Who would you vote off the island: the selfish ass or the generous spirit? The selfish ass, right? Rational.
WSU scientist Craig Parks along with Asako Stone set out to figure out exactly how much loutish behavior a group will tolerate before throwing the selfish out. What they discovered is far more interesting:
...we also observed a completely unanticipated and, we argue, more interesting result: Those who give much to the group effort yet take little of its subsequent reward are not applauded but rather targeted for expulsion. The effect was replicated across three subsequent studies. Two of these studies ruled out some rather mundane explanations for the finding (lack of understanding of the task by the benevolent other, the other behaving unpredictably), and a third suggested that people are motivated to expel the benevolent other either for self-image reasons or because the other is not adhering to common rules of behavior. In this article, we report on this series of studies.
What the hell. The authors go on to attempt to explain why:
These data, then, provide potential explanations for why people want to remove a benevolent individual from the group. In some cases, the individual makes others feel they look bad in comparison, and, in other cases, the person is seen as violating rules of social interaction for mixed-motive situations. As we solicited these explanations after the expulsion preference had been stated, it is certainly possible that they represent not motivations for removing a benevolent other but rather rationalizations for why subjects want the benevolent person removed.
If you were looking for an empiric basis for the "Keep the government's hands off my Medicare" red state, federal subsidy dependent elderly white teapartier, this is a good place to start.