Gender differences in smiling behaviour

To beginn with, it is interesting to define what a smile is. On the Wikipedia webside we find the following, very comprehensive explanation that “in physiology, a smile is a facial expression formed by flexing muscles most notably near both ends of the mouth, but also around the eyes. Among humans, it is customarily an expression of pleasure or amusement, but can also be an involuntary expression of anxiety. There is much evidence that smiling is a normal reaction to certain stimuli and occurs regardless of culture. Happiness most often causes the smile to occur, though. Many studies indicate that smiling is an innate reaction, as children blind from birth, and even human fetuses smile; however feral children generally do not smile, perhaps lending evidence to the contrary. Among animals, the exposure of teeth, which may bear a resemblance to a smile, are often used as a threat - known as a snarl - or a sign of submission. Smiling not only changes a facial expression, but can also make the brain produce endorphins which reduces physical and emotional pain, and give a greater sense of well-being. “

This citation serves to get an impression on the complexity of the topic. It combines many different aspects and looks from many scientistic directions at the topic. Some of these we will get to know more deeply in the following.

Another definition of smiling is given by the researcher Guillaume Duchenne, who formed the theory of the “Duchenne smile”. It is the most studied, and involves the movement of both the zygomaticus major muscle near the mouth and the orbicularis oculi muscle near the eyes. An example of the smile is shown in the following fotograph:

http://en.wikipedia.org/wiki/Image:Iraqi_girl_smiles.jpg

It is believed that the Duchenne smile is only produced as an involuntary response to genuine emotion, and is therefore what we could call the “genuine” smile. However, some sources say that pretending to smile can eventually put you in a good mood, and therefore a fake smile can lead to a real one.