Ever wondered about what causes tickling? What are the mechanisms that trigger the sensation over which we have little control, and, why do we laugh when we are tickled? Let us find out now!
What are knismesis and gargalesis?
Tickling exists in two types: knismesis and gargalesis.
These two broad categories were named by psychologists G. Stanley Hall and Arthur Allin in 1897. Basically, what differentiates between the two types is which one causes the person to laugh, almost as if inexplicably, one of them giving a light sensation, while the other is more of a “heavy tickle”.
Knismesis is the term used to describe the former type: the feathery-like tickling. This one does not cause the person to explode into laughter fits. It is more similar to itching sensations.
Gargalesis, however, entails heavy tickling which induces laughter. This one occurs as a consequence of applying high pressure onto those regions of the skin most sensitive to sensations of tickling.
What is Knismesis
This requires lighter touches to stimulate the tickle-sensations. For example, it can be triggered by the movement of light creatures onto the sensitive regions of the body, like crawling insects. These stimuluses might be acting to make the person get rid of the pest at the itching sensations. Many different animal species feel this kind of tickling, including white sharks, which can be dragged into a trance-like state if it is continually tickled.
This response can be triggered by oneself on oneself as well. Mild electricity has also been shown to produce that effect. It is generally a much calmer sensation as the second type of tickling, since it is the gentle-touch nerves that are activated, providing a relaxed feeling, explaining the trance caused to white sharks.
What is Gargalesis
This type of tickling is more common in humans and primates. Other species might be made subject to gargalesis as well. A different type of nerve cells is stimulated. Different types of touches are felt by different types of nerves. For instance, light touch is sensed by one kind of nerve, while heavier touches are experienced via another type. This might mean that the different sensations felt of both types of tickling is because of the level of itch sensation as compared to the touch sensation.
The response to gargalesis is mostly impossible to self-induce, because it involves applying heavier pressures onto the specific sensitive parts of the body. It is much more unpleasant that the former type; at least, in most cases.
Hypergargalesthesia entails extreme sensitivity to tickling.
Why does tickling trigger bouts of laughter?
Now, the questions that you must be asking yourself. If gargalesis is so unpleasant, why does it still make people break into laughter fits like nothing else? Then, why can’t it be self-induced if one triggers all those regions that are otherwise known to cause tickling sensations?
Researchers have come up with possible explanations to try to justify the existence of such responses as laughter to tickling. It goes as follows:
When one is being tickled such that laughter is almost impossible to stop, the person doing the tickling will most probably feel more inclined to continuing the tickling, as opposed to the instance where the person tickled would have less nice expressions on the face. As the tickling is thus continued, this action and reaction promotes the development of combat skills. It has previously been observed that some animals like chimps and the deer, and most young mammals enjoy themselves indulging on this kind of activity with the purpose to develop their skills to defend themselves. However, they do not laugh.
Scientists have not as yet found the reason behind the inability to self-induce this type of tickling. When we know where are the tickling regions of the body, why can’t we induce that feeling? Maybe, it can only be triggered when it happens without the prior knowledge of the person in question. Maybe, it has to do with the brain controlling the action, such that when we self-trigger it, it does not produce the same reaction as when someone else does it!
Yet, we have been endowed with these extremely particular sensitive areas that succumb to tickling – they specifically exist, and, they are real, we cannot deny these facts. Then, what is their purpose? What do they serve us for? Just adding up to the mysteries of life…