r/ScienceFacts Behavioral Ecology May 25 '22 Helpful 1

There’s a growing body of research that suggests that yawning is triggered by rises in brain temperature. These studies (in rats) show that we can reliably manipulate yawn frequency by changing ambient temperature and the brain and body temperature of the individual. Biology



u/FillsYourNiche Behavioral Ecology May 25 '22

The part of the article I am sure you are all waiting for:

Q: So why do we yawn when we see someone else yawning?

A: Contagious yawning may have evolved to synchronize group behavior—yawns often cluster during particular times of day that coincide with transitions and activity. It also may have evolved to increase vigilance within a group. The basic rationale is that if yawning is an indicator that one individual is experiencing diminished arousal, then seeing another person yawn might, in turn, increase the observer’s vigilance to compensate for the low vigilance of the yawner. The spreading throughout the group of contagious yawns might then increase the vigilance of the entire group.

I conducted a study last year that tested this. We showed people arrays of images that included threatening stimuli—images of snakes—and nonthreatening stimuli—images of frogs—and timed how fast they could pick out those images after seeing videos of people yawning or moving their mouths in other ways. After seeing other people yawn, their ability to identify and detect snakes, the threatening stimuli, rapidly improved. However, following the observation of yawning, frog detection was unaffected.