Kind of fits with all the face-eating and cannibalism among humans in the US.
We live in interesting times, perhaps a multi century peak of zeal and emotion, barreling into a brick wall of reality.
Simple theory, I guess I could write a 300 page book on it. Evolution found that by instigating big social mood waves/fractals, that populations of mammals would occasionally "go off" resulting in wars and fights and knocking the mammals out of their established patterns since getting locked into a pattern in a changing world was an evolutionary non-advantage.
Also, the corollary is that insanity, as demonstrated by the psychopathy of those who rise to the top....lying to all around them, while stroking everyone's ego and usually not offending anyone so bad that they "lose them"....also that insanity is an evolutionary advantage. It is well rooted in 80% of human activity, just look how people make decisions on a daily basis....very little to do with practicality, much more to do with advancing and protecting the ego.
JOHANNESBURG (AP) — Chimpanzees at a sanctuary for the animals in eastern South Africa pulled an American researcher who was leading a tour into their enclosure, bit him severely and dragged him nearly half a mile (kilometer).
The man was giving a lecture at the Jane Goodall Institute Chimpanzee Eden on Thursday when two chimpanzees grabbed his feet and pulled him under a fence into their enclosure, said Jeffrey Wicks of the Netcare911 emergency services company.