In his book "The Selfish Gene", Richard Dawkins says that retaliator emerges as an evolutionary stable strategy. But I think dove is also a kind of retaliator and so if dove increases, the hawks and ...
It is known from theoretician in the field of kin selection that kin selection (inclusive fitness theory) and group selection are actually two sides of the same coin. In other words, these two ...
I think the best explanation might come from evolutionary game theory. But, an another viewpoint may be equally important.