Why Do So Many People Fear Spiders?

You get up one morning and wander into the bathroom, still bleary-eyed and half asleep. You pick up your toothbrush and turn on the tap, and suddenly a wolf spider the size of your hand comes catapulting out of the drain, clearly bent on murder. Do you, A) stare with curiosity at this huge creature that only moments ago was hiding inside a very small drain pipe or B) lose your freaking mind.

Most people will probably choose "B" because spiders are terrifying, terrifying, harbingers of ... what? Do you even know why you're afraid of them?

You've probably been afraid of spiders your whole life

According to The Independent, scientists still haven't nailed down precisely what it is that makes the average person so petrified of such a disproportionately small creature. LiveScience says that there are 40,000 different kinds of spiders in the world, and only a few of them are actually dangerous to humans, so it's hard to believe that the fear is based entirely on the possibility of a painful or deadly spider bite. For a while, scientists thought that people had to be conditioned to fear spiders — in other words, there had to be some spider-related event in a person's past that made them develop an irrational fear of all spiders. 

Research hasn't really shown that's true, though. In 2003, researchers at the Virginia Institute for Psychiatric and Behavioral Genetics did a twin study (because what aren't twin studies good for, really?) that seemed to show arachnophobia has a genetic component, so yes, you might actually be born with a fear of spidersRecent tests with human infants seem to confirm this — as it turns out, babies as young as six months will have a measurable fear response when viewing images of spiders. 

You might be afraid of spiders because they're gross

Some psychologists think it has to do with your "disgust sensitivity," or your reaction to things you find repulsive. This is a response that evolved in humans to help protect us from things like bad food and disease-transmitting substances like barf and poop. For some reason, people react to spiders with this same disgust response — maybe because spiders through history often lived in the same dark places as disease-spreading rats, which made people incorrectly associate them with plague and other horrible illnesses. Or maybe it's just because they're super-creepy, what with all the extra eyes and legs.