We've all been tickled at some point or another, but we haven't all enjoyed it — in fact, some people really don't like it. Actually, when you really think about it... does anybody appreciate being tickled? Sure, babies tend to dissolve into a fit of giggles when you poke and prod at certain spots (like under the arms and feet), and most small children seem to find the experience similarly hilarious. But just because little ones laugh when they're being tickled doesn't mean they think it's funny. So why do we grow up hating to be tickled? (And why do we laugh through our misery?!)
The answer is a complicated one, and the subject of a surprising amount of scientific (and sometimes conflicting) research. For example, while some studies have shown laughter when being tickled to be a physical reflex (kind of like what happens when a doctor taps on your knee with a rubber hammer, other experts — such as Dr. Alan Fridlund, a tickle researcher who is a psychologist at the University of California at Santa Barbara — maintain that ticklish laughter is social, depending on a tension created between two or more people (as with a joke), noted The New York Times. Yet another possibility is that our response to being tickled is a combination of nature and nurture.
"Tickling involves the neurological program for the generation of self and other," University of Maryland neuroscientist Robert Provine, author of Curious Behavior: Yawning, Laughing, Hiccupping, and Beyond, told The Washington Post. In layperson's terms, this means that the way our brains respond to being tickled is a way to distinguish between touching and being touched (this would explain why you can't tickle yourself). Or, going back to more primitive times, tickling's evolutionary roots might have been considerably darker: The Daily Mail reported that scientists at Germany's University of Tuebingen discovered that tickling activates the part of our brain that anticipates pain, and theorized that because our most ticklish parts are generally the weakest, too (think the neck and stomach), early human parents might have tickled their children to teach them how to react to a threat... with laughter serving as "an acknowledgement of defeat."
"When you tickle someone, you actually stimulate the unmyelinated nerve fibers that cause pain," said Dr. Alan Hirsch, founder of the Smell & Taste Treatment and Research Foundation in Chicago told The Daily Mail. Fascinatingly, rats and apes also "laugh" when tickled, according to Mental Floss.
Of course, the way we use tickling in modern day life has evolved beyond these biological functions: Among the reasons why the subjects Provine studied gave for engaging in tickling were "showing affection and getting attention," even though nobody seems to love it — Provine's studies also showed that people rate being tickled at a 5 on a 10-point scale (from very unpleasant to very pleasant). Interestingly, nobody seems to love tickling other people either, as that activity was rated at only at 5.9 on average.
And yet, tickling remains a thing we do as humans, generation after generation. In fact, it's even become something of a competitive endurance sport, as the documentary "Tickled" proves. Again, the term "endurance" implies that tickling is something to be endured... as in, something nobody really likes, whether or not they're laughing about it. Considering our bodies and minds are potentially hardwired to associate tickling with pain and mortal danger, it makes sense that most of us assume a defensive pose when someone starts mischievously wiggling their fingers at us. This is especially true for anyone who grew up with an older sibling (or cousin, etc.) who used tickling as a method of torment. (Fact: Tickling was employed as a legit form of torture in China during the Han dynasty for nobility because it didn't leave marks, like other forms of torture).
I have one friend who still shudders visibly at the mention of "tickle planes," something an otherwise perfectly nice relative of hers used to think was a hilarious way to tease her as a kid. Our parents or older brothers and sisters might not have meant to traumatize us when they pinned us down for a game of "tickle monster," but that doesn't mean those experiences didn't scar us for life to some degree.
Basically, it all boils down to this: You have every reason to hate being tickled. (And also: If your kid protests about being tickled, don't force it!)
Check out Romper's new video series, Bearing The Motherload, where disagreeing parents from different sides of an issue sit down with a mediator and talk about how to support (and not judge) each other’s parenting perspectives. New episodes air Mondays on Facebook.