We often treat social media as a lens onto society. How might that lens be distorting the actual popularity of political and social viewpoints? In this paper, we examine the difference between the viewpoints publicly posted in a community and the privately surveyed viewpoints of community members, contributing a measurement of a theory called the "spiral of silence." This theory observes that people are less likely to voice their opinion when they believe they are in the minority--leading to a spiral where minority opinions are less likely to be shared, so they appear even further in the minority, and become even less likely to be shared. We surveyed active members of politically oriented Reddit communities to gauge their willingness to post on contentious topics, yielding 627 responses from 108 participants about 11 topics and 33 subreddits. We find that 72.6% of participants who perceive themselves in the minority remain silent, and are only half as likely to post their viewpoint compared to those who believe their opinion is in the majority. Communities perceived as being more inclusive reduce the magnitude of this effect. These results emphasize how far out of step the opinions we see online may be with the population they purport to represent.

翻译：我们常将社交媒体视为观察社会的透镜。这一透镜如何扭曲政治与社会观点的实际流行度？本文通过考察社区公开表达的观点与社区成员私下调查观点之间的差异，对"沉默螺旋"理论进行了量化测量。该理论指出，当人们认为自身属于少数派时，其表达观点的意愿会降低——这种机制会形成螺旋效应：少数派观点因较少被表达而显得更为边缘化，进而导致其表达概率进一步降低。本研究通过对政治导向的Reddit社区活跃成员进行问卷调查，评估他们在争议性话题中的发帖意愿，共收集108名参与者关于11个话题和33个子版块的627份有效回复。研究发现：72.6%自认处于少数派的参与者保持沉默，其发表观点的可能性仅为自认多数派参与者的一半。而被认为更具包容性的社区能显著减弱这种效应。这些结果凸显了网络可见观点与其所代表群体真实意见之间的巨大偏差。