Back when I was in high-school, our "extended learning" course was given a "real world" demonstration of Randian versus Liberal ideology via an old party game. If everyone in the group is willing to accept a moderate reward, then everyone can simply have that moderate reward. If any one person gets greedy while everyone else is moderate, they can have a much greater reward and reduce the share of the moderates, but that much greater reward needs to be shared among the greedy people. If too many people vote greedily there is no reward whatsoever (for anyone).