Yawn is defined as an involuntary process to open the mouth widely, take a deep breath and then release which could be the sign of boredom or lethargies. As mentioned, it is an involuntary process but human beings have got an ability to control it due to cultural and societal reasons. Yawning is a psychological phenomenon due to which a person also yawns if he looks at someone yawning or reads about it. This is the reason why yawning is considered as contagious (Buttner & Strasser, 2014).
There are different types of yawns which are observed by the scientists. The first one is universal yawning which is observed in all i.e. in human beings as well as animals. This type of yawn is connected with sleep, hunger or other such stimuli. These are said to be produced by the emotionless part of the brain. It is the most common type of yawn. The second category of yawn is of emotional yawning. This category of yawning is observed in mammals and can help them to get calm after anxiety or stress. These are produced by paleomammalian brain. In human beings this kind of yawning brings in an anti- stress effect. This is the reason why mostly athletes yawn before going for the sport (Gallup, 2011). The third category of yawning is contagious yawning. This yawn is caused by looking at someone who is already yawning. This shows a special feature of brain. Many scientists relate contagious with empathy. If functional imaging of the brain is done at this time it is seen that the same brain functions activate at the time of contagious yawning as that activated when an emotion of empathy is felt by the brain.
However, yawning is mostly linked with boredom and dullness. It is a common understanding that if a human being is bored or is sitting idle for a long time he or she tends to yawn.