I think about this a lot does that explain intra species killings? cave person A see sabertooth cave person A dead cave person B also see sabertooth cave person B dead cave person c gotta kill sabertooth before cave person c dead. cave person eat sabertooth like sabertooth eat cave person A & B I understand but not cave person A kill cave person B cause caveperson different / new its not like humans eat humans haha unless you're a wendigo ofc
Two possible reasons why humans don't eat humans (except when we do):
We're hardwired to have empathy for our own kind, e.g. the "selfish gene" theory, stronger for kin than for strangers but nonetheless strong enough to create an almost universal taboo against eating people. Note however that many other animals do seem to be wired to eat some of their own children: https://en.wikipedia.org/wiki/Filial_cannibalism
"The most dangerous game." People are very resourceful, and furthermore have friends and family who hold grudges. Eating people is a bad strategy because people who make a habit of it tend to get killed for it sooner or later. Hunting nearly anything else is safer than hunting other humans.
Eating one's own species is a fairly complex topic, and there are many local optimas. For a detailed read on this topic, see "The Red Queen" by Ridley.
