Yawning+And+Why+They+Are+Contagious

the info she found in it was Yawning...And Why Yawns Are Contagious Everyone yawns - babies, kids, teenagers, adults. Some birds, reptiles and most mammals also yawn. However, the reason why we yawn is a bit of a mystery. There is also very little research about yawning because for most people yawning is not a problem. Here are a few things that are known about yawns: You know that when you are bored, you yawn. Scientists have confirmed this observation by comparing the number of yawns in 17-19 year old students who watched music videos to the number of yawns in students who watched an uninteresting color test bar pattern. Many people assume that we yawn because our bodies are trying to get rid of extra carbon dioxide and to take in more oxygen. This may make some sense. According to this theory, when people are bored or tired, they breathe more slowly. As breathing slows down, less oxygen makes it to the lungs. As carbon dioxide builds up in the blood, a message to the brain results in signals back to the lungs saying, "Take a deep breath," and a yawn is produced. The only problem with the excess carbon dioxide theory is that research shows that it may not be true. In 1987, Dr. Robert Provine and his coworkers set up an experiment to test the theory that high carbon dioxide/low oxygen blood content causes yawning. Air is normally made up of 20.95% oxygen, 79.02% nitrogen), 0.03% carbon dioxide and a few other gases in low concentrations. So, the question remains - why do we yawn? Some people suggests that perhaps yawning is like stretching. Yawning and stretching increase blood pressure and heart rate and also flex muscles and joints. Evidence that yawning and stretching may be related comes from the observation that if you try to stifle or prevent a yawn by clenching your jaws shut, the yawn is somewhat "unsatisfying." For some reason, the stretching of jaw and face muscles is necessary for a good yawn. It is possible that yawns are contagious because at one time in evolutionary history, the yawn served to coordinate the social behavior of a group of animals. When one member of the group yawned to signal an event, all the other members of the group also yawned. Yawns may still be contagious these days because of a leftover response (a "vestigial" response) that is not used anymore. None of this has been proven true and yawns are still one of the mysteries of the mind. When she finished, the plane had stopped and she hopped out to see the BUSH FIRES!!!!
 * 1) The average duration of a yawn is about 6 seconds.
 * 2) In humans, the earliest occurrence of a yawn happens at about 11 weeks after conception - that's BEFORE the baby is born!
 * 3) Yawns become contagious to people between the first and second years of life.