April 1 is of course the day of laughter. Jokes and pranks make us laugh, but even when we are tickled, most people cannot control their laughter.
Social psychologist Roza Kamiloglu from the Vrije Universiteit explains: “Tickle laughter is an automatic response: it happens before your brain can even think about what is happening.” The body takes over, as it were, completely independent of conscious control.
Tickle laughter is very different from laughing at a joke. While with humor you first have to understand something before you laugh, with tickling your body reacts automatically. Research by Kamiloglu and her colleagues, published in Royal Society’s Biology Lettersshows that this type of laughter not only sounds louder and more energetic, but is also so characteristic that people can recognize it just by listening, without knowing the context.
Tickling laughter is probably millions of years old. Kamiloglu says: “Chimpanzees, bonobos and even rats produce laugh-like sounds during playful tickling. So it is not a human invention, but a deep-seated social response.”
This type of laughter may have originated with the last common ancestor of the great apes, about ten million years ago, and served to strengthen playful contact and social bonds. The laughter, as it were, says: ‘This is fun, keep it up!’.
Not everyone reacts equally strongly to tickling. Predictability plays a major role: if you know where and when the tickle will come, it will feel less intense and that is why you cannot tickle yourself.
In addition, mood and context influence the response. Research on rats, which are also ticklish, shows that they react less when they are anxious. Finally, the sensitivity of the skin and nervous system varies from person to person, similar to how some people are more sensitive to cold or heat.
Kamiloglu emphasizes the difference: “Laughing at humor requires you to understand something. A joke, an absurdity or irony before you react. With tickle laughter everything happens automatically, without your brain making a choice.”
The result is uncontrolled, more energetic laughter, which is acoustically distinctly different from laughing at a joke or funny video. “Our analyzes with machine learning showed that tickle laughter has a different rhythm and more variable vocal outbursts, making it uniquely recognizable,” she explains.
Tickling is not only a funny experience, it also has a social function. “It is one of the oldest forms of play between people close to each other,” says Kamiloglu. In babies, laughing back when tickled helps build a bond with caregivers.
Because you can’t tickle yourself, it always requires another person, making it an eminently social experience. Kamiloglu emphasizes, “Tickle laughter strengthens relationships and creates safe, enjoyable interactions between people.”
That was a laugh, right? Do you also have a question that you really want to know the answer to? Or something you’ve always been curious about, but never dared to ask anyone? Send your question [email protected] and we may look into it for you soon.
