Baby Talk: Ever wondered whether yawns are contagious? Here’s your answer

Yawning.

Simply looking at the word can stimulate a yawn. I’m actually yawning while typing this piece.

Interestingly, all vertebrates — a living being with a spinal column — yawn. Vertebrates include mammals, birds, reptiles, amphibians and fish. Have to admit it is hard to imagine a fish yawning, but they do.

Not all vertebrates are subject to contagious yawning, like I just did when I typed the word. Humans, chimpanzees and the family of wolves and dogs are known to experience contagious yawning.

The human fetus growing inside the mother yawns. It is not because it is bored or sleepy. It is believed it is an essential process linked to brain development.

Researchers at Durham University in England, using high resolution ultrasound, have confirmed that human babies yawn as they grow inside their mother. They define a proper yawn — love how the English used the word proper — as “the slow opening of the mouth to its full stretch, followed by more rapid closure.”

Interestingly, as part of their research, they found the fetus yawns most frequently in the first 28 weeks of the pregnancy. They believe this yawning is linked to maturing of the brain early in gestation.

These same researchers found that as a baby nears completion of the 36th week of the pregnancy, yawning dramatically declines.

Why do we yawn? Yawning is defined as “an involuntary wide opening of the mouth with maximal widening of the jaw, together with a long and deep inhalation through the mouth and nose, followed by a slow expiration, associated with a feeling of comfort.”

The average time is takes to yawn is 6 seconds.

We yawn when we are sleepy, bored, nervous or we see or hear another yawn. Maybe even when we read about yawning.

It is speculated we yawn when we are sleepy or bored to help arouse the brain to stay awake. The gaping of the mouth and deep inhalation of cool air during a yawn alters the temperature of blood going from the lungs to the brain.

A friend of mine who works for the sheriff’s office has told me that during an interrogation, the officer will be looking for yawns. The more nervous and possibly guilty a person is, the more they will yawn.

The more empathetic our personality, the more likely we will experience contagious yawning.

Empathy, the ability to understand and share the feelings of others, is developed as we grow and understand the needs of other people. Toddlers rarely contagiously yawn. Contagious yawning has been observed to start after a child is 4 or 5 years old.

Children younger than 4 do not have the neural mechanisms in their brains required to understand the needs of others. Toddlers can only relate to their own reality. Tantrums are a result of not understanding why someone else doesn’t give you what you want.

Hence toddlers are known to have tantrums. Their brains are not wired to understanding the world does not revolve around their wants.

Yawning, seemingly such a simple act, is quite complicated. The vagus nerve, which is the nerve connecting the throat and abdomen to the brain, can cause excessive yawning by interacting with the blood vessels.

This may be a sign of a sleep disorder or brain condition. It can even be a sign of heart conditions, such as a heart attack or problems with the aorta. Anyone experiencing excessive yawning should see a medical professional.

All of that said, if you are yawning after reading this, I hope it wasn’t because you were bored.

Katie Powers, R.N., is a board-certified lactation consultant and perinatal educator at Manatee Memorial Hospital’s Family BirthPlace. Her column appears every other week in Healthy Living in the Bradenton Herald. Contact her at katie.powers@mmhhs.com.