Everyone has spots on their body that are particularly sensitive to being tickled. Maybe it’s under the armpits, around your ribs, on your neck – but feet seem to be universally sensitive to tickles. Unbearably so for some.
So, if the sensation of tickling on your feet causes your body to spasm or makes you lash out uncontrollably, don’t worry, you’re not alone. Feet are a hot spot for being hypersensitive to tickling… but most of us don’t know why.
Why is it that the skin on your feet, which is tougher and more hard-wearing than most other places on your body, absolutely can’t cope with the unique pleasure/pain sensation of tickling?
Why is that our feet are so ticklish and our hands, for example, generally aren’t?
Dr Diana Gall, GP at Doctor 4 U, says that despite the toughness of the skin on our feet, they are still one of the most sensitive areas of the body.
‘Our feet hold thousands of nerve endings called Tactile or Meissner’s corpuscles which are found really close to the skin, this is why feet are super sensitive to touch and for many people can be really ticklish,’ Dr Diana said.
‘There are two types of tickling sensations, Knismesis and Gargalesis. Knismesis is essentially the term given for the light tickling sensations, which can be pleasurable for some people or quite uncomfortable for others.
‘Usually Knismesis tickling is the type of pleasant tickle that most people may ask for, for example arm stroking or tickling.
‘Gargalesis describes that type of tickling that produces a reaction of both pleasure and pain which is most associated with heavy tickling, so for example aggressive tickling which can lead to outbursts of laughter but also discomfort.
‘This type of tickling may be perceived by the brain as pain which explains why we often tell the person doing the tickling to stop.’
We all know this kind of tickling. The kind that makes you laugh uncontrollably, even though you’re hating every second. No one can be held responsible for anyone who gets kicked in the face while administering this kind of torture.
You can’t control how you react when you’re tickled because it is usually involuntary.
The sensation of tickling stimulates the hypothalamus in the brain. One of the jobs of the hypothalamus is regulating emotional responses. It also controls your reaction to things that are painful.
So if you laugh, or feel pain or discomfort when your feet are tickled, you may be having an involuntary response generated by the hypothalamus.
It isn’t clear why some people are more susceptible to being ticklish on their feet than others. Scientists don’t have a clear answer, but there are indications that there may be a genetic link.
‘Everyone’s feet are different and will experience different levels of sensations from tickling, however if you find that your feet are becoming less ticklish over time or have become suddenly less ticklish this could be an underlying medical problem such as peripheral neuropathy,’ says Dr Diana.
‘This is a degenerative nerve disease that affects the nerve endings in feet, it can also be caused by medical conditions such as infection, trauma, diabetes and hypothyroidism.’
Another mystery around ticklish feet, is the question of why can’t we tickle ourselves?
Try it now. Bend down and tickle your own foot. It’s incredibly unlikely that it will make you laugh, or give that same pleasure/pain feeling that you get when tickled by someone else, or an object.
Research suggests that the cerebellum – a region located at the base of the brain that monitors our movements – is behind it.
The cerebellum can distinguish expected sensations from unexpected sensations. And scientists believe that sensations have to be unexpected for them to tickle us.
To put it another way, the brain is able to disregard and ignore sensations that it is used to. How it feels to write a text on your phone, or hold a pen in your hand. Whereas it often pays much closer attention to sensations that the body is not used to, or has no control over – like someone tickling the feet.
The reason our brains are so attuned to pay attention to unexpected sensations is likely a response that developed in early human history to detect predators – but now just makes us cry when our other halves touch our feet.