Arachnophobia (fear of spiders), ophidiophobia (fear of snakes) and acrophobia (fear of heights) afflict the majority of specific phobia sufferers, according to Weaver.
Textbooks in evolutionary psychology have proposed the hypothesis that the fear of spiders is an adaptation shaped by the mortal threat posed by their bites.
That's probably not appealing to most people, but the research team, which includes a psychologist, hopes it will become a next-generation treatment for people with arachnophobia, which is a fear of spiders.