Is the fear of spiders wired in by evolution or picked up from culture?
In lab tests, people spot a spider hidden among flowers faster than a flower hidden among spiders, and a fear of spiders can be conditioned after a single pairing. Yet in parts of Papua New Guinea and Cambodia spiders are a traditional food, which complicates any story of an inborn terror.
Arachnophobia, from Greek words for spider and fear, covers spiders and related arachnids such as scorpions and ticks. It is a specific phobia and one of the commonest anxiety disorders, affecting an estimated 3.5 to 6.1 per cent of people worldwide, more often women. Sufferers may avoid anywhere that might hide spiders or shows webs, and an encounter can bring panic, crying, sweating, a racing heart and trouble breathing. All this despite most arachnids posing little danger, with exceptions such as the Sydney funnel web spider.
The evolutionary case goes like this: venomous spiders were a real hazard, so ancestors who kept their surroundings spider-free were bitten less and survived slightly better. Psychologist Arne Öhman found that fear responses to snakes and spiders could be conditioned with a single pairing, whereas neutral objects like mushrooms, flowers or even firearms and electrical outlets needed more. A 2001 study showed spiders are detected quickly among other images, and later work found reactions to pictures flashed for as little as 33 milliseconds. A 2021 study pinned the fear and disgust mainly on big fangs, a swollen abdomen and hairiness.
Critics are not convinced. There is little evidence that Pleistocene Africa held enough dangerous spider species to drive such an instinct, and an outsized fear of spiders relative to deadlier animals would have carried costs. Inherited phobias might restrict survival rather than help it. The fact that some communities happily eat spiders suggests culture plays a part, and some researchers note the fear is most common in European societies. Sensational, error-strewn media stories may add to it.
The standard treatment is systematic desensitisation, or exposure therapy, often preceded by relaxation training, and carried out with live spiders or imagined scenes. Virtual and augmented reality spiders have more recently proved effective in therapy too.
Source: Arachnophobia
