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Why did chimpanzees evolve to be horrible monsters? I've been watching documentaries, and i've realized that no animal has terrified me as much before. Firstly, the ear splitting screams they make are frightening. Then, their mood being so unpredictable counteracts any cuteness factor. They are highly prone to anger. Chimpanzees being friendly with each other, suddenly lose it over petty issues and start ripping each other limbs off. They gang up randomly on a member of their own troop and just tear it's dick off. No one in a chimpanzee troop is ever safe. They also go on hunts where they grab smaller monkey species off trees and tear them apart alive.

Why are chimpanzees unfathomably cruel?