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Explainer: why are we afraid of spiders?

I have personal interest in arachnophobia – the fear of spiders – because I am a spider expert, but also because my daughter has it. She is not alone. According to the American Psychiatric Association…

Coming for me next? Pierre J, CC BY-NC-SA

I have personal interest in arachnophobia – the fear of spiders – because I am a spider expert, but also because my daughter has it. She is not alone. According to the American Psychiatric Association, phobias affect more than one in ten people in the US, and of those individuals, up to 40% of phobias are related to bugs (including spiders), mice, snake and bats.

There are clearly a lot of arachnophobes. But do they know why they fear spiders? Can they do something to control those fears?

Once bitten twice shy?

Psychologists believe that one reason why people fear spiders is because of some direct experience with the arachnids instilled that fear in them. This is known as the “conditioning” view of arachnophobia.

In 1991, Graham Davey at City University London ran a study to understand more about this view. He interviewed 118 undergraduate students about their fears of spiders. About 75% of the people sampled were either mildly or severely afraid of spiders. Of those most were female. (This gender bias in arachnophobia has been supported subsequent research.)

There was also an effect from family. Those people fearful of spiders reported having a family member with similar fears, but the study was unable to separate genetic factors from environmental ones. What is surprising is that Davey found that archanophobia wasn’t the result of specific “spider trauma”, which means there was no support for the conditioning view.

So what makes spiders so terrifying? Surely it must be the threat of being bitten? Davey looked at that issue too. It turns out that it is not so much a fear of being bitten, but rather the seemingly erratic movements of spiders, and their “legginess”. Davey said:

Animal fears may represent a functionally distinct set of adaptive responses which have been selected for during the evolutionary history of the human species.

Graham Davey/Anxiety Research

A criticism of Davey’s work is that perhaps “conditioning” cannot be so easily dismissed, because the spider-trauma event may have occurred during childhood, and a specific spider event may be buried deep within memories. In 1997, Peter Muris and his colleagues at the University of Maastricht tried to looked into this.

Not surprisingly, if you give kids a list of things that might be scary for them, the vast majority check off things like not breathing, getting hit by a car, bombs, fire or burglars as quite important. Interestingly, if you give them a free option to tell researchers what sorts of things they fear the most, both boys and girls report “spiders” as their top fear (the second fear is being kidnapped, third is predators and fourth is the dark).

This is surprising. Of all the things kids might report, they list spiders as the number one fear. So in contrast to Davey’s work, Muris finds that the kids that were most fearful of spiders could relate that fear to specific events. Perhaps conditioning is the pathway to arachnophobia.

Muris et al/Behaviour Research and Therapy

Genes or environment?

But before we can be sure that conditioning is the main reason, we need to ensure that genetic factors are not involved too. In 2003, John Hettema at the Virginia Institute for Psychiatric and Behavioural Genetics and his colleagues conducted twin studies to tease apart genetic factors.

Identical twins have identical DNA but tend to live in different environments in adult life, which allows researchers to find out how genes affect behaviour. When Hettema recorded the responses of twins to “fear-relevant” images (spiders, snakes) compared to “fear-irrelevant” images (circles, triangles). Statistical analysis of the results revealed that genetic influences were “substantial”, which means that arachnophobia is inheritable. You need not necessarily experience spiders to be fearful of them.

Peacock spider Jurgen Otto, CC BY-NC-ND

Scare tactics

So, to my dissatisfaction, arachnophobia is here to stay. But there may be a simple technique to reduce the fear these bugs cause. In 2013, Paul Siegel at the State University of New York and his colleague published a study that helped volunteers lessen their arachnophobia.

They first split the volunteers into phobic and non-phobic groups, based on simple spider-fear tests. After a week of doing these tests, both the groups were then given exposed to images of flowers or spiders, but the exposure was for such a very short time.

The idea was that people can’t recognise the images consciously, but it has an effect on their subconscious. When the spider-fear tests were carried out on both these groups again, those who feared spiders had become less afraid.

While other general conclusions are hard to draw from the literature on arachnophobia, arachnologists like me should rejoice at the results of Hettema’s study. If nothing else, at least sharing images of spiders may help reduce arahnophobia.

Update: I built something to help you reduce your fear of spiders

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20 Comments sorted by

  1. Tracy Nelson

    support worker

    An interesting article. You might be glad to know that I have rescued many a spider from the impulsive reaction to stomp on them

    I personally think people can train themselves to react differently. I grew up having the usual fears about them and this was mainly to do with the strong reactions to walking into their webs and them being on/or possibly getting on me. I was realistically fearful to some degree about being bitten since I grew up in an area that had plenty of funnel-webs, but overall it was the creepy crawly aspect of them that drove my bias toward them.

    I had always been against harming creatures unnecessarily so when I came to realize quite early in the piece that most spiders are harmless I tried hard to compartmentalize my reactions. While I still couldn’t stand walking into their webs or liked the thought of having them on me etc I ceased allowing these responses to influence the way I treated/viewed them.

    1. Chris Buddle

      Associate Professor at McGill University

      In reply to Tracy Nelson

      Thanks, Tracy, for your comments! Very interesting and insightful. I agree with you that people can often train themselves to work through mild Arachnophobia. Great stuff!

  2. Deborah Cowell


    I am very interested in this, especially as we don't have poisonous spiders in the UK, so why the fear.
    I did wonder if inherited fear had something to do with epigenetics, and the activation of an instinctive fear. However, since most fears seem to centre on the way that spiders move, then maybe it is the natural fear of the unpredictable and otherworldly. Could it be that spiders have evolved a way of moving that is not just efficient, but protects them from larger creatures, which instinctively avoid them? Those with the most scary, scuttly movements survive the longest, as we jump away, rather than stomp.

    1. Chris Buddle

      Associate Professor at McGill University

      In reply to Deborah Cowell

      Thanks for the comment, Deborah! Great thinking on the topic - it does seem that the combination of movement and legginess is what causes a lot of the fear, and surely there's an evolutionary basis for this.

  3. Paul Redfern

    Ukulele player at the pUKEs

    I too found this a most interesting article. I don't suffer from arachnophobia except at 2nd hand: I live with an utter arachnophobe. I'd love to be able to share this article with her. Unfortunately, it is littered with images of arachnids, the creature she most fears.
    Not the author's fault I'm sure, but the way his story is laid out, I suspect he may find himself preaching only to the converted ;)

    1. Alan Howe

      logged in via Facebook

      In reply to Paul Redfern

      Absolutely right Paul - I wanted to send this to my arachnophobic daughter but she wouldn't thank me for it - she wouldn't get past the first photo of the spindly spider.

    2. Chris Buddle

      Associate Professor at McGill University

      In reply to Alan Howe

      Thanks for the comments, Paul and Alan. I appreciate your thoughts on this. To be honest, this article was about arachnophobia rather than for arachnophobes, but you make a valid point in that some arachnophobes may be keen to read some of this. If you can drop me an email at chris dot buddle at mcgill dot ca I will be happy to send you a PDF of the text without any images.

  4. Will Hunt


    A good healthy pasture has a resident population of somewhere around 100,000 spiders to the hectare- admittedly very small, most of them. And they work 24/7 tirelessly cleaning up bugs and mites, and Shell oil, Monsanto and their ilk don't make a cracker out of them. I think they are marvellous, especially when you look out on a winters morning, and see acres and acres of spiders webs glinting in the dewy light, quite beautiful.

  5. Sylvia Gonggryp

    logged in via Facebook

    Interesting article, indeed. I tend to believe that arachnophobia indeed represent a functionally distinct set of adaptive responses which have been selected for during the evolutionary history of the human species. It sounds logical to me that it’s something in our DNA. Spiders can be toxic, especially to infants. That explains the gender bias in arachnophobia. Maybe increased by the social environment in which young girls increase each others fear, and where it is more accepted to be afraid as…

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  6. Jennifer Soto

    logged in via email

    I think trying to explain why people fear spiders for any reason other than a personal experience with a spider is pointless. It would be like asking people why they like certain colors. they aren't too sure, they just know they do. The results are interesting though.

    I think they should have focused more on why people are scared of them for any reason instead of just on those that didn't have a personal experience. I am severely phobic due to a spider bite I dealt with as a child. When I was maybe…

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    1. Chris Buddle

      Associate Professor at McGill University

      In reply to Jennifer Soto

      Thanks for the comment, Jennifer: I think Arachnophobia, like many other phobias, has both a genetic and environmental basis - that's certainly what the literature supports. That being said, the personal experience is, at the individual level, very important and is certainly a driver for the broader interest in spiders. In other words, *everyone* has a story about spiders! Some positive, some negative.

  7. Mats Uldal

    Neurotapping therapist

    I have cured hundreds of people with arachnophobia during the 17 years I have worked (in Norway) with Thought Field Techniques(TFT) or Neurotapping.
    I have found that people are very seldom afraid of what they say they are afraid of. By using some questioning techniques I have developed we can get to the fundamental root cause in minutes. A spider phobia does not have to do with spiders at all. One lady were afraid of small, quick spiders, the worst part with those were they could jump on her, and…

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    1. Chris Buddle

      Associate Professor at McGill University

      In reply to Mats Uldal

      Thanks for the comment, Mats: it is a very interesting perspective, and although I agree that some (many, perhaps!) instances of arachnophobia may be due to other factors, I also think that many people are fundamentally fearful of spiders, because of the factors mentioned in the post (many legs, the way they move, etc).

  8. Donna Chasteau

    Home Educator

    I was convinced arachnophobia was nurture not nature so although I'm not a fan, equally I'm not phobic and never showed fear in front of my kids when collecting them in a bug box to put outside. I chatted to them, telling them to go and find their mummy (or babies, if it was a biggy). One day when my daugther was 5 ish, I spotted a beautiful web outside the kitchen window and a small insect had flown in to it. I told my daughter how lovely it was and look at how the spider would wrap it up. FYI…

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    1. Chris Buddle

      Associate Professor at McGill University

      In reply to Donna Chasteau

      Thanks for the comment, Donna - what you write is really very interesting, and points to the very real and serious nature of arachnophobia. Thanks for sharing!

  9. Ray Mainiero

    logged in via Facebook

    Thanks for the very interesting article.

    I grew up with an unexplainable fear of spiders. Just seeing a spider would throw me into a panic, while ironically, I had no fear of just about anything else. Growing up my childhood friends found this to be hilarious.

    When I was 20 years old in the Marine Corps while doing bivouac on an island island off the coast of Puerto Rico I had to dig a foxhole during a bivouac drill. Sure enough, a huge tarantula came out of a hole! I went into a panic and started beating it with my shovel, eventually killing it. I figured there might be another one hiding so I dug further, and eventually came across another smaller one that scurried into a hole. I gave up on the foxhole and sat underneath a palm tree as the inspecting party came by.

    Interestingly, after that experience I no longer had a fear of spiders. Now at 78, I let spiders crawl up my arm allow my five-year-old granddaughter do the same.

    Ray Mainero

    1. Chris Buddle

      Associate Professor at McGill University

      In reply to Ray Mainiero

      Thanks for sharing your experience, Ray! It's really interesting that the experience cured your fear of spiders. When working with arachnophobes, I have found that sometimes just calm discussion about spiders, and 'controlled' experiences with spiders (i.e., first looking at small ones in a vial, followed by larger ones, and then maybe watching some in nature, etc) can really help people get over some of their fears. Your experience sounds MUCH more dramatic than that!

  10. Madelyn Boudreaux

    logged in via Facebook


    I am a lifelong spider lover. I WAS bitten as a child (for handling a jumper that I wanted to rescue from certain death), but all that did was instill in me a healthy respect for the bite and a realization that the bite isn't THAT bad.

    These days, I photograph spiders (and other arthropods) as a hobby. Any time I post a new photo to Facebook, I have to deal with at least one phobic reaction. I've made a Arachnophobes filter to protect these folks. I've lost a few friends over the issue.

    In anecdotal support of this article, I've had some friends who, although they are phobic, have pushed through their fear - either b/c they like my photos, or for other reasons. Several of them have said that my photos have helped them to see spiders as beautiful and have learned to accept spiders in their lives as a result.

    1. Chris Buddle

      Associate Professor at McGill University

      In reply to Madelyn Boudreaux

      Thank you for the comment Madelyn - I really appreciate your kind words! Yes, I do think that mild arachnophobia can be worked through, and is often about education. Sharing photos, stories, etc. can really be an excellent way for folks to "get to know" spiders, and see them as friends not enemies!