Thursday, February 2

Why we can’t tickle ourselves

There is no doubt that laughing –and smiling– It is good for health, both physical and mental. and a way easy to provoke laughter is resorting to tickling. Tickling also seeks closeness and physical contact, especially with the little ones in the house. And there is no doubt that it leads to funny moments.

There are two types of tickling

At the end of the 19th century, it was described that we can perceive tickling in two different ways, which were called knismesis Y gargalesis. The knismesis They are soft and light tickles, like those generated by the rubbing of a feather. The sensation is rather itchy and does not usually cause laughter. The gargalesis It refers to the most intense tickles, which produce laughter when they are done in specific areas of the body.

There are studies which indicate that tickling generates one sensation or the other, but generally not both at the same time. It seems that because the sensitive receptors in the skin, and also the associated nerve pathways, are different.

The intense tickling

Gargalesis-type tickles, that is, those of laughter, are more complicated than knismesis-type caresses. The studies The studies carried out suggest that the laughter that appears with tickling is more the consequence of a social behavior than a reflex, for example in the interaction between mother and child, or in the sexual prelude.

Also, when intensely tickled, elements of dominance and submission come into play. And we must bear in mind that the laughter caused by tickling does not imply that we feel like laughing at that precise moment, since they also depend on the context and mood.

As indicated above, intense tickling only occurs if it is provoked in certain parts of the body, mainly the sole of the foot, the armpits, the neck and the chin. From a behavioral point of view, they have a place of their own as the only form of contact that makes people laugh. And we know well that we cannot cause them to ourselves. But why not?

If I do them I don’t laugh

Our body is responsible for collecting and processing sensory information through a complex system of receptors and nerve pathways called the somatosensory system.

When we cause ourselves a tactile sensation, the somatosensory system perceives it with less intensity than if the source of stimulation is external. Everything indicates that this is due to the difference in predictive capacity regarding the consequences that self-generated actions may have compared to external actions.

In other words, our brain interprets its own tactile stimulus as less threatening than an external one. And this also happens with tickling, both light and intense.

measuring the tickles

A couple of months ago a scientific study very interesting whose objective was to try to characterize the physiology of intense tickling (gargalesis) and its suppression by self-stimulation.

Eight girls and four boys participated, with an average age of about 30 years. They were grouped in pairs that belonged to the same social circle to ensure, let’s say, a certain familiarity and facilitate the study.

Each person sooner or later adopted the role of tickling or receiving tickling according to their own choice. The response to tickling was quantified from acoustic, visual and physiological measurements, and taking into account the subjective experience of each participant.

Physiological changes (in chest girth and facial expressions) were detected to appear simultaneously about 0.3 seconds after the stimulus, and vocalization about 0.2 seconds later. Both the duration time and the vocalization properties were correlated with the subjective experience: the more laughter, the greater the sensation of tickling.


When each person was asked to perform the tickling gesture while receiving it from their colleague, the sensation diminished and the vocalization was delayed. Especially if she was actually trying to tickle herself.

Everything points to the fact that, in general, when we touch ourselves, a inhibition mechanism and suppression of vocalization. And that is why if you tickle yourself at the same time that someone else is tickling you, the effect decreases, or that you don’t laugh at all if you only do them yourself.

This article was originally published on The Conversation.

you can read it here.



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