We tend to associate tickling with fun and intimacy. Neuroscientists know that the cause of these positive feelings is dopamine, when someone tickles us is released this neurotransmitter, which is the key to the reward system in the brain and plays an essential role in laughter.
It has even come to identify those we could call the “tickling neurons” found in the somatosensory cortex of the brain that are not only involved in tact, but also play an important role in our mood.
Tickling Types
In 1987, psychologists Arthur Allin and Stanley Hall described two different types of tickling:
– Knismesis. It is a type of tickling that manifests itself more like a feeling of itching and intense tingling that can also be unpleasant. It’s the kind of tickle that gives us the touch of a feather and does not make us laugh.
Apparently, this tickle is an ancestral feature that allows us to immediately react to a potential danger, such as a spider or any other bug that walks on our body, and stimulates us to scratch ourselves to eliminate this danger. In fact, a study at the University of Tübingen revealed that tickling also activates the hypothalamus, a primitive area of the brain that triggers the primitive desire to escape the danger.
– Gargalesis. This kind of tickling is produced by deep and repeated pressure on some sensitive areas of the body. It is the kind of tickling that causes a pleasant feeling and makes us laugh. It is thought that it can serve to foster socialization, thus it would make us feel more secure and connected with people in an outwardly hostile world.
In fact, did you know that excessive tickling sensitivity is called hypergargalesthesia and is considered a mild nervous disorder?
Why do we suffer tickling?
Clearly the tickle, especially gargalesis, has a strong emotional and social component, so it is hypothesized that is linked to gaming. In fact, many of the neurons that are triggered by tickling are the ones that come into operation when we play. From this point of view, tickling would be a brain trick to make the game and interaction with others something more rewarding.
Early tickling promotes parents’ bonding with the child, helping to create an early association of pleasure. Later, brothers often resort to tickling not only to create affective bonds, but also as an alternative to violence, to bother the other. In this case, tickling helps them develop their defensive skills by teaching them to protect the most vulnerable parts of the body. In fact, if we pay attention we realize that the positions we take when are tickling us are defensive.
However, the tickle has not only a social component, but it can also help us deal better with the problems of life. A study at the Tsukuba International Foundation for the Advancement of International Science has found that tickling allows us to pass through difficult situations by experiencing less fear and, above all, recover faster from this negative experience.
These neuroscientists have discovered that tickling acts as a kind of protective shield, so that when we are faced with situations that create fear, the level of adrenaline in the blood is lower and we can keep calm.
Why can’t we tickle ourselves?
The tickle triggers an extreme response in areas of the body that are not directly related to skin sensitivity. The most sensitive areas are foot plants and other areas of the body where the skin is more sensitive.
It is likely that is due to the fact that in tickling has also an influence the surprise factor, and this is one of the reasons why we can’t tickle ourselves because we know exactly which part of the body we will touch.
Researchers from University College London found that when one tries to tickle himself, the cerebellum inhibits the cingulate front bark, it’s like is telling that there’s no need to react laughing because it’s a self-generated stimulation.
It was also seen that tickling is also inhibited in times of strong stress and anxiety. This confirms Charles Darwin’s observations: “The mind must be in a pleasant state for tickling to make laugh.”
Tickling as a method of torture
At the level of the nervous system, tickling stimulates the nerve fibers associated with both the touch and the pain. So why tickle is effective as a social bond both people have to feel comfortable with the situation, otherwise the tickle will give an unpleasant feeling. In fact, in many cultures it is used as a method of torture.
It is said that during the Han Dynasty in China, the tickle was a punishment reserved for the nobility as it left no marks on the victim and they could recover quickly. Also in Japan was employed in the same way, it was called kusuguri-Zeme, which means “tickle without piety”.
In ancient Rome the feet of the person were soaked in a saline solution, so it was immobilized and made sure that a goat licked the solution. At first the person felt only a slight tingling, but later became very painful.
In fact, the abuse of tickling can cause very intense reactions at physiological levels ranging from vomiting to incontinence or loss of consciousness for lack of breath.
But when tickling is practiced in an atmosphere of intimacy in which people feel at ease, it is an excellent technique to activate the emotional connection mechanism we have inside and is reserved only for the most intimate relationships.
Sources:
Hori, M. et. Al. (2013) Effects of repeated tickling on conditioned fear and hormonal responses in socially isolated rats. Neurosci Lett; 536: 85-89.
Wildgruber, D. et. Al. (2013) Different Types of Laughter Modulate Connectivity within Distinct Parts of the Laughter Perception Network. PLoS One;8(5):e63441.
Yamey, G. et. Al. (2001) Torture: European Instruments of Torture and Capital Punishment from the Middle Ages to Present. BMJ; 323(7308): 346.
Blakemore, S. J. et. Al. (2000) Why can’t you tickle yourself? Neuroreport; 11(11): 11-16.
