>It's seen in a wide range of animals, including our closest primate cousins, chimpanzees
>If it's natural, i.e. observed in nature, then it's allright
That stance is as retarded as "if it's unnatural, then it's allright". Chimpanzees also engage in cannibalism, kill their infants and have bloody wars. Should we accept these things for humans as well, because some hairy monkeys in the jungles have them?
>Something that is so widespread across the animal kingdom certainly can't be prevented by rules or restrictions in our society.
It must. Unlike animals, we have societies, we have rules, we have restrictions. Because unlike animals, we have consciousness and conscience. All they have are their instincts. We must strive to be better then animals, not to regress to their state.