Laughter is generally associated with pleasure and humour. But it can also happen uncontrollably when we are tickled and, until the tickling actions stops, it is virtually i,possible to control the laughing fit. However, it cannot be said that this exhibition of laughter is associated with humour, in that it is not caused by something we might find funny, such as a joke or an amusing incident we see. Neither is it necessarily pleasurable. In fact sometimes it can be quite painful. So why do we laugh when we are tickled, although when we try to tickle ourselves it does not cause the same reaction?
Most experts admit that as yet there is no consensus of opinion as to how laughter originates. What is known is that, unlike other emotions and actions, the act of laughing affects all areas of the brain. However, the reasons for laughter are varied, and it is in this variation that we might find the answer to the question "why do we laugh when we are ticked?"
Professor Robert Provine, Ph.D., a psychologist and neuroscientist from Baltimore, believes that laughter is an integral part of our communication process and signifies various emotional reactions. One of these applies to relationship, where laughter acts as a method of bonding people together. This is why people are attracted to others who make them laugh. Another is where laughter is used as a form of power, for example when a boss laughs their workers feel obligated to join in, thus accepting their boss's power ascendancy.
However, to understand the laughter from tickling, we have to look at two other areas of emotional response, which are play and reaction to events. The reason why children tend to laugh more than adults is because they spend a lot more of their time playing, and laughter is an involuntary response to the surprise that is an integral part of that play and a release of tension. Take hide and seek for example. The seeker will have the tension of looking for those who have hidden, not knowing what will happen when he or she looks in a particular place, and the surprise comes for both of these children when the one hiding is found. Thus laughter ensues as it expresses a release from the tension and a reaction to the surprise.
It is the same with tickling. The surprise and tension happens when the tickler initially strikes and the laughter is an relief and reaction to that process. The reason we do not stop after the initial touch is because we do not know what is going to happen next, so the brain is tensed in anticipation of the tockler's next movement. The reason we do not laugh when we tickle ourselves is because the brain is already aware of what is going to happen and where, thus there is no surprise and no need for tension.
Thus laughter when being tickled is a reaction to tension and surprise, not an expression of humour.