system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is fear of clowns such a common phobia?
gpt
Clown's costumes distort and exaggerate their features for humorous effect. However, we naturally find feature distortions as worrying or frightening because deformities are indicative of disease. There's also the uncanny valley effect, in which we find things that are *almost* human in appearance far more disturbing than things that are obviously fake, probably for the same reason. Children are less easily able to tell that clowns are fake and are thus more likely to fear them, a fear that can carry over to adulthood.