Under the feet, the neck and the armpits - these are places that many people find ticklish. It also seems to vary across cultures, according to new research. At least that is the case for people from Chinese, Greek and Dutch cultures, who participated in a study published in Nature Human Behaviour.
The results are based on responses from more than 450 adults who were asked questions about where on their bodies they find ticklish, among other things. Across all three cultural groups, participants consistently described the neck, armpits, stomach and soles of the feet as ticklish areas.
Why are we ticklish?
There are areas that seem universal, says Konstantina Kilteni, one of the study authors and a researcher at the Karolinska Institute and the Donders Institute for Brain, Cognition and Behaviour in the Netherlands, to TT.
Among other things, she is seeking answers to why we are ticklish.
Aristotle and even Darwin wondered about it and have presented theories, but we don't have a simple answer, she says.
One theory is that the most ticklish areas on the body are the ones most susceptible to injury. Other theories are that it is about areas that are not touched as often or that the skin is thinner there.
In this study, the researchers only saw a connection between ticklish areas and areas that are not frequently touched.
It is probably a complex mix of sensory, physiological and psychological factors.
Difficult to tickle yourself
Research also shows that the laughter that comes when we are tickled is special.
It has been seen that it differs sonically from laughter that comes when we laugh at a joke or something we see, says Konstantina Kilteni.
And one thing is for sure: it's almost impossible to tickle yourself.
We think this is because there is no surprise. When we tickle ourselves, the brain knows where and when it should happen and then it doesn't tickle, says Konstantina Kilteni.
However, some people with schizophrenia experience their own touch as more ticklish than healthy people, suggesting that there may be a difference in how the brain interprets sensory impressions from one's own body.
For anyone wondering why it is important to research ticklishness, Konstantina Kilteni has an answer.
Tickling may seem simple and fun, but it is scientifically relevant. Through research, we can learn more about evolution, developmental and clinical neuroscience, she says.
Researchers divide the feeling of tickling into two different types: knismesis, which is a light touch that can be triggered by, for example, an insect, and gargalesis, a more forceful touch that can cause laughter.
