Department of Psychology, University of Guelph, 50 Stone Rd. E., Guelph, ON Canada, N1G 2W1.
Proc Biol Sci. 2020 Jun 24;287(1929):20200819. doi: 10.1098/rspb.2020.0819. Epub 2020 Jun 17.
Why do we care so much for friends, even making sacrifices for them they cannot repay or never know about? When organisms engage in reciprocity, they have a stake in their partner's survival and wellbeing so the reciprocal relationship can persist. This stake (aka fitness interdependence) makes organisms willing to help beyond the existing reciprocal arrangement (e.g. anonymously). I demonstrate this with two mathematical models in which organisms play a prisoner's dilemma, and where helping keeps their partner alive and well. Both models shows that reciprocity creates a stake in partners' welfare: those who help a cooperative partner--even when anonymous--do better than those who do not, because they keep that cooperative partner in good enough condition to continue the reciprocal relationship. 'Machiavellian' cooperators, who defect when anonymous, do worse because their partners become incapacitated. This work highlights the fact that reciprocity and stake are not separate evolutionary processes, but are inherently linked.
为什么我们如此关心朋友，甚至愿意为他们做出牺牲，即使他们无法回报或永远不知道？当生物体进行互惠时，它们在伴侣的生存和幸福方面有利益关系，因此互惠关系可以持续下去。这种利益（又名适应度相互依存）使生物体愿意超越现有互惠安排进行帮助（例如匿名帮助）。我通过两个数学模型来证明这一点，在这些模型中，生物体玩囚徒困境游戏，帮助可以使它们的伙伴保持生存和良好状态。这两个模型都表明，互惠创造了对伙伴福利的利益：那些帮助合作伙伴的人——即使是匿名帮助——会比不帮助的人做得更好，因为他们使那个合作伙伴保持良好状态，以继续互惠关系。当匿名时，“马基雅维利主义”的合作者会背叛，因为他们的伙伴变得无能为力，因此他们的处境会更糟。这项工作强调了一个事实，即互惠和利益不是分开的进化过程，而是内在地联系在一起的。
