Arachnophobia in four acts

6 May 2014 by Christopher Buddle, posted in Outreach, Research, Spiders

I have a personal interest in Arachnophobia (fear of spiders): my daughter is very fearful of spiders, but I clearly am not. This is quite curious, and a bit distressing for me! My daughter is not alone: according to the American Psychiatric Association (1994), phobia’s affect 10-11% of the population in the USA, and of those individuals, up to 40% of phobias are related to bugs (including spiders), mice, snake and bats. There are a lot of arachnophobes out there, giving me more and more reasons to continue my crusade for education about Arachnology. I must admit, however, that I have not done a lot of research into the basis of arachnophobia, and don’t know the literature as well as I should. I decided to remedy this by reading some papers about the fear of spiders, and thought I would share some of these with you, in four acts.
....not for the arachnophobic (photo by Sean McCann, reproduced here with permission)

....not for the arachnophobic (photo by Sean McCann, reproduced here with permission)

Act 1: A conditional fear of spiders?

Davey (1991) wrote a truly fascinating paper titled “Characteristics of individuals with fear of spiders”. Based on a series of surveys, Davey’s goal was to assess the shared characteristics of people who have a fear of spiders, and to understand (and challenge) what is the classical ‘conditioning’ view of Arachnophobia (i.e., some kind of direct experience with spiders instilled a life-long fear of arachnids).  One of Davey’s surveys involved asking 118 undergraduate students about their fears of spiders, and of that number, 85 had, at one point in time been afraid of spiders or were presently afraid of spiders. 75% of the people sampled were either mildly or severe afraid of spiders! Of the total that were currently afraid of spiders, over 55% of the female respondents were arachnophobic where only 18% of the male respondents were scared of spiders (this gender bias in Arachnophobia has been subsequently supported many times over). There was also an effect of family: those people fearful of spiders reported having a family member with similar fears (but the study was unable to separate genetic- versus environmentally-based fear). In contrast to conditioning fear, Davey reports little effect of any specific ‘spider trauma’ as the reason for Arachnophobia.

Why people are scared of spiders (From Davey 1991) [data are % of respondents for different characteristics]

Why people are scared of spiders (From Davey 1991) [data are % of respondents for different characteristics]

What makes spiders so fearful? Surely it’s the threat of being bitten? Thankfully, Davey presents results about this as well. I was pleased to see that this sample reflects my experience also - it’s not so much a fear of being bitten, but rather the seemingly erratic movements of spiders, and their ‘legginess’ (as an aside, that extra set of legs is reported to affect entomologists, too, as reported by Vetter in 2013).   In sum, Davey’s excellent paper more-or-less provides support  "...that animal fears may represent a functionally distinct set of adaptive responses which have been selected for during the evolutionary history of the human species”.

Act 2: What about the children?

A criticism of Davey’s work is that perhaps ‘conditioning’ can’t be so easily dismissed because the ‘spider trauma’ may have occurred during childhood, and a specific spider event may be buried deep within memories. It’’s therefore quite fascinating to read the work by Muris et al. (1997), who tried to figure out what children in the Netherlands are afraid of.  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 truly stunning: of ALL the things that kids might report, they list spiders as the number one fear. In contrast to Davey’s work, Murius et al. find that the kids that were most fearful of spiders could relate that fear to specific events. Stated another way, conditioning was the likely pathway to arachnophobia.

What children are afraid of, when you ask them (from Murius et al 1997) [data are as a %]

What children are afraid of, when you ask them (from Muris et al 1997) [data are as a %]

Act 3: Genetics or environment?

I was quite excited to read the paper by Hettema et al (2003) which has significantly furthered our understanding about whether there is a genetic basis to Arachnophobia. In this work, the authors used a ‘twin study’ (i.e., comparisons of reactions between twins allows for the understanding genetic underpinnings given the genetic similarity among the twins) and looked at conditional fear responses to ‘fear-relevant’ images (spiders, snakes) compared to ‘fear-irrelevant’ images (circles, triangles). The authors document that there was “substantial genetic influences, with additive genetic effects accounting for between 34% and 43% of the total variance in our best fit models”.  I find this quite astounding, and I think it helps to explain both the high prevalence of arachnophobia in the general population, and why this arachnophobia persists. Again, there is support for the theory of some evolutionarily, adaptive basis for arachnophobia, and this is heritable: you need not necessarily experience spiders to be fearful of them.

Cute & fuzzy jumping spiders! Don't fear them! (photo by Sean McCann, reproduced here with permission)

Cute & fuzzy jumping spiders! Don't fear them! (photo by Sean McCann, reproduced here with permission)

Act 4: What to do about arachnophobia?

Based on the first three acts, perhaps there is reason for me to give up hope: arachnophobia is significant, and here to stay. A rather significant percentage of the population (especially women and children!) is fearful of spiders, and there certainly seems to be some genetic basis for this fear.  Thankfully, however, there seems to be some rather simple and straightforward techniques that might be used to lessen Arachnophobia, and this is where the paper by Siegel & Warren (2013) enters our story. In this work, the authors used a standard “spider fear questionnaire” and a behavioural avoidance test (which essentially assessed people’s avoidance of a tarantula in a terrarium) to place people into either spider phobic or non-phobic groups. One week later, individuals were exposed to a “VBE” test (very brief exposure): the test either showed imperceptible images of either flowers or spiders (i.e., this could be called ’subliminal’ in that images were shown to people so quickly in a series that the effect was on the subconcious). After this exposure, the behavioural tests were done again. Low and behold, the arachnophobic group became less fearful of the tarantula in a tank the terrarium.  This work has some interesting implications, and as the authors state “...VBE may be useful as an initial adjunctive treatment that reduces fear enough for treatment resistant phobic individuals to be willing to engage in exposure treatment, getting them ‘‘over the hump’’”. In other words, this approach may be a non-fearful way to help Arachnophobic individuals overcome their fear of spiders. Perhaps Arachnologists around the world ought to lobby movie-makers into inserting frames of spiders into all hollywood films….


It’s hard to draw many generalities from the literature on Arachnophobia, although quite clearly conditioning is likely important in some children, spiders elicit strong responses in many people, there is likely some genetic basis to arachnophobia, and females tend to be more fearful of spider than males. There are some interesting clinical approaches to deal with arachnophobia, and you could argue that sharing images and stories about spiders may help reduce arahnophobia. Good: I’ll keep on writing about spiders on this blog! 


American Psychiatric Association (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington: American Psychiatric Association.

Davey (1991) Characteristics of individuals with fear of spiders, Anxiety Research, 4:4, 299-314, DOI: 10.1080/08917779208248798

Hettema et al. (2003). A Twin Study of the Genetics of Fear Conditioning. Arch Gen Psychiatry. 2003;60(7):702-708. doi:10.1001/archpsyc.60.7.702 

Muris et al. (1997) Common childhood fears and their origins. Beh. Res. Ther. 35(10): 929-937

Siegel, P. & R. Warren (2013) The effect of very brief exposure on experienced fear after in vivo exposure, Cognition & Emotion, 27:6, 1013-1022,

Vetter, R. (2013). Arachnophobic Entomologists: When Two More Legs Makes a Big Difference. American Entomologist Volume 59, Number 3, Pages pp. 168-175

7 Responses to “Arachnophobia in four acts”

  1. Graham Reply | Permalink

    Hi, I was very phobic and it had started to interfere with daily life (not wanting to move things in the loft or garage etc). Then I took a course of serotonin reductase inhibitors and as a welcome side effect became less fearful of a number of things, including spiders. Is this common?

    • Christopher Buddle Reply | Permalink

      Thanks for your comment, Graham: to be honest, I don't know much about the role of serotin reductase inhibitors. I will look into this.

  2. Will Holz Reply | Permalink

    "the arachnophobic group became less fearful of the tarantula in a tank."

    I love spiders, but I find the idea of a tarantula driving a tank terrifying.


  3. Debby Schade Reply | Permalink

    I was afraid of spiders as a child, but as I learned more about them, my fear became less. Now I just find them fascinating! Such incredible creatures! (I even had a "pet" tarantula at one time, a female named "Harriet"--because she was hairy! I let her sit on my hand and cllimb up my arm!) I believe people fear things they don't understand, especially critters that may bite them! Education is the key to decreasing this unfounded fear. Thanks for a great post, Prof. Buddle!

    • Christopher Buddle Reply | Permalink

      Thanks for the comment, Debby! Much appreciated. Amazingly, our 'lab' tarantula is also named Harriet. I agree with you wholeheartedly - education is key.

  4. Alex L Reply | Permalink

    Interesting set of studies, thanks for collecting them.

    I was so terrified of spiders as a kid that I had trouble using the dictionary to look up S and T words because it had tiny pictures of a spider and a tarantula. Maybe it was the legginess, especially since I didn't have issues with insects. Now I'm fascinated by spiders, especially jumping spiders. Education had a big part at least for me. I studied ecology and biodiversity as a undergrad, eventually I got to the arachnids part of intro zoology and got to hold a tarantula during lab.

    I volunteer at a science museum now, where I get to handle snakes and I try to encourage people to overcome their fear of them. Even though I can relate, I'm sometimes at a lost to offer encourage words to some very frightened people.

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