Yawning is the action of opening the mouth to take a long, deep breath. It is commonly associated with drowsiness and boredom. However, recent studies have claimed that yawning might be a way in which our body is trying to accomplish important functions.
Yawning is commonly triggered by drowsiness or boredom. Drowsiness occurs by stimulating the sleep-generating system when the mind has to make an effort to maintain contact with the external environment. Boredom occurs when the main source of stimulation in a person’s environment is no longer able to sustain their attention.
Researchers have claimed that a potential physiological function of yawning could be the regulation of temperature in the brain. It has been postulated that yawning might cool down the brain when its temperature increases. A shred of evidence for this proposition comes from research in which the prelimbic cortical brain temperature recordings were continuously monitored in rats (Rattus Norvegicus), during the three minutes before and after yawning. Cortical temperatures were seen to be significantly higher until the onset of yawn, in which temperatures fell and returned to baseline only three minutes after yawning.
The frequency of yawning due to the temperature of the brain was investigated in an experiment conducted by Gallup and Gallup. In the experiment, participants watched videos of humans yawning, with the participants either having a war or cold ice pack on their forehead. It was observed that the person with the warm pack yawned more frequently than the one with the cool pack. This showed that the physiological consequences of yawning are analogous to those that are needed to effectively cool the brain, such as an increase in the peripheral and cerebral blood flow.
So, how does this answer the question of why humans yawn? Well, we do so to serve a social function (to communicate boredom) and a physiological function (regulation of body state). Yawning is not just a sign of boredom or tiredness—it serves both a social function and a physiological one, helping regulate our brain and body. So, the next time you yawn, remember that your brain is hard at work.
