is just plain wrong. The human animal is weak, slow, nearly deaf and blind, and our olfactory skills laughable, IOW we are singularly unsuited to survival. Nature's indifference forced us to evolve into the communicative, highly social animals we are today. The
only way we've survived is to band together and form communities, working for the common good.
If you withhold your extra food from my starving grandmother, I'm not rushing over to help you kill the bear that decided you would provide both a nice shelter and a tasty snack.
There is not such thing in science as 'social Darwinism', nor any model of such, this is a nothing but a catch-phrase used to divert or squelch discussion of social issues. From
http://en.wikipedia.org/wiki/Social_Darwinism">the Wiki article; "Social Darwinism is a pejorative term used to attack ideologies or ideas allegedly misusing concepts in biology in social sciences to promote a wide range of social concepts..."
How far to take it? This question is pejorative in it's construct, there are only three social states, progress, regress, or stagnation.
Perhaps I have misunderstood what you are really asking, but it seems that the question is loaded to make conclusion impossible.