I recently saw a Nova type blurb titled Odyssey. It dealt with the recent evolution of homo sapiens and our distribution throughout the world.
The blurb held that sometime around one hundred thousand years ago in Eurasia five species, of hominids, including us, roamd around. Several of these were smaller in stature than us. And, Neanderthal was largger in stature. Yet we survived and they dies out.
Now before you start chanting Only The Strong Survive, be it known that we survived becaused we exceded all in cunning, craft, and skill but not strength. I have another lecture planned on the evils of the misrepresentations of Darin's theory, eugenics, and German National Socialism.
Now, I hold that we have a distinct memory hard wired into our brain tissue of the other hominid species. These memories show up in the persistence of fairies, trolls, and Trumps in our folk tales.
But let us consider the trolls and other fearsome spectors. We would have undoubtedly had to compete with the other species for resources such as caves, food, and votes. Certainly, that competition could not always have gone smoothly. It surely must have put some of us in peril.
QED: From thence comes the fear of clowns. What is a clown anyway. A creature whose skin is not like ours. Whose hair bears no resemblance to ours. And, whose behaviour, especially in front of a television camera / political debate shows no sign civilization and is punctuated with grunts and spitting.