The Samaritan’s Dilemma has largely been investigated, frequently by assuming that Samaritans help recipients out of altruism. Yet, Buchanan did not make any behavioral assumption regarding the Samaritan’s motives. In this paper, we explicitly introduce this assumption in Buchanan’s original model and analyze how it changes the nature of the game. We show that altruism alone does not explain the Dilemma. A parameter that captures the disutility the Samaritan feels when helping someone who does not reciprocate her benevolence must be introduced to make sense of the different version of Buchanan’s Samaritan’s Dilemma. We also show that the Samaritan’s Dilemma is an evolutionary stable outcome, which confirms Buchanan’s intuitions. Finally, a third important point put forward in the paper is that the more altruistic are the Samaritans, the less likely it is that they will show the kind of strategic courage envisaged by Buchanan, which is one of the most important traits Samaritans should display to avoid being trapped in a Dilemma.

撒玛利亚人的困境在很大程度上得到了调查，通常是假设撒玛利亚人帮助接受者摆脱利他主义。然而，布坎南没有对撒玛利亚人的动机做出任何行为假设。在本文中，我们在布坎南的原始模型中明确引入了这一假设，并分析了它如何改变博弈的性质。我们表明只有利他主义没有解释困境。必须引入一个参数来捕捉撒玛利亚人在帮助不回报她的仁慈的人时所感受到的负效用，以理解不同版本的布坎南撒玛利亚人的困境。我们还表明，撒玛利亚人的困境是一个进化稳定的结果，这证实了布坎南的直觉。最后，论文提出的第三个重点是，越是无私的撒玛利亚人，就越不可能表现出布坎南所设想的那种战略勇气，而这正是撒玛利亚人应该表现出来的最重要的品质之一。避免陷入困境。