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Go on. Try it right now.
Take one finger and run it slowly along the bottom of your foot, or up the side of your ribs. Do it the exact way someone else would. Same speed. Same spot. Same light touch.
Nothing, right? Maybe a little itch. But not that helpless, can’t-breathe, stop-it-please feeling you get when someone else does it.
So why can’t you tickle yourself? The short answer is that your brain saw it coming. Every time you move, your brain makes a quiet guess about what that move will feel like, and then it turns the feeling down before it reaches you. You can’t surprise yourself, so you can’t tickle yourself.
But the long answer is much more fun. Scientists have poked at this question with feathers, fMRI scanners, and a pair of robots. And one of the things they found is so strange it almost sounds made up.
Why Can’t You Tickle Yourself? The Brain’s Quiet Prediction
Scientists have known for a long time that self-tickling doesn’t work. In 1971, a team led by the psychologist Lawrence Weiskrantz published a small study in the journal Nature. They brushed a stimulus across the soles of people’s feet. Sometimes the researcher did it. Sometimes the person did it to themselves. People rated their own touch as less tickly.
The question was why. The skin is the same skin. The feather is the same feather. So the difference has to be happening somewhere between the skin and the part of you that feels things.
In 1998, three researchers at University College London, Sarah-Jayne Blakemore, Daniel Wolpert and Chris Frith, put people inside a brain scanner and tickled their palms. Sometimes a machine did the tickling. Sometimes the person moved the machine themselves. Their study found that the part of the brain that handles touch lit up more when the tickle came from outside.
They also found something going on in the cerebellum. That is the wrinkly part at the back and bottom of your brain that helps you move smoothly. Their idea was simple. When you decide to move, your brain sends a copy of the order to itself. It says, in effect, “Here comes a touch on the palm, right about now, right about here.” Then it uses that guess to cancel out the feeling when it arrives.
Think of it like a friend who always tells you the end of the joke before the joke. By the time the punchline comes, there’s nothing left to laugh at.
The Robot Test: A Fifth of a Second Changes Everything
Here is the part most quick explanations skip, and it’s the best part.
In a follow-up study published in 1999, the same UCL team built a clever setup with two robots. A person moved a robot arm with their left hand. That movement drove a second robot, which brushed a soft piece of foam across their right palm. So the person was still tickling themselves, just through a machine.
Then the scientists started messing with the timing. They added tiny delays between the person’s move and the touch: a tenth of a second, two tenths, three tenths.
With no delay, the touch felt dull, as you’d expect. But as the delay grew, the tickle came back. At two tenths of a second, about a fifth of a second, people rated their own self-made touch as tickly as a touch made entirely by someone else. There was no real difference any more.
And here is the strange bit. Of the 16 people in the study, 14 said afterwards that they never noticed any delay at all.
Let that sink in. Their brains picked up a gap too small for most of them to consciously notice. And that gap was enough to switch the tickle back on. The researchers found the same thing when they twisted the direction of the touch a little, so it moved at an angle to the hand’s movement. The bigger the mismatch between the guess and the real feeling, the more it tickled.
So your brain isn’t just “ignoring” your own touch. It is making a very exact prediction, down to the timing and direction, and it only cancels what it predicted exactly. Anything it didn’t see coming gets through.
It’s Not Only Tickling That Gets Turned Down
There is one more detail in that 1999 study that is easy to read past. People didn’t only rate their own touch as less tickly. They also rated it as less intense and less pleasant.
That’s worth sitting with for a second. The brain is not just muting annoying sensations. It mutes the nice ones too, whenever you are the one making them.
Why would it do that? The leading explanation is that it helps you tell the difference between “me” and “not me.” You move your arm a thousand times a day. Your sleeve brushes your skin. Your hair touches your neck. If every one of those felt as loud as a spider walking up your arm, you would never notice the spider. By turning down what you cause, your brain keeps you alert to what you don’t cause.
In other words, tickling works because it’s the one kind of touch your brain can’t write off as “just me.”
Can Anyone Tickle Themselves?
Mostly, no. Scientists have tried hard to find a way around it.
In a 2014 study in the journal Consciousness and Cognition, researchers used a “body swap” illusion. With cameras and a bit of trickery, people were made to feel as if they were living inside someone else’s body. Then they tried to tickle themselves. It still didn’t work. Even when it felt like the other person was moving, their brains still knew who had given the order.
There is one interesting exception. A study published in 2000 by Blakemore and colleagues found that some people with certain symptoms, like hearing voices that aren’t there or feeling that their actions are controlled by someone else, rated their own touch as just as strong as a touch from another person. The researchers linked this to those specific symptoms, not to a diagnosis as a whole. Their suggestion was that the brain’s “that was me” signal may not be working the usual way for these people. It’s a small study, but it shows how much work this quiet system normally does for the rest of us.
Why Do We Laugh When We’re Tickled?
This is the honest part: nobody fully knows.
Tickle laughter is odd. People laugh even when they’re begging you to stop. It’s not quite the same as laughing at a joke. One common idea is that it’s a kind of play signal, a way of saying “this is fun, we’re safe, keep going (but also stop).” It shows up very early in babies, long before they understand jokes.
We are not alone in it, either. The late neuroscientist Jaak Panksepp found that young rats, when tickled by hand, make fast chirping sounds, too high for human ears to hear, and come back for more. Other animals seem to have their own versions too. If you enjoy that kind of thing, you might like reading about how chimpanzee accents show up in their laughter first.
And laughter is not always about fun. Sometimes it pops out when we’re scared or stressed, which is its own puzzle. There’s a good explanation of that in why we laugh in serious situations.
But the tickle kind of laughter has one rule that none of the others have. It needs another person.
The Delight You Can’t Make for Yourself
Think about what all this means in everyday life.
You can feed yourself. You can dress yourself. You can make yourself a cup of tea, sing yourself a song, and tell yourself a joke (though you’ll know how it ends). A lot of life is do-it-yourself.
But not this. There is a kind of joy your own body refuses to give you. It only comes from outside. From a sister who knows exactly where your weak spot is. From a dad chasing a squealing toddler across the room. From a friend who poked you at the worst possible moment. The laugh belongs to both of you, and you could never have had it alone.
There is a very old idea, much older than brain scanners, that the best things in life are not made but received. That joy, like being loved, is a gift that comes to you rather than something you can produce by trying harder. Many people have found that this is exactly how God tends to work too: not as something you manage to squeeze out of yourself, but as a delight that arrives from beyond you, when you stop trying to do it all on your own.
Your cerebellum, it turns out, has been quietly making that point your whole life.
So maybe the next time someone makes you laugh until you can’t breathe, don’t just try to get away. Notice it for a second. That was something you could never have done for yourself. Someone had to give it to you.
Questions People Ask About Tickling
Why can’t you tickle yourself?
You can’t tickle yourself because your brain predicts the feeling of your own movements and turns that feeling down before you notice it. Research from University College London in 1998 found that the brain area that handles touch responds more to a tickle from outside than to a self-made one, and that the cerebellum helps make the prediction. Tickling depends on surprise, and you can’t surprise yourself.
Is it possible to tickle yourself at all?
For most people, not in the usual way. In a 1999 experiment, people tickled their own palm through a pair of robots, and when a delay of about a fifth of a second was added, the touch felt as tickly as a touch from someone else. Most of the 16 people in the study never noticed the delay. A 2014 study found that even a “body swap” illusion did not let people tickle themselves.
What part of the brain stops you from tickling yourself?
The cerebellum, a part of the brain at the back and base of the skull that helps coordinate movement, is thought to predict what your own movements will feel like. That prediction is then used to reduce the response in the brain’s touch area, the somatosensory cortex. Brain scans show less activity there when a touch is self-made than when it comes from someone else.
Why do people laugh when they are tickled?
Scientists are not completely sure why tickling makes people laugh. A common idea is that tickle laughter is a play signal, a way of showing that rough, close contact is friendly and safe. It appears very early in babies. Young rats also make high-pitched chirps when tickled, which suggests tickle laughter may be older and more widespread than humans.
Does your own touch feel less pleasant too?
Yes. In a 1999 study from University College London, people rated touches they made themselves as less tickly, less intense and less pleasant than the same touch made by someone else. The brain seems to turn down most sensations it can predict, not only tickling, which helps it tell apart “things I am doing” from “things happening to me.”
What Do You Think?
Here’s a question for you: what’s something that only ever makes you laugh when someone else does it? A certain face, a certain phrase, a certain friend? Tell us in the comments below.
Share This
- Scientists added a delay of one fifth of a second between people’s movement and their own touch. Suddenly they could tickle themselves. Most never noticed the delay. https://bgodinspired.com/
- You can’t tickle yourself because your brain saw it coming. Some kinds of joy can only come from someone else. https://bgodinspired.com/
- Your brain doesn’t just mute your own tickles. It mutes your own nice touches too. Some things really do feel better when someone else gives them. https://bgodinspired.com/
