The dictionary of human interactions contains different forms and types of the concept of contact. There is touch, pressure, pinching, and another type of contact that usually provokes a feeling of laughter, which is tickling.
From the moment a person is born until they reach old age, you will find that a few touches with the fingers in the abdomen area, for example, make the person shudder, flex, laugh and may even scream with joy. Here the question comes to mind: What makes us laugh involuntarily when we are tickled?
“The feeling of being tickled is a very unique response, and it falls within the framework of self-sensitivity to external stimuli,” says researcher Sandra Broels of the Bernstein Center for Computational Neuroscience in the German capital.
Although this issue is still shrouded in great mystery, scientists like Broyles have come up with interesting explanations and answers about the nature of this response, and what happens to us when we are exposed to this external stimulus.
When discussing the concept of tickling, scientists emphasize the need to distinguish between two different feelings. The first is the feeling resulting from light contact with the skin with a soft object such as a feather or hair, known as knismesis, and usually does not provoke a desire to laugh, but usually leaves an itchy sensation on the skin. The second feeling is called gargalesis, and is caused by repeated pressure on a specific area of the body, which provokes a desire to laugh.
Protect the body from parasites
“They are two completely different things,” says researcher Shimpei Ishiyama, a neuroscientist at the Institute of Mental Health in Mannheim, Germany. “The purpose of the first is to reduce the possibility of skin injury due to external friction,” he told the website Popular Science, which specializes in scientific research. “The purpose of this response is to protect the body from parasites,” such as cows that constantly swish their tails to ward off flies.
He added that as for heavy tickling, there are many theories that explain it and clarify its causes, including that its purpose is the automatic defense of weak parts or sensitive centers in the body. Showing a strong response, even if it is in a playful manner, may prevent what is supposed to be an external attack threatening the human body, although he believes that this theory is not comprehensive in light of the fact that touching some parts of the body provokes a feeling of tickling even though they are not considered weak or sensitive areas such as the soles of the feet, for example.
Ishiyama believes that the feeling of being tickled is part of the act of petting and strengthening social bonds between members of the same species, and it also has some secondary benefits. It is not limited to humans, as some species of great apes and rodents have been shown to show a similar response to being tickled.
He noted that the common element in all ticklish creatures is that they are all “social mammals that play together, roughhouse with each other and communicate with each other.”
One of the points that supports the previous theory is that tickling is ultimately a conscious process linked to the social context. Humans and animals feel tickled when they are in a positive emotional state and a mood that tends to want to play.
mixed feelings
“The response to tickling is related to familiarity between people,” Broyles told Popular Science. “Tickling won’t elicit laughter when you’re with strangers. Anxiety can reduce the sensation of tickling, and you can’t elicit laughter when you’re tickling yourself. So tickling is a response that has to happen in a social context.”
Scientists have examined the parts of the brain that are particularly affected by tickling, and experiments conducted on mice have shown that the parts of the brain that are affected during play are the same as those affected when feeling tickled, in addition to the areas within the brain associated with the feeling of touch or the violent response in cases of flight, fight, or vocalization, and some parts related to emotional feelings such as the amygdala and the anterior cingulate cortex.
Scientists have looked at the conflicting emotions that accompany tickling, and wondered whether tickling is always a source of joy and happiness.
Tests on rats have shown that tickling can sometimes be used as part of a reward system during training, Broyles says, and a study by Ishiyama earlier this year showed that it can also be a sensory stimulant. But both humans and rats show fear when they are in a situation where they might be tickled, and sometimes they show aversion to tickling and then come for more at the same time, Ishiyama says.
Some historical accounts indicate that tickling was used in the past as a means of torture, especially when it was outside the framework of foreplay and intimacy and was done in an unwanted manner. In this case, the victim would feel disturbed and uncomfortable, and the tickling would not arouse any desire or feeling of laughter in him.