There are few things as simple and ancient as a yawn. And yet, science is still not entirely clear about its physiological and social functions. There is, yes, a certain consensus on who yawnunder what circumstances and several hypotheses about whether doing so brings an advantage evolution for survival.
For now, it’s a very common thing. And not just among sleepy people. According to a recent review published by the biologist Andrew Gallup in the scientific journal Animal Behavior, yawning “is a common pattern of virtually all vertebrate species, obviously including Homo Sapiens.” According to this researcher New York Polytechnic Institute, “there is a growing consensus about the physiological functions that spontaneous yawning fulfills, activating circulation in the cerebral blood vessels and facilitating a slight cooling of the brain,” he noted. “But what we don’t know as much about is how it alters the cognitive process and the behavior of those who observe the yawner.” The majority position proposes that the famous “contagion” could be an element that would help synchronize the patterns of collective activity.
YAWN FUNCTIONS
The most recent studies suggest that it plays a role during a change in neuronal state, exciting its functioning. This theory makes it easier to understand why this physical externalization is usually associated with a moment of behavioral transition: the typical ones are from sleeping to waking up, waking up to sleeping and also in the fluctuation of attention to boredom. On the other hand, there is evidence that yawning helps decrease brain temperature which, in turn, It would help improve alertness and the speed of mental processing.
Another element with which it is associated in all species is a stressful situation. Its frequency tends to increase in times of stress, a situation that causes mental changes, excitement and elevation of body temperature. And increases in yawning frequency have been documented during stressful events such as in a group of skydivers before starting their first jump alone or in Olympic athletes in the moments before their competition.
Something to keep in mind is that the famous “contagion” of yawning between individuals who look at or hear each other is a behavior that has only been found in animal species with strong social behavior. To explain it there various hypotheses. Some propose that it is an indicator that rreflects empathy, where you accompany with your own yawn another individual helps consolidate a group. But this has not always been proven and other hypotheses suggest that “contagious yawning” may have been an evolutionary tool to synchronize the behavior of a group at significant moments that coincide with activity transitions. For example, at the moment when it is important to increase vigilance. In other words, if yawning is a visible indicator that one member is experiencing a decrease in her neural activity and another perceives it, the “infected” could yawn and thus improve their own vigilance and compensate for the drop in reflexes of the original yawner.
