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Scientific study: duration of yawning as a sign of intelligence


Larger brains yawn longer
US researchers have found that the length of yawning is related to the size of the brain: the bigger the brain, the longer it yawns. The scientists assume that temperature regulation plays an important role here.

Yawning is contagious
When people yawn, it is usually a sign of tiredness or boredom. If you start with it, this also affects your counterpart: yawning is almost always contagious. Even some animals can be affected. Researchers found that human yawning is contagious in chimpanzees. Why we yawn is still not clearly understood. American scientists have now come one step closer to the answer.

Larger brains yawn longer
Researchers from the University of Vienna and the State University of New York (SUNY) reported years ago that yawning cools the brain. Yawning should provide a short stimulus for tired brains by stimulating blood flow in the skull, which in turn cools the neurons.

Now a team of scientists led by Andrew Gallup from SUNY has found that the length of the yawning is related to the size of the brain. Accordingly, the bigger the organ of thought is, the longer it yawns.

Researchers evaluated videos
For the study, which was published in the journal "Biology Letters", the researchers used videos from a total of 24 different animal species. They found that animals with fewer neurons and smaller brains yawn significantly shorter on average than those with large brains. According to the experts, the size of the animals or the number of bones moved when yawning played almost no role.

People yawn much longer
Humans have an average yawn time of around six and a half seconds and have 21 billion nerve cells. African elephants yawn the second longest with an average of just over six seconds and have the second most nerve cells. This is followed by two species of monkey with chimpanzees and gorillas in both categories. All of these animals are considered very intelligent.

Mice, on the other hand, only yawn for 0.8 seconds on average and “only” have four million nerve cells in the cerebrum.

Further investigation planned
"Whether yawning should specifically cool the brain can still be discussed, but there is no debate that yawning has thermoregulatory consequences," Gallup said according to "STAT". The researchers have already planned follow-up studies. They also want to test their thesis on fish, birds and other mammals and also investigate how the strikingly large differences in the yaw time in humans can be explained. In addition to brain cooling, social factors could also play a larger role here. (ad)

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