Epidemiology
Specific phobias have a one-year prevalence of 4.4% in the USA. The usual age of onset is childhood to adolescence. Women are twice as likely to suffer from specific phobias as men.
Evolutionary theory argues that infants or children develop specific phobias that could possible harm them, so their phobias alert them to this sense of danger. The most common co-occurring disorder for children with a specific phobia is another anxiety disorder. Although comorbidity is frequent for children with specific phobias, it tends to be lower than for other anxiety disorders. Onset is typically between 7-9 years of age. Specific phobias can occur at any age but seem to peak between 10 and 13 years of age.
Read more about this topic: Specific Phobia