Trust can transform conflicting interests into cooperation. But how can individuals know when to trust others? Here, I develop the theory that reputation building may signal cooperative intent, or “trustworthiness.” I model a simple representation of this theory in which individuals 1) optionally invest in a reputation by performing costly helpful behavior (“signaling”); 2) optionally use others’ reputations when choosing a partner; and 3) optionally cooperate with that partner. In evolutionary simulations, high levels of reputation building, of choosing partners based on reputation, and of cooperation within partnerships emerged. Costly helping behavior evolved into an honest signal of trustworthiness when it was adaptive for cooperators, relative to defectors, to invest in the long-term benefits of a reputation for helping. I show using game theory that this occurs when cooperators gain larger marginal benefits from investing in signaling than do defectors. This happens without the usual costly signaling assumption that individuals are of two “types,” which differ in quality. Signaling of trustworthiness may help explain phenomena such as philanthropy, pro-sociality, collective action, punishment, and advertising in humans and may be particularly applicable to courtship in other animals.

中文翻译：

---

诚实表达合作意向

信任可以将利益冲突转化为合作。但是个人怎么知道何时该信任别人呢？在这里，我提出了一种理论，即信誉建立可能表明合作意向或“可信赖性”。我对该理论进行了简单的表述，其中个人1）可以选择通过执行昂贵的帮助行为（“信号发送”）来投资声誉。2）选择合作伙伴时可以选择使用他人的声誉；3）可以选择与该合作伙伴合作。在进化模拟中，出现了高水平的声誉建立，基于声誉选择合作伙伴以及合作伙伴内部的合作。相对于叛逃者而言，代价高昂的帮助行为适应了合作者（相对于叛逃者）投资于声誉长期帮助中的诚实信守信号。我用博弈论证明，当合作者比叛逃者从信号投资中获得更大的边际收益时，就会发生这种情况。在没有通常昂贵的信号假设的情况下发生这种情况，即个人属于两种“类型”，质量不同。发出可信度信号可以帮助解释诸如慈善，亲社会，集体行动，惩罚和人类广告等现象，并且可能特别适用于其他动物的求爱。