by Katherine Enright, Sophia Hall, and Karla Rigan
Scientists gather information on the human fear of bugs
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YELP! A spider is found sharing your shower or lodging in the corner of your room!
Do you…
Leave him be, mi casa is tu casa. Maybe ask him for help with the rent.
Call your brave friend to bring him out of the room
Take matters into your own hands and grab your least favorite shoe
Here’s this itty-bitty creature that we are so much bigger than, yet you’re screaming in the shower. Have you ever heard someone say, that spider is more afraid of you than you are of it? Whether you're the brave one or the scaredy cat, this fear of insects is so prevalent in our lives and can cause us to shake in our boots, even though most insects are harmless. Let's talk about that.
Back in the dawn of time, our human ancestors had to have a healthy fear of creatures that posed a threat to their life. This is a tough task, but our cool human brains have great responses of fear and disgust to stay away from things that are going to kill us. Our ancestors did a good job at this avoidance behavior; hence we are still alive. But I'm sure there were some close calls, like a caveman toddler coming home with a black widow as a pet. For the most part, however, if a human back then had a fear of insects, they were most likely to survive due to natural selection. Only the ‘fittest’ (especially when it comes to knowing which bugs are dangerous) survived. These days, however, humans seem to have a fear of insects that really hurts more than it helps. A lot of people have an irrational fear of insects, which is called a phobia. We scream or hide or kill insects that really can’t do us any harm.
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Researchers at the Faculty of Science at Charles University and the Czech Republic National Institute for Mental Health were particularly interested in this irrational fear that humans have of bugs, especially when that fear is only directed at spiders, which is called arachnophobia. Because who isn’t afraid of spiders? In this study, these researchers were thinking that maybe it’s our caveman ancestors, and their healthy fear of bugs that are at the root of the irrational fear of spiders.
Spiders and insects belong to the category of invertebrate animals called arthropods. Spiders differ from other arthropods such as ants because they have no antennae, two body segments instead of three, and special mouthparts. Because of these differences, they are considered to be chelicerates, a subdivision of arthropods. This group includes daddy long legs, ticks, spiders, and scorpions. So, our researchers thought it’s important that scorpions are in the same group as spiders. Scorpions, unlike spiders, are very dangerous to humans because their stings can kill you. Our researchers thought that maybe throughout time, humans have grouped spiders and scorpions together in our minds, so the irrational fear of spiders comes from the rational fear of scorpions.
Although this is really hard to prove, our researchers thought they could test whether it was a plausible hypothesis. To test this out they had people rate different arthropods of scales of fear, disgust, and beauty. They hypothesized that all chelicerates, including spiders and scorpions, would rate closest together on the fear and disgust scales, and also higher than all the other arthropods. They also figured that the bigger the arthropod was, the higher it would rate on the fear and disgust scales. They wanted to prove that the more dangerous an arthropod looks, (hefty or like a scorpion), the more fear and disgust it will elicit.
Our researchers selected different arthropod species to be the stimuli, or the objects they wanted the participants to react to. They chose these arthropods based on the size, whether they looked dangerous, whether they were dangerous, and the creature’s natural habitat. There was a lot of variety in the chosen arthropods, and they ended up working with 62 species from eight different arthropod groups. Next, they brought in 329 adults, both male and female and asked them to rate each arthropod on scales of fear, and beauty. On a scale of one to ten, how scary is this spider, scorpion, cockroach, etc.?
[3] Modified version of Figure 1 from Frynta et al. (2021)
(click on figure or link to left for clearer view)
The results were these...all chelicerates elicited the most emotion, meaning they scored highest on the fear and disgust scales. The bigger the arthropod, the higher it scored also.
Whew! They found some truth in what they were looking for. People are really scared and disgusted by spiders and scorpions, more so than any other arthropod. Sorry cockroaches, try again next year at the costume contest. This seems to point out that fear and disgust can be generalized. This arthropod and that arthropod look alike, if you fear one, you are going to be scared of the other.
So, what does this mean? These researchers want to talk more about the possible shared origins of the fear of spiders and scorpions. Although they can’t prove it, there is something compelling about these details.
So, the next time you scream when you see the spider sharing your shower, just relax and tell yourself it's probably just your inner caveman, fighting for your life.
Further Reading
Frynta, Daniel, et al. “Emotions Triggered by Live Arthropods Shed Light on Spider Phobia.” Scientific Reports, vol. 11, no. 1, Nov. 2021, p. 22268. www.nature.com, https://www.nature.com/articles/s41598-021-01325-z.
