We did come to that fork when we left the trees and that's why our brain grew so rapidly, to allow communication and cooperation. We were not efficient enough to survive without a cooperative strategy. Then we hit another fork 70,000 years ago when our "parietal lobe developed some" or you could say our brain re-organized. We became efficient enough that we could go back to the more common blindly competitive strategy of nature, red of tooth and claw. (You can find both of those instincts within yourself and I may have a more detailed essay on Medium about it.) That older instinct almost killed a us a few times and everyone hated it, so about the time of Rome, not only were there philosophies developed to deal with war, Buddhism and Stoicism, but there was a philosophy developed to prevent it. Because everyone was so tired of war, there was some obscure philosopher that actually got some traction with the strategy. Heck, people even elevated him to Godhood for it. I think his name was Jesus or something.