the only survivors in a hunter-gatherer culture were successful conservatives....(Ann Coulter,Ted Nugent types),
then the farming culture produced a need for sharing, spawning the fragile communist mindset of the leftist liberals....(Cindy Sheehan/Al Gore types)
so do the math .....which set of culture types is more likely to survive harsh circumstances
I think it may have been the other way around. In hunter-gatherer cultures, groups tend to be smaller and power less rigidly divided (or at least, not as securely held by the leader). This makes an emphasis on sharing and consensus more important. If you are related to a good chunk of the people in your tribe, don't want to constantly quarrel with them, and need cooperation to hunt big game or find the good berry patch, it makes sense to share to a large degree.
With agriculture, things are different. The surplus population created by agriculture means armies and priests can be used to enforce unequal portions of wealth and political power. It also means more anonymity in those societies thus decreasing the moral obligation to give to your fellow man but increasing the legal obligation to give to your leader. Because food is grown in fields rather than collected from wandering in nature, now lords, administrators, or perhaps the occasional lucky peasant has his OWN peice of land that he is responsible for, which formed the seeds for the idea of property rights.