We consider agents in a social network competing to be selected as partners in collaborative, mutually beneficial activities. We study this through a model in which an agent i can initiate a limited number k_i>0 of games and selects the ideal partners from its one-hop neighborhood. On the flip side it can accept as many games offered from its neighbors. Each game signifies a productive joint economic activity, and players attempt to maximize their individual utilities. Unsurprisingly, more trustworthy agents are more desirable as partners. Trustworthiness is measured by the game theoretic concept of Limited-Trust, which quantifies the maximum cost an agent is willing to incur in order to improve the net utility of all agents. Agents learn about their neighbors' trustworthiness through interactions and their behaviors evolve in response. Empirical trials performed on realistic social networks show that when given the option, many agents become highly trustworthy; most or all become highly trustworthy when knowledge of their neighbors' trustworthiness is based on past interactions rather than known a priori. This trustworthiness is not the result of altruism, instead agents are intrinsically motivated to become trustworthy partners by competition. Two insights are presented: first, trustworthy behavior drives an increase in the utility of all agents, where maintaining a relatively modest level of trustworthiness may easily improve net utility by as much as 14.5%. If only one agent exhibits modest trust among self-centered ones, it can increase its average utility by up to 25% in certain cases! Second, and counter-intuitively, when partnership opportunities are abundant agents become less trustworthy.

翻译：我们考虑社交网络中的代理为成为协作、互利活动中的合作伙伴而竞争的情景。通过一个模型进行研究：代理i可发起有限数量k_i>0的博弈，并从其一跳邻居中选择理想合作伙伴；同时，它可接受来自邻居发起的任意数量的博弈。每个博弈代表一项生产性的联合经济活动，参与者试图最大化其个体效用。不出所料，更值得信任的代理作为合作伙伴更具吸引力。信任度通过博弈论概念“有限信任”衡量，该概念量化了代理为提升所有代理的净效用而愿意承担的最大成本。代理通过互动了解邻居的信任度，其行为随之演化。在真实社交网络上进行的实证试验表明：当拥有选择权时，许多代理表现出高度可信；当邻居信任度的信息基于过往互动而非先验已知时，大多数或全部代理会变得高度可信。这种信任并非源于利他主义，而是代理因竞争而内在地被激励成为值得信任的伙伴。研究提出两点见解：第一，可信行为会提升所有代理的效用，保持适度信任水平即可轻松使净效用提升高达14.5%。若仅有一名代理在自私群体中展现适度可信，其平均效用在某些情况下可提升25%！第二，反直觉的是，当合作机会充足时，代理的信任度反而降低。