I can't say much about the monkey tribe example that Eliezer quoted -- for example I don't know if it is true or if it implies anything about human evolution -- but I have found that people are remarkably adaptable with cultural conditioning.

I would also like to point out that there is a difference between people doing what you tell them and people only working if you explicitly tell them to; it is possible for people to be receptive to commands and yet be self directed. My current work environment is full of examples.

If true, that still tells us very little about whether the evolutionary approach could be overridden by a cultural one.