Yawning – that mysterious, contagious, and sometimes inappropriate action that we all do. It’s so common that scientists have been researching this simple act to better understand the reasons why it occurs. And recently, they discovered that even fetuses yawn in the womb!
Ultrasound Revelations
Using ultrasound video recordings, researchers have developed a technique to distinguish prenatal yawns from just opening the mouth. In the study, they scanned 15 healthy fetuses at 24, 28, 32, and 36 weeks’ gestation. By observing the timing and mouth shapes, they were able to differentiate yawns from random jaw openings, counting 56 yawns and 27 non-yawn oral openings. Interestingly, they found that the yawning stopped at 36 weeks.
While it is believed that fetuses and adults yawn for different reasons, the specific reasons are still unclear.
“When you see a fetus yawning, it’s not because it’s tired,” says the study’s lead author, Nadja Reissland, a developmental psychologist at Durham University in England. “The yawning itself might have some kind of function in healthy development. Fetuses yawn, and then as they develop they stop yawning. There’s something special in yawning.”
The Theories Behind Yawning
While the exact reasons behind yawning aren’t fully grasped, numerous theories have been proposed. Let’s dive into some of the most popular ones.
Regulating Brain Temperature
One fascinating theory suggests that yawning helps regulate brain temperature. This idea began with a study that found people yawned more often when their brains were warmer, so it was assumed that the act of yawning cooled them down. Yawning increases blood flow to the brain, and the deep inhalation of cool air is believed to help reduce brain temperature.
Keeping Us Alert
Another possibility is that yawning helps increase alertness. According to an article published in the journal Behavioural Brain Research, yawning could be a natural way of keeping us awake and focused when we’re feeling drowsy. The deep breath of a yawn may increase oxygen levels in the blood, providing the brain with a burst of energy.
Signaling Boredom or Empathy
Yawning could also be a social signal, indicating that we’re bored or empathizing with someone else who’s yawning. In a study with primates, researchers found that yawns were contagious and were used as a method of interaction between individuals. It’s believed that this may be true in humans as well, with yawning acting as a way to communicate non-verbally.
Stimulation of Brain Activity
Another theory proposes that yawning helps stimulate brain function. During periods of inactivity or fatigue, the brain’s levels of dopamine and serotonin can drop. These neurotransmitters are vital for maintaining alertness and controlling mood. Yawning might trigger the release of these essential chemicals, thereby helping to increase focus and concentration.
The Mystery Continues
Though researchers continue to uncover new details about yawning, the definitive answer to why we yawn remains a mystery. What seems clear is that yawning isn’t merely a sign of being tired or bored – it may have critical functions in our overall well-being. So, the next time you catch yourself yawning, remember that it’s your body’s natural way of keeping you healthy, alert, and functioning at your best!
