What is the scientific reason as to why yawns are contageous?

Question

My friend and I are talking about yawning. We know that they are caused due to lack of oxygen to the brain, but we were wondering exactly why they are SO contageous! Does anyone know why we yawn when we so much as hear another person yawn? The more details the better. Thanks!

Answer 1

The yawn reflex is often described as contagious: if one person yawns, this will cause another person to "sympathetically" yawn. The proximate cause for contagious yawning may lie with mirror neurons, i.e. neurons in the frontal cortex of certain vertebrates, which upon being exposed to a stimulus from conspecific (same species) and occasionally interspecific organisms, activates the same regions in the brain. Mirror neurons have been proposed as a driving force for imitation which lies at the root of much human learning, e.g. language acquisition. Yawning may be an offshoot of the same imitative impulse.

At a distal level (in terms of evolutionary advantage), yawning might be a herd instinct. Other theories suggest that the yawn serves to synchronize mood behavior among gregarious animals, similar to the howling of the wolf pack. It signals tiredness to other members of the group in order to synchronize sleeping patterns and periods of activity. It can serve as a warning in displaying large, canine teeth. This phenomenon has been observed among various primates. The threat gesture is a way of maintaining order in the primates' social structure. The contagion of yawning is interspecific, for example a human yawning in front of a pet dog can incite the dog to yawn as well. A specific study was conducted on chimpanzees. A group of chimpanzees was shown a video of other chimpanzees yawning, and the study chimpanzees yawned also. This helps to partly confirm a yawn's "contagiousness".-

Answer 2

Actually Jerry S, you're wrong about the hot surface example...
on the skin you have sensor(feeling) neurons which will feel the heat, send an electric impulse(like a message) to the central nervous system(brain+spine) and, if it's a survival thing, something that requires fast action, like getting burned on a stove, the message only gets to the spine, which will quickly activate the motor(moving) neurons in your hand and stop you from burning.
it's called a reflex arc.

as to the original question, i don't really know why they are contagious, but i do know that it's supposed to be to "wake up" the muscles in your face, i didn't know the oxygent part of yawns.

Answer 3

The scientific reason is that there is a lack of oxygen in that area of the room. So your instincts tell you to gulp more air. When another person witnesses this, the survial part of their instincts kick in before their body is even deprived of oxygen, thus forcing them to yawn as well.

Answer 4

because we feel comfortable around people who yawn. when we get coomfotable we get a bit sleepy and yawn. Ever notice most people u run into don't yawn at once. maybe everyone is running away from the "sleeppy" yawners... :)

Answer 5

sorry, i dont know but i think its just a mental thing