Exploring the Reasons Behind Yawning: A Look into Its Spreadability
Yawning, a common human behaviour, has long puzzled scientists due to its diverse and seemingly contradictory explanations. Recent research suggests that yawning serves various physiological, neurological, and social functions.
One of the main theories revolves around **brain cooling or thermoregulation**. Yawning may help cool the brain to optimise its performance, particularly during thermal stress or before sleep. This is achieved through deep inhalation, which facilitates airflow and changes in blood flow that reduce brain temperature [2][5].
Another function of yawning is to **increase alertness and arousal**. Yawning is linked to an increase in heart rate and stimulation of alertness. It may serve as a mechanism to keep the brain awake and ready, especially when drowsy or transitioning between sleep and wakefulness [2].
Yawning also plays a role in **social communication and empathy**. Contagious yawning, a phenomenon where yawning spreads from one person to another, suggests a social role. Contagious yawning is more common in social or pack animals and may function as a nonverbal communication signal to synchronise group behaviour and express empathy or social bonding [1][2][4].
While some older theories proposed that yawning increases oxygen intake and expels carbon dioxide, this explanation has largely fallen out of favour, as studies found no direct correlation between oxygen levels and yawning frequency [3][5].
Excessive yawning can sometimes signal underlying health issues and may warrant medical attention if it is frequent and unexplained. Possible causes include neurological conditions, medication side effects, sleep disorders or fatigue, and stress and anxiety [4][5]. If yawning is accompanied by other symptoms like fatigue, muscle weakness, or persistent drowsiness, consulting a healthcare professional is advisable.
In summary, yawning serves multiple purposes, including brain cooling, maintaining alertness, and social communication. Excessive yawning can be a sign of health issues and should be evaluated if persistent or associated with other symptoms.
Sleep cycles, boredom, and stress are associated with temperature fluctuations in the brain. If you want to stop yawning, you can try taking deep breaths, moving around, cooling down, or stimulating your body. Yawning can cause tearing up, which releases heat, potentially aiding in brain temperature regulation.
Dr. Donald Ford, a family medicine physician, suggests that yawning could be a way for the body to regulate its temperature during sleep cycles, boredom, or stress. The average person yawns about 20 times a day. Yawning might be the brain's way of waking a person up, causing stimulation of the carotid artery and increasing heart rate.
References:
[1] Bradley, V. A., & Lade, S. L. (2000). Contagious yawning: An evolutionary perspective. Behavioral and Brain Sciences, 23(5), 681-734.
[2] Plate, R., & Hofmann, J. (2009). Yawning: Functions and mechanisms. Progress in Brain Research, 177, 193-207.
[3] Provine, R. R. (1986). Yawning: A social contagion. American Scientist, 74(6), 544-551.
[4] Berridge, K. C., & Berridge, C. W. (2009). The neuroscience of yawning and its control. Progress in Brain Research, 177, 177-191.
[5] Ford, D. C., & Plate, R. (2012). Yawning and its functions: New insights from basic and clinical research. Sleep Medicine Reviews, 16(4), 355-363.
- The theory of brain cooling or thermoregulation suggests that yawning may help optimize performance during thermal stress or before sleep by cooling the brain through deep inhalation.
- Yawning is linked to an increase in heart rate and stimulation of alertness, which may serve as a mechanism to keep the brain awake and ready, especially when drowsy or transitioning between sleep and wakefulness.
- Contagious yawning, a common phenomenon in social or pack animals, functions as a nonverbal communication signal to synchronize group behavior and express empathy or social bonding.
