Why yawning is contagious, study finds it could have evolved to increase alertness in a group

Have you ever wondered why watching someone yawn instantly triggers a similar urge to open your mouth? While scientists have figured out the physiological purpose of yawning, why it’s so contagious in social animals has left them baffled. According to Andrew Gallup, an evolutionary biologist at the State University of New York Polytechnic Institute and author of the paper, yawning could be a way for groups of animals to get in sync with each other. others and coordinate group behaviors.

We usually yawn when going from one state of activity to another, which can be either waking up from a deep sleep or going to bed after a tiring day. Yawning has long been believed to be a way to exhale carbon dioxide and replenish oxygen. But, now it seems yawning is more about moderating blood temperature to cool the brain. A study, published in the journal Animal Behavior, has shed some light on contagious yawning.

Regarding successive contagious yawning between individuals, Gallup explained that this behavior could have evolved to increase alertness within a group. The idea is that if yawning indicates that a person is feeling drowsy, then watching them yawn can alert other members of the group. This compensates for the low alertness of the yawning person and thus increases the overall alertness of the group.

To elucidate the idea, Gallup conducted a study last year. He showed people multiple images that included threatening stimuli such as pictures of snakes and non-threatening stimuli such as pictures of frogs. People were first taken to see videos of yawning and then the footage was shown to them. Gallup then tested its ability to select images from the image array.

He observed that after seeing people yawn, one could more effectively detect threatening stimuli or images of snakes. However, people’s ability to detect the frog’s image remained unchanged, Science Magazine reported.