Phobia of the Week: Arachnophobia

Objects in phobia are smaller than they appear. WIN-Initiative/Getty

Let's talk about your fear of spiders, shall we?

The mere sight of an eight-legged horror starts your sweat pouring and your nerves tingling.

Heck, the mere glimpse of a spider in a horror movie is enough to send you screaming out of the theater.

No, I'm not going to show you a video of a monstrous spider. Not yet. First, let's discuss the science...

Evolved Arachnophobia

Only 0.1 percent of the 35,000 different kinds of spiders in the world are poisonous, but such creeping killers as the black widow and the brown recluse are certainly enough place all arachnids on the suspect list. So evolutionary biologists have long wondered if our fear of spiders is hardwired. In 2001, a Swedish study made a case for an in-born spider aversion through an experiment involving flashcards of fearful and non-fearful images. According to the study (detailed here), a statistically significant number of subjects identified the pictures of spiders (and snakes) more swiftly than they did pictures of flowers and the like. Subjects who claimed to suffer from arachnophobia identified the spiders even faster.

Toddlers vs. Spiders

So does that mean we are, in fact, born with an aversion to spiders? Not so according to a 2011 study published in Current Directions in Psychological Science. The researchers found that infants reacted the same to images of both fearful and non-fearful animals. With slightly older children, they found that subjects who were afraid of snakes or spiders quickly identified fearful animals, but so did the fearless subjects. So the take-home seems to be yes, we're programed to detect spiders very quickly, but the fear component is something we learn.

Giant Spiders of the Mind

And just how big is that spider haunting the bathroom you refuse to use anymore? Probably smaller than you think. According to a 2012 study from Ohio State University, the greater the arachnophobia, the larger the spider appears to be. The study involved 57 arachnophobes, each of whom was asked to rate their fear response to a spider in a glass tank. Then they were asked to estimate its size. Higher average peak ratings of distress during the spider viewing lined up with overestimations of the creature's size -- and vice versa.

Now I think we can safely begin immersion therapy, assuming you don't want to see an actual doctor or try out some virtual reality therapy.

About the Author: Robert Lamb spent his childhood reading books and staring into the woods — first in Newfoundland, Canada and then in rural Tennessee. There was also a long stretch in which he was terrified of alien abduction. He earned a degree in creative writing. He taught high school and then attended journalism school. He wrote for the smallest of small-town newspapers before finally becoming a full-time science writer and podcaster. He’s currently a senior writer at HowStuffWorks and has co-hosted the science podcast Stuff to Blow Your Mind since its inception in 2010. In his spare time, he enjoys traveling with his wife Bonnie, discussing dinosaurs with his son Bastian and crafting the occasional work of fiction.