Why do we yawn? Why is it contiguous i.e., if one person in the meeting yawns all other starts yawning?

Answer 1

Yawning is an involuntary action that causes us to open our mouths wide and breathe in deeply. We know it's involuntary because we do it even before we are born. Research shows that 11-week-old fetuses yawn.

There are many parts of the body that are in action when you yawn. First, your mouth opens and jaw drops, allowing as much air to be taken in as possible. When you inhale, the air taken in is filling your lungs. Your abdominal muscles flex and your diaphragm is pushed down. The air you breath in expands the lungs to capacity and then some of the air is blown back out.

While the dictionary tells us that yawning is caused by being fatigued, drowsy or bored, scientists are discovering that there is more to yawning than what most people think. Not much is known about why we yawn or if it serves any useful function, and very little research has been done on the subject. However, there are several theories about why we yawn. Here are the three most common theories:

The Physiological Theory -- Our bodies induce yawning to drawn in more oxygen or remove a build-up of carbon dioxide. This theory helps explain why we yawn in groups. Larger groups produce more carbon dioxide, which means our bodies would act to draw in more oxygen and get rid of the excess carbon dioxide. However, if our bodies make us yawn to drawn in needed oxygen, wouldn't we yawn during exercise? Robert Provine, a psychologist at the University of Maryland, Baltimore County, and a leading expert on yawning, has tested this theory. Giving people additional oxygen didn't decrease yawning and decreasing the amount of carbon dioxide in a subject's environment also didn't prevent yawning.

The Evolution Theory -- Some think that yawning is something that began with our ancestors, who used yawning to show their teeth and intimidate others. An offshoot of this theory is the idea that yawning developed from early man as a signal for us to change activities.

The Boredom Theory -- In the dictionary, yawning is said to be caused by boredom, fatigue or drowsiness. Although we do tend to yawn when bored or tired, this theory doesn't explain why Olympic athletes yawn right before they compete in their event. It's doubtful that they are bored with the world watching them.

The simple truth is that even though humans have been yawning for possibly as long as they have existed, we have no clue as to why we do it. Maybe it serves some healthful purpose. It does cause us to draw in more air and our hearts to race faster than normal, but so does exercise. There's still much we don't understand about our own brains, so maybe yawning is triggered by some area of the brain we have yet to discover. We do know that yawning is not limited to man. Cats, dogs, even fish yawn, which leads us back to the idea that yawning is some form of communication.

It may not be one of life’s deepest mysteries, but as scientific conundrums go, it has a peculiar staying power. Researchers recently found that yawning isn’t only catching among people; it is also among chimpanzees

Compounding the mystery is the odd way in which the contagious power of yawning is largely unconscious. We can see someone yawn, yearn to replicate the action ourselves, and do it, all without thinking about it. Other times we’re aware it is happening, though it still floats somewhere beneath the realm of reason and of purposeful actions.

So what gives? In an effort to find the answer, the Finnish government recently funded a brain scanning study. The results turned up some hard-to-interpret, possible clues. It also confirmed the obvious: yawn contagion is largely unconscious. Wherever it might affect the brain, it bypasses the known brain circuitry for consciously analyzing and mimicking other people’s actions.

This circuitry is called the “mirror-neuron system,” because it contains a special type of brain cells, or neurons, that become active both when their owner does something, and when he or she senses someone else doing the same thing.

Mirror neurons typically become active when a person consciously imitates an action of someone else, a process associated with learning. But they seem to play no role in yawn contagiousness, the researchers in the new study found. The cells are have no extra activity during contagious yawning compared with during other non-contagious facial movements, they observed.

Brain activity associated with viewing another person yawn seems to circumvent the essential parts of the MNS [mirror neuron system], in line with the nature of contagious yawns as automatically released behavioural acts—rather than truly imitated motor patterns that would require detailed action understanding,

But if seeing someone yawn doesn’t activate these centers, what does it do to the brain? The researchers found that it appears to strongly activate at least one brain area, called the superior temporal sulcus. But this activation was unrelated to any desire to yawn in response, so it may be irrelevant to the contagion question, the researchers added.

Possibly more significant, they wrote, was the apparent deactivation of a second brain area, called the left periamygdalar region. The more strongly a participant reported wanting to yawn in response to another person’s yawn, the stronger was this deactivation. “This finding represents the first known neurophysiological signature of perceived yawn contagiousness,” the researchers wrote.

Exactly what the finding means is less clear, they acknowledged. The periamygdalar region is a zone that lies alongside the amygdala, an almond-shaped structure deep in the brain in the area of the side of the head. The periamygdalar region has been linked to the unconscious analysis of emotional expressions in faces. Why it would be deactivated in tandem with yawn contagion is unclear, the researchers said.

One thing seems clear from the study is that “contagious yawning does not rely on brain mechanisms of action understanding,”. Rather, it seems to be an “‘automatically’ released (and most likely very archaic) motor pattern,” or sequence of physical actions.

In the study, volunteers looked at videos of actors yawning or making other mouth movements. Meanwhile their brains were scanned using functional Magnetic Resonance Imaging, a system that shows the amount of activity or work going on in various brain areas based on the amount of oxygen being used up there. The volunteers were later asked how strongly they had been tempted to yawn while viewing the pictures.

Apart from the physical brain mechanisms of yawn contagiousness, researchers have offered different reasons as to why it exists. Some have proposed that in early humans, yawn contagiousness might have helped people communicate their alertness levels to each other, and thus coordinate their sleep schedules.

This might be part of a more general phenomenon of unconscious signals that serve to synchronize group behavior. “Such synchronization could be essential for species survival and works without action understanding, like when a flock of birds rises to the air as soon as the first bird does so—supposably as it notices a predator.”

Answer 2

The word is contagious, meaning it is spread from organism to organism. If we observe the behaviour of other primates, we learn that yawning is often a signal of nervousness, which is a knee-jerk display of our teeth, our first line of defense. So we are warning other people. Now as we become sleepy, we become vulnerable, so we are warning other primates to not take advantage of us, that our teeth are intact and ready for defense. Now, if one person yawns, then other people become threatened and want to show off their own first-line of defense, their own teeth.

I first observed this on the Art Linkletter show maybe 40 yrs ago, when Art yawned and then they showed that many people in the audience yawned also. So this behaviour is well known by pyschologists and biologists.

Answer 3

Yawning is an extra deep breath; it is thought to flush out the "old" air that stays behind in the alveoli when we breathe normally.

Why it is connected to tiredness and how it is affected by social psychology is a different story...

Answer 4

if a individual all of the sudden appears at his correct/left part like some thing occurred u additionally verify out correct, it is human nature,, hmmm and while ur mind sees anybody is yawning it signals ur lazy bone and encourage u to yawn too and now

Answer 5

we yawn cos our lungs need more oxygen and yeah, it's kinda contiguous huh?

Answer 6

therefore, if you're in school, your teacher's boring... if you're in the office, your boss is stupid,,,

if you're at home, your life's boring...

Answer 7

yes it is contagious dunno why but it is