I don't think that's the tacit theory of ethics around here.

Genes may be selfish, but primates survived better who had other related primates looking out for them, or who showed that they were caring. It could well be that some simple mutations led to primates that showed they were caring because they actually were caring. (Edit: It seems to me that this must be the case for at least part of our value system. )

This is relevant:

http://lesswrong.com/lw/uu/why_does_power_corrupt/

but the benefits to the genes can just as easily come from more subtle situational differences, and assistance by related others, rather than a major status change and change in attitudes.