Sure there is. It's a more effective evolutionary strategy. Animals that cooperate and socialize tend to do better than animals that don't.
Are you saying cooperation is a non-zero-sum game? :-D
I'm noticing that a lot of people on FR don't even understand what the Golden Rule is. That would include you.
When wolves hunt in a pack, they are not practicing the Golden Rule, nor altruism. If they were to continue bringing food to a toothless wolf that could no longer hunt, nor reproduce at the detriment of their own chances for survival, then they would be practicing altruism.