There is a lot of talk about altruism upthread. But altruism is not a single concept. The dictionary definitions are kind of loose - basically "putting the interests of other people first". But that can be as simple as how I take care of the old lady next door. I cut her grass. I make sure she gets a few good meals a week. I buy her groceries. I take her to the doctor. She asked "Why are you being so nice to me?" I have two answers, "First because it's right to help your less fortunate neighbors. Second, some day I may need help and I hope, through example, that some one else will do the same for me". I have her interest at heart. I help her. I do it on my on volition, indeed if I were required to help, I would decline and fight it. I, at least potentially, get something in return. This is hardly non-Darwinian.
The opposite extreme to altruism is "Don't kill him, kill me instead" - i.e. a sacrifice of the ultimate type. While I would fight for a cause and maybe die, I would not not give what is most valuable to me for nothing. This is also hardly not-Darwinian.
I guess I don't see why being a good neighbor has anything to do with Darwin. Assuming evolution is cold and inhuman assumes facts not in evidence. The biological survival and evolution of the species will continue in spite of societal pressures, not because of them, even though they are inextricably intermixed.