Why do we fear spiders? More importantly, should we?
By Caitlin Selleck, Class of 2016
Many people can’t stand spiders, and put it down to their hairy bodies, their many legs, or the way they move. Why are we really scared of spiders, how did this fear evolve, and is it still a useful response?
I’ve always wondered why people dislike spiders, probably more than most. No, I’m not a psychologist, I just really like spiders. When someone encounters a spider and they’re searching desperately for the nearest deadly weapon, I’m the one to swoop in and save the poor spider’s life.
This post isn’t just about severe arachnophobia, but the general minor fear or discomfort that the majority of people feel around spiders.
What causes a fear of spiders?
A group of American and Swedish researchers looked at the genetics behind spider fear. They found, by looking at twins, that the fear of spiders can be inherited. If your identical twin is scared of spiders, you are more likely to be. This suggests that your fear isn’t something you learn as a child, but something you are born with.
Considering this, it wouldn’t surprise you to know that children state spiders as their number one fear. Having never felt this fear as a child, I found this statistic surprising. I thought a fear of spiders was something that adults developed, something you only became scared of when you started thinking more about the consequences of a bite.
It was a straightforward idea – certain genes determine your level of spider fear, and I didn’t get those genes. However, it isn’t that simple.
The study of twins found only moderate heritability, meaning there’s more involved than simply genetics. As Graham Davey explains, it is probably a deep rooted cultural disgust, dating back to the Middle Ages when Europeans thought spiders spread the Black Death. This idea is supported by the fact that many non-European cultures aren’t scared of spiders – in fact, they eat them. Because people experience different levels of disgust, and associate spiders with disease, those that have a stronger disgust response often dislike spiders (as well as reptiles and rodents).
But spiders shouldn’t be seen as disgusting. They don’t carry diseases, and unlike many other animals that often meet our disgust, spiders aren’t slimy or scaly. Although your level of disgust is likely genetic, it is a misconception that causes spiders to be lumped in with other animals that actually do cause disease or are associated with it. In fact, spiders are known to be quite clean!
The fear of spiders specifically can be passed from mother to child. Nina Incerti on this very blog site talks more about a study using crickets. Long story short, if a pregnant cricket is scared by a spider, her offspring will avoid spiders and live longer.
The study definitely points to fear being passed from mother to child, but spiders are terrifying predators for crickets. We are much bigger than a spider, can run faster than it, or can pick something up to squish it. And, for most of us at least, we can outsmart a spider! So if this study were to be properly linked to humans, it might explain a fear of big cats instead.
If people think spiders can hurt them (only two Australian spiders are known to kill humans, and no one has died directly from a spider bite since 1981) why do they not fear cats and dogs? Cats have many bad bacteria on their teeth, meaning their bites often cause infection and can hospitalise people. In addition, cats can be grumpy and temperamental. But they are still considered cute and cuddly, and there is no widespread phobia of domestic cats, or larger cats that can easily kill someone with a swipe of their claws. I have both spiders and cats as pets; my cats always scratch me, but I have never been bitten by any of my 18 spiders. So I would say my cats do me more harm.
Why did it evolve?
People have looked into why this reaction evolved in the first place. Some think it began as an evolutionary advantage, and increased safety for early humans.
Humans were more exposed to dangerous spiders in the past. Both humans and spiders related to the Australian red back originated in Africa, so they would have come into contact with one another during day-to-day activities. Perplexingly, all spiders in the black widow genus (including the red back) have venom that is very toxic to vertebrates (animals with a backbone, like fish birds, lizards, and mammals), even though their normal diet consists of insects.
People that feared spiders and could quickly react to one in their peripheral vision would live longer. People still react very quickly if they see a spider out of the corner of their eye, but spiders are no longer very dangerous. Hence, this advantage has become a disadvantage.
What can we do about this?
As with everything, especially scientific topics, education is key. It is important that if you are afraid of spiders, you should try not to pass it onto your kids. Children learn by watching their parents, and if their parents freak out and scream at every spider they see, the children will think this is normal. I’m lucky to have parents who were calm and collected around 8 legged beasts.
An advantage of not killing spiders is that they will eat those annoying flying insects in your house. This may be particularly important if you live in parts of the world where mosquitoes spread nasty diseases. If you really can’t have spiders in the house, you could place them outside, and avoid the mess of squishing something.
Next time you think a spider is ‘coming for you’, think about what you would do if you saw a blue whale. You wouldn’t think “I want to somehow hurt that immense animal”, you would want to avoid it so it doesn’t hurt you. Spiders are the same, they just want to catch food in peace, and if they see a huge animal looming over them they want to run away.
I don’t think it’s an advantage to be scared of spiders today; this is obvious when people talk about overcoming their irrational fear. What I do know is that we should be spending less time spreading spider guts on our walls, and more time admiring their intricate patterns and brilliant web-building skills. Just remember, it’s fine to admire from afar.