I've found reductionist social Darwinism lacks explanatory for these phenomena.
Why are you so sure that it was competition and not cooperation that ensured the strength of a tribe?
Or to put it another way, could cooperation, even cooperation with those you dislike, also lead to a materially successful tribe?
And being aware of some dynamic is totally different from being free or above its influence.
Just-so stories have that trait.
"There's a huge evolutionary advantage in calling attention to good actors (someone behaving a way which is advantegeous to the tribe), because that person will have that behaviour reinforced, and the social proof will motivate others to follow suite. This helps the group."
http://www.craigflint.com/graphics/illustrations/justsoeleph...