While there is a plethora of experimental studies on the effects of preplay communication on economic behavior, little is known about the impact of simple cues, such as smiling, on pro‐sociality. This article presents a comprehensive analysis exploring how the presence of a smiling opportunity affects pro‐social behavior as measured by a one‐shot linear public goods game. Our design varies (i) whether smiling is costly or costless and (ii) whether one or both members in a group are given the opportunity to smile. To test for the robustness of our results, we consider two versions of smiling cues: (i) a smiling label and (ii) a smiling face (emoji). Our findings indicate that introducing a cost for smiling has detrimental behavioral consequences regardless of the cue. Specifically, when smiling is costly, only a small minority of subjects are willing to smile as opposed to when smiling is costless. As a result, subjects contribute significantly less. These results remain the same regardless of the type of smiling cue that subjects can send. Overall, our findings provide new evidence that simple cues such as smiles embody information that influences pro‐social behavior in social interactions.

中文翻译：

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微笑线索对社会合作的影响

尽管有很多关于事前沟通对经济行为影响的实验研究，但对诸如笑容之类的简单提示对亲社会性的影响知之甚少。本文提供了全面的分析，探讨了微笑机会的存在如何影响一次性社交线性公益游戏所衡量的亲社会行为。我们的设计各不相同（i）微笑是昂贵的还是无成本的，以及（ii）小组中的一个或两个成员是否都有微笑的机会。为了测试结果的稳健性，我们考虑了两种形式的微笑提示：（i）微笑标签和（ii）微笑面孔（表情符号）。我们的发现表明，不管提示如何，引入微笑费用都会带来有害的行为后果。具体来说，当微笑的代价很高时，与之相比，只有一小部分对象愿意微笑，而微笑是无价的。结果，受试者的贡献显着减少。无论对象可以发送的微笑提示的类型如何，这些结果都将保持不变。总体而言，我们的发现提供了新的证据，表明诸如微笑之类的简单线索体现了影响社交互动中亲社会行为的信息。