I was reading this thing, I don't know if it is original or not but i was wondering...it talk about how there are things that humans are instinctually afraid of things (thunder-could be a stampede, darkness-unseen predators, heights-lethal slip up, etc)

Well it asked what in our past made us inherently afraid of thinks with dark, sunken eyes, long faces, sharp teeth and pale skin.

what what was it?