published in the journal PLoSONE has found such evidence in the unlikeliest of places: yawns. More specifically, yawn contagion, or that annoyingly inevitable phenomenon that follows seeing, hearing (and even reading) about another yawn. You’ve certainly experienced this, but perhaps you have not considered what it might reveal to others (beyond a lack of sleep or your interest level in their conversation). Past work has demonstrated that, similar to behavioral mimicry, contagious yawners tend to be higher in dispositional empathy. That is, they tend to be the type of people who are better, and more interested in, understanding other people’s internal states. Not only that, but contagious yawning seems to emerge in children at the same time that they develop the cognitive capacities involved in empathizing with others. And children who lack this capacity, such as in autism, also show deficits in their ability to catch others’ yawns. In short, the link between yawning and empathizing appears strong.
Given that regions of the brain involved in empathizing with others can be influenced by the degree of psychological closeness to those others, Norscia and Palagi wanted to know whether contagious yawning might also reveal information about how we relate to those around us. Specifically, are we more likely to catch the yawns of people to whom we are emotionally closer? Can we deduce something about the quality of the relationships between individuals based solely on their pattern of yawning? Yawning might tell us the degree to which we empathize with, and by extension care about, the people around us.