Does the look of baby Swiss cheese give you the heebie jeebies? What about the little

air bubbles in a frying pancake, or the inside of a wasp nest, or the patterns in this coral,

or this lotus pod?

Does this image make you throw up a little in your mouth? Well then, friend, you may

have trypophobia -- the fear of clusters of small holes.

Phobias are persistent, irrational fears of particular objects or situations, the causes

of which are often unknown.

In the bigger picture, being afraid of holes isn't that weird. I mean, people are afraid

of all sorts of crazy stuff. One etymologist has been collecting the names of phobias for

nearly thirty years, and his list currently contains hundreds of odd fears, including

fear of the moon, of beards, of pooping, puppets, numbers, vegetables, bicycles, beautiful women,

the color purple ... you name it.

But trypophobia isn't on the list. It's not yet officially recognized as a legitimate

phobia, despite the fact that an estimated 15 percent of people feel it to some degree.

The term itself popped up in the mid-2000s when internet users randomly began posting

images of hole-y things and comparing their aversions to clusters of small holes.

And then for close to a decade, typophobia seemed to just be some weird viral internet

thing, but recently psychologists Geoff Cole and Arnold Wilkins at the University of Essex

in England, decided to research its validity.

After comparing a variety of benign images with pictures of all sorts of things that

grossed people out, they found that the most offending images shared a common underlying

mathematical structure. Namely, they featured lots of small, highly-contrasting details,

like stripes, dots, or holes, that were spaced apart in fairly close, regular patterns.

For example, in this lotus pod, there's a high contrast between the dark holes and the

light surface, and the holes are spaced evenly enough to highlight those details, while creating

a repeating sequence that, apparently, makes some people want to puke.

Wilkins and Cole maintain these patterns are similar to those found in certain venomous

animals like the blue-ringed octopus, and various spiders and snakes.

They speculate such images trigger something in the non-conscious brain that lights up

a reflexive warning, saying "Hey! Hey! Hey! That's dangerous!" before the conscious brain

can step in and say, "Dude, that's just Swiss cheese."

If Wilkins and Cole are right, it would suggest that trypophobia is a lingering remnant of

some earlier, useful evolutionary adaptation -- namely, stay away from venomous things.

Another theory is that holes in organic objects subconsciously trigger thoughts of contagious

diseases or skin illnesses like rashes and boils, lesions, and pox -- things that are

dangerous to our health. So perhaps the fear of holes is a lingering evolved trait that

once helped us avoid disease.

What I find most interesting though, is that trypophobia may also be a so-called emotional

contagion, essentially meaning that it can transfer to more people as they become familiar

with it. Like, maybe if an hour ago I asked you if you were skeezed out by little holes,

you would have been like, "What are you talking about?".... but now, after hearing about it

and seeing some of these pictures, you know exactly what I'm talking about.

In which case, sorry.

But still, there are some people for whom all you have to do is say, "Hey, look at these

little holes" and then they totally puke all over you. For those types, the revulsion is

clearly pre-existing.

For now, the true nature of trypophobia is a matter of speculation, but still, I'll bet

some of you viewers just lost your appetite.

Anyway, thanks for watching this SciShow Dose! If you'd like to help us keep exploring the

world, just go to Subbable.com/scishow to find out how you can become a supporter.

And if you wanna keep getting smarter with us, don't forget to go to YouTube.com/scishow

and subscribe!