Yawning is a mysterious reflex. Sometimes we do it because we're tired. Other times, we yawn when someone else does. A sizeable body of work suggests that empathy underlies the phenomenon of catching yawns, and it seems that people who engage in more perspective taking (i.e., the ability to get inside someone else's head and understand what they're feeling) are more susceptible to catching the yawns. On the flip side, people with higher levels of psychopathic traits showed more resistance to catching yawns in one study. Despite knowing that empathy and yawning are linked, we don't really know why.
Last year, in attempts to figure out the underpinnings of contagious yawning, researchers from the State University of New York at Oneonta looked at the impact of oxytocin, aka the love hormone, on contagious yawning. Oxytocin is released during all sorts of lovey-dovey experiences, including emotional bonding and getting sexy. Also, it appears to facilitate empathetic behavior in men.
Because yawning and oxytocin have both been linked to empathy and perspective taking, researchers wondered if people would exhibit more contagious yawning after taking an oxytocin nasal spray. While they struck out hard with their prediction, they observed a different, similarly neat phenomenon: Taking oxytocin didn't correspond to more yawning, but it did seem to enhance awareness of the habit and its social implications.
For the study, 60 male college students self-administered either synthetic oxytocin nasal spray or a placebo saline spray. Researchers excluded women from the experiment because they didn't know how hormonal fluctuations (based on their menstrual cycles) would interact with the oxytocin. Researchers tested participants' susceptibility to contagious yawning by showing them video clips of people making facial expressions including yawning. (The video sessions were recorded.) Afterwards, participants answered questions about their yawning behavior and urge to yawn during the video.
About one-third of participants (across both groups) yawned during the video sessions. So, snorting the love hormone didn't spark uncontrollable yawning fits. But, the oxytocin group did try to suppress their yawns more than the other group did. At least, the evidence pointed that way.
On the questionnaires, oxytocin-takers reported yawning less often than they felt the urge to yawn, whereas the placebo group basically yawned when the urge struck them. And, recordings of the video sessions showed that the oxytocin group waited 40 seconds longer (on average) than control-group members to yawn in response to video clips. Oxytocin-takers also exhibited more physical signs of yawn-suppression, such as covering their mouths with their hands and clenching their jaws, and fewer signs associated with yawning, such as sighing and stretching.
The implications? "Since yawning in the presence of others is considered rude and often thought of as a sign of boredom or disrespect, and oxytocin has been shown to enhance social awareness, we interpret these findings as oxytocin producing a greater awareness of the social stigma related to the behavior."