Brain Trick
Ambidexterity
Using both hands equally well for every task. Fewer than 1% of people are truly ambidextrous. Most people who say they are ambidextrous are mixed-handed: right hand for some jobs, left for others.
Under 1%
Trick
Things some people can do on command. Some are learnable; others appear to be innate.
27 oddities.
Mouth Trick
Cloverleaf tongue
Folding the tongue into three lobes, like a clover leaf. Between 10% and 15% of people in Western samples can do it. It is usually called the hardest tongue shape.
10–15% (Western samples)
Eyes Trick
Crossing your eyes
Turning both eyes inward toward the nose on purpose. Nearly everyone with normal two-eyed vision can do it. Your eyes will not get stuck that way.
Nearly everyone
Ears Trick
Ear rumbling
About half of all people can make a low roar inside their own head by tensing a tiny muscle in the middle ear.
43–55% of people
Ears Trick
Ear wiggling
Moving the outer ears using three small muscles that most mammals use to point their ears at sounds. Between 10% and 22% of people can wiggle at least one ear. Many more can learn.
10–22% (one ear)
Eyes Trick
Eyelid flipping
Turning the upper eyelid inside out so the pink inner surface shows. Most people with reasonably loose lids can learn it. Eye doctors do it to patients to look for grit.
No formal count Icky
Muscle Trick
Flaring your nostrils
Widening the nostrils on purpose. About 30% of people can do it on command. Everyone does it without thinking during hard breathing and strong emotion.
~30% on command
Mouth Trick
Gleeking
Shooting a thin jet of saliva from under the tongue, sometimes a metre or more. About 35% of people do it by accident now and then. Only about 1% can do it reliably on command.
~1% on command Icky
Mouth Trick
Gorlin's sign
Touching the tip of your nose with your tongue. About 10% of people can do it. About half of people with Ehlers-Danlos syndrome can, so doctors use it as a quick check for stretchy connective tissue.
~10% of people
Heart Trick
Heart rate control
Slowing or speeding up your own heartbeat on purpose, using breath, attention, or training. Most people can shift it a little within minutes. A few trained people shift it a lot.
Most people, a little
Eyes Trick
Independent eye movement
Moving one eye while the other stays still, or moving the two eyes in different directions. Very rare in humans. Chameleons do it all day.
Very rare; no formal count
Mouth Trick
Khechari mudra
A hatha yoga practice in which the tongue is turned back and up behind the soft palate, into the space at the back of the nose. Very few people can do it without months or years of stretching.
Very rare without training
Bones Trick
Knuckle cracking
Pulling or bending a finger joint until it pops. Between 25% and 54% of people do it out of habit. The sound is a gas bubble forming in the joint fluid, and it does not cause arthritis.
25–54% crack habitually
Bones Trick
Midtarsal break
A foot that bends in the middle, between the heel and the ball, as well as at the toes. About 1 in 13 people have it. It is a leftover from tree-climbing ancestors.
About 1 in 13 (7.7%)
Muscle Trick
Platysma display
Tensing the thin sheet of muscle under the skin of the neck so that cords stand out from jaw to collarbone. Everyone has the muscle. Isolated control of it is uncommon.
No formal count
Mouth Trick
Pointed tongue
Making the tip of the tongue narrow and sharp, like a pencil point. About 55% of people can do it. After rolling, it is the most common tongue trick.
~55%
Muscle Trick
Raising one eyebrow
Lifting a single eyebrow while the other stays down. Between 30% and 35% of people can do it without training. Most of the rest can learn it in front of a mirror.
30–35%
Mouth Trick
Tongue folding
Folding the tip of the tongue backward over itself inside the mouth. Between 14% and 27.5% of people can do it.
14–27.5%
Mouth Trick
Tongue rolling
Between 65% and 84% of people can curl the sides of the tongue up into a tube. For decades it was taught as a simple one-gene trait. It is not.
65–84% of people
Mouth Trick
Tongue twisting
Turning the tongue on its side so the edges face up and down, or all the way over. Between 12% and 36% of people can twist it at least halfway.
12–36%
Organs Trick
Voluntary burping
Swallowing air on purpose and letting it back up as a belch. Most people can learn it. The loudest recorded burp is louder than a motorcycle.
Most people can learn it
Ears Trick
Voluntary Eustachian tube opening
Opening the tubes that link the middle ear to the throat on command, without swallowing or pinching your nose. You hear a click, and your own voice gets loud. Divers and frequent flyers learn it.
Many can learn it; no formal count
Bones Trick
Voluntary joint dislocation
Pushing a joint partly or fully out of its socket on purpose, then back in. About 20% of people have some joint hypermobility. True voluntary dislocation is much rarer and often linked to a connective tissue disorder.
Rare; no formal count Icky
Eyes Trick
Voluntary nystagmus
Between 5% and 8% of people can make both eyes shake rapidly from side to side on command. It looks alarming and is harmless. It is tiring and lasts only seconds.
5–8% of people
Skin Trick
Voluntary piloerection
Giving yourself goosebumps on command, without music, cold, or fear. About 1 in 1,500 people can do it. The muscles involved are not supposed to take orders.
About 1 in 1,500
Eyes Trick
Voluntary pupil control
Changing the size of your pupils by will alone, without imagining a light or doing sums. Only a handful of cases are documented. Indirect control by thinking hard is possible for almost everyone.
A handful of documented cases
Eyes Trick
Wall-eyed divergence
Turning both eyes outward, away from the nose, on purpose. It is much rarer than crossing the eyes. Most people can learn a mild version through Magic Eye pictures.
Rarer than crossing; no formal count