Rand David G, Armao Joseph J, Nakamaru Mayuko, Ohtsuki Hisashi
Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA.
J Theor Biol. 2010 Aug 21;265(4):624-32. doi: 10.1016/j.jtbi.2010.06.010. Epub 2010 Jun 9.
The evolution of cooperation is one of the great puzzles in evolutionary biology. Punishment has been suggested as one solution to this problem. Here punishment is generally defined as incurring a cost to inflict harm on a wrong-doer. In the presence of punishers, cooperators can gain higher payoffs than non-cooperators. Therefore cooperation may evolve as long as punishment is prevalent in the population. Theoretical models have revealed that spatial structure can favor the co-evolution of punishment and cooperation, by allowing individuals to only play and compete with those in their immediate neighborhood. However, those models have usually assumed that punishment is always targeted at non-cooperators. In light of recent empirical evidence of punishment targeted at cooperators, we relax this assumption and study the effect of so-called 'anti-social punishment'. We find that evolution can favor anti-social punishment, and that when anti-social punishment is possible costly punishment no longer promotes cooperation. As there is no reason to assume that cooperators cannot be the target of punishment during evolution, our results demonstrate serious restrictions on the ability of costly punishment to allow the evolution of cooperation in spatially structured populations. Our results also help to make sense of the empirical observation that defectors will sometimes pay to punish cooperators.
合作的进化是进化生物学中的重大谜题之一。惩罚被认为是解决这一问题的一种方法。这里惩罚通常被定义为给作恶者造成伤害而自己要付出代价。在有惩罚者存在的情况下，合作者比非合作者能获得更高的收益。因此，只要惩罚在群体中普遍存在，合作就可能进化。理论模型表明，空间结构可以通过允许个体只与紧邻区域的个体互动和竞争，从而有利于惩罚与合作的共同进化。然而，这些模型通常假定惩罚总是针对非合作者。鉴于最近有关针对合作者的惩罚的实证证据，我们放宽这一假定，研究所谓“反社会惩罚”的影响。我们发现进化可能有利于反社会惩罚，而且当反社会惩罚成为可能时，代价高昂的惩罚不再促进合作。由于没有理由假定在进化过程中合作者不会成为惩罚的目标，我们的结果表明代价高昂的惩罚在空间结构群体中促进合作进化的能力受到严重限制。我们的结果也有助于理解背叛者有时会付出代价去惩罚合作者这一实证观察结果。
