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Humans fear spiders and snakes the most, but find parasites the most disgusting

Spiders evoked the strongest response from the study’s participants, racking up a total of 4.39 points out of 5 for fear and 4.47 points for disgust.

Spiders evoked the strongest response from the study’s participants.
REUTERS/Alexandros Avramidis

Zoophobia — an overwhelming and debilitating fear or dislike of particular animals — is a quite common anxiety disorder, affecting up to 6 percent of people at some point in their lives, according to some estimates.

Many of the rest of us may not have a full-blown case of zoophobia, but we may still recoil with fear or disgust at the sight of certain animals.

The makers of horror movies know that, which is why they so often use creatures to trigger fear — in their on-screen fictional characters and in their audiences.

But which animals do we find most scary and revolting?

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A team of psychologists at National Institute of Mental Health and Charles University in the Czech Republic decided to see if they could find an answer to that question. They surveyed almost 1,800 Czech and Slovakian adults (average age: 33), asking them to rate on a scale of 1 to 5 how frightening or disgusting they found two-dozen animals known to evoke phobia-level responses of fear in some people. Their findings, published recently in the British Journal of Psychology, are intriguing, particularly for what they may tell us about how our instinctive reactions to certain animals help protect us from harm.

Instilling fear

The surveys, which were conducted online, showed the participants photos of ants, bats, bulls, cats, cockroaches, dogs, fish, frogs, horses, lizards, lice, maggots, moths, mice, pigeons, rats, roosters, roundworms, snails, snakes, spiders, tapeworms and wasps. The study also displayed photos of snakes, but because some research has shown that not all snakes are similarly feared, it included two types: a poisonous one and a harmless grass snake. As a “control” animal, the researchers also included photos of pandas (which are not known to be a significant source of zoophobia).

Spiders evoked the strongest response from the study’s participants, racking up a total of 4.39 points out of 5 for fear and 4.47 points for disgust.

Snakes — the poisonous ones, not the innocuous grass snakes — took second place, at least in terms of evoking dread. They earned 4.34 points out of 5 on the study’s fear scale.

“Nearly 19 percent of subjects reported extreme fear or terror when exposed to the spider picture and 10 percent of subjects gave the highest fear score to the viper picture,” the study’s authors write. “This confirms the general agreement in the literature that snakes and spiders are the most intensively feared animals in humans with the highest prevalence in the general population.”

Bulls (3.84 points) were not too far behind, however.

The creatures in the study that elicited the least fear from the survey-takers were snails (1.15), fish (1.15) and cats (1.24).

Instilling disgust

The most disgusting creatures, according to the study’s participants, were parasites, especially the tapeworm (4.83 points), the louse (4.83) and the roundworm (4.79). As the authors of the study point out, all of these creatures can be carriers of serious diseases, such as typhus, cysticercosis and ascariasis.

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The parasites were also fear-inducing, however. The tapeworm, for example, earned 3.60 points for fear — not too far below bulls — and the louse and roundworm were close behind.

But as the researchers point out, it may be “more interesting not to ask which animals trigger high fear and disgust but rather which of them do not.” Of the 24 animals, only 10 triggered a mean score above 3 on either of the scales: the cockroach, grass snake, louse, roundworm, spider, tapeworm, poisonous snake, wasp, and maggot.

British Journal of Psychology
The remaining 14 animals evoked only very little or no fear or disgust. In fact, some scored lower in both categories than the “control” panda. That finding suggests, say the researchers, that many animals associated with anxiety disorders have little effect on most people.

Plenty of caveats

The researchers say their study’s findings support the idea that there are two major kinds of animal phobias, both of which help guard us from danger. One — the phobia represented by our fear of spiders, snakes and bulls — helps keep us at arm’s length from creatures that could maim or poison us. The other phobia — represented by our disgust (and fear) of tapeworms, lice and roundworms — helps protect us from contracting disease.

Of course, like all studies, this one comes with important limitations. It involved a relatively small group of people, for example, and all of them came from the same region of the world. The results might have been different if a more diverse group of people had taken the survey.

Furthermore, the study’s participants were all “self-recruited,” which may mean they were biased toward being interested in the topic of the study — a factor that could have also skewed the findings.

Still, the findings are interesting — and not just because they give us a voyeuristic peek at what other people may be afraid of. The findings also serve as a reminder, say the researchers, that fear is “there to serve a purpose — including to protect us from the creatures that may bite us while we sleep or infect us from within.”

FMI:  You can read the study in full on the website for the British Journal of Psychology.