Clown-like characters have been a part of popular culture for centuries. Yet some people have always found them creepy, and about 2 percent of the population experiences coulrophobia, or a fear of clowns. The reaction may be due not just to news reports of crimes by people in clown masks or makeup, but to the ambiguity that even harmless clowns present. With painted-on, unchanging expressions, clowns’ emotions can be hard to read and their intentions may seem unpredictable. The phenomenon known as deindividuation, leads to further unease: Since the identities of the men or women behind the makeup are hidden, others may become fearful of what they might do under cover of anonymity.