Several years ago I viisted the Grand Canyon- My GF and I were standing close to a park ranger at the top of a canyon- I saw a raven flying and pointed it out to my GF- the park ranger added this interesting fact about Ravens.
Apparently the ravens will start playing with wolf pups as soon as they start making 'public' appearances outside of the den- the adult wolves are OK with the ravens playing with their pups because they too played with the ravens when they were pups- this is why ravens are the only animals that the wolves will share their kills with- brilliant and forward thinking I'd say.
A key to cooperation is interaction, that association breeds identification and valuation which affects bonds and how to treat them. This applies throughout the animal kingdom, including humans. If people interacted more with animals, they would see the more as others, and less as things to do with as we please, as if we can actually own another or kill them just because we want to eat them.