>>599733I don't think anyone's ever really determined for sure, or even if it can be known for sure.
One theory I've heard that at least sounds interesting is that some young kids just aren't yet able to deal with makeup and masks. Like it takes a certain point of development before a kid can really grasp the concept of a fake face over somebody's real face. So for some kids whose brains maybe take a bit longer to reach that point, clowns freak them out on some deep, uncomprehending level, and that the memory of that fear might stick with people.
I don't know, I never really felt much about clowns one way or the other. I vaguely remember pretending to like them as a kid after I learned that my little sister was afraid of them.