随着空气质量的持续下降，雾霾问题受到热议。但是，尽管前人揭示了雾霾对健康、情绪方面的影响，少有研究探索了雾霾对道德的影响，其中的机制也仍需进一步探究。雾霾天能见度差，且人们多戴口罩，匿名性增强。本研究试图揭示雾霾对不道德行为的影响，并探究匿名性在其中的作用。研究1a通过大数据表明空气质量和学术作弊程度有关；研究1b进一步通过实验表明，启动对雾霾或雾的感知会导致更多的不道德行为和更低的道德标准；研究2证实了匿名性在雾霾对不道德行为的影响中所起的中介作用；研究3a发现，佩戴防霾口罩会引发更多的不道德行为；研究3b揭示了口罩的调节作用，即佩戴口罩会增加雾霾的不道德影响，而雾霾引发的焦虑情绪并不起中介作用。因此，本研究表明匿名性是雾霾引发更多不道德行为的机制。

Air pollution has become a heated topic across the globe, featured by continuously-deteriorating air quality. Despite the fact that numerous research has confirmed health and emotional aspects of the adverse effects of air pollution, little has been explored about the ethical costs of air pollution. Moreover, the underlying mechanism by which air pollution and unethical behavior are related has not been well established. The goal of the present study is to elucidate the impact of air pollution on morality, with the specific goal of examining the possible underlying role of anonymity. Air pollution and haze could induce dark smog that undermines visibility, promoting anonymity. What’s more, wearing a mask on the face, which intensified perceived anonymity, could boost the ethical effects of haze. With big data and four experiments, the present research indicated that experiencing haze gives rise to unethical behaviors and anonymity might be the underlying mechanism. At a general level, air quality was positively correlated with the search volume for academic cheating (study 1a). When analyzing from an individual level, participants psychologically experiencing haze and fog tended to cheat more and have a higher moral acceptance for immoral behaviors (study 1b). The effect of masking on unethical behaviors was mediated by the perceived anonymity produced by masking (study 2). More impressively, wearing a respiratory mask, which is specially made for preventing haze, would result in a higher level of unethical behaviors (study 3a). Furthermore, masking, a way to enhance anonymity, would amplify the ethical effects of haze, but anxiety caused by haze is not the underlying association between haze and unethical behaviors (study 3b). Overall, perceived anonymity is an imperative psychological process underlying the unethical effects of haze.