The Hidden Secrets Of Yawning

The precise reasons why we yawn have puzzled scientists since they first started thinking about this contagious, slow-motion, mouth-opening motion. And now there’s a new wrinkle in the conundrum. Researchers have discovered that fetuses yawn in the womb.

Using ultrasound video recordings, researchers have worked out a technique to distinguish prenatal yawns from simple mouth openings.

In the study, scientists scanned 15 healthy fetuses, eight girls and seven boys, at 24, 28, 32 and 36 weeks’ gestation. By timing the actions and analyzing the shapes of the fetuses’ mouths, the scientists were able to distinguish yawns from random jaw openings. In all, they counted 56 yawns and 27 non-yawn oral openings. They also discovered that the yawning stopped at 36 weeks.

Though the researchers believe that fetus and adult yawns occur for different reasons, it remains unclear what the reasons are in either case.

“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.”

Sam Rolley

By Sam Rolley

After covering news and politics for traditional media outlets, Sam Rolley took a position at Personal Liberty Media Group where he focuses on his true passions: national politics and liberty issues. In his daily columns and reports, Rolley works to help readers recognize lies perpetuated by the mainstream media and develop a better understanding of issues ignored by more conventional outlets. Follow him on Twitter @SamRolley