Ultrasound Video Captures Fetuses Yawning … Why Do They Do It?
Yawning is a behavior that everyone is aware of, and we all take part in it, yet no one knows the precise reason why we do it. There’s a ton of theories: A need to rapidly get oxygen into the blood, a way to remain alert for possible danger, imbalances in neurotransmitter levels, and even regulating brain temperature. None of them have been completely proven right or wrong.
The social aspect of yawning is much better understood. It is likely a way for social animals to synchronize their mood and sleep schedules, as well as communicate empathy. Of course, a fetus can’t communicate with anyone (except via kicking), so why would they need to yawn?
New research (check out the paper in PLOS One) suggests that it could be part of brain maturation. As the fetal brain develops, the neural cycles that will later become sleep and wakefulness are kicking in. It could even be as simple as a way to exercise the jaw movements that will later be necessary in nursing and crying. Whatever the reason, we now have visual proof of certifiable yawns kicking in long before birth, and it’s kind of freaky looking. More research (in adults, children and prenatal infants) will be needed to get at the “why”.
By the way, if you yawned while reading this, you aren’t alone. About 60% of people reading or thinking about yawning will yawn.
(GIF adapted from video by Wolfgang Moroder)