When I was studying for my Ph.D, psychologists were just beginning to suggest that perhaps the species-centric view that only humans were capable of higher mental activities like problem-solving, loving, and social interaction was wrong.
With time, research has made it increasingly difficult to maintain that these activities are uniquely human. Evidence that animals not only solve problems, but often have a sense of humor, and grieve when they lose a child or friend is not extensive.
The practice of killing chimpanzees for bushmeat is not uncommon in the few places where this threatened relative of ours still survives. But I think seeing a whole community of chimpanzees mourning for the loss of one of their friends would make it feel like cannibalism.
