社交媒体与美国公众政治极化——基于ANES社交媒体特别调查的实证研究

Social Media and Political Polarization in the United States:An Empirical Study based on the ANES Special Social Media Survey

公众政治极化作为当前美国政治最显著的特征之一,不仅降低了美国对外政策的延续性,也给世界经济与政治带来了很大的不确定性。围绕社交媒体是否加剧美国公众政治极化的争议,文章基于社会身份认同理论,提出了社交媒体通过公众身份认同的内群体偏好效应和外群体偏见效应加剧美国公众政治极化的研究假设,并利用ANES特别调查数据进行了实证检验。研究主要有四点发现:一是社交媒体显著加剧了美国公众政治极化;二是内群体偏好效应在社交媒体影响美国公众政治极化的过程中发挥了更为重要的中介机制作用;三是社交媒体对美国主流群体政治极化的影响更为显著,且更高的受教育水平不能帮助公众有效脱离社交媒体的影响;四是公众政治极化提升了美国公众的对华消极感知,对中美关系产生了外溢影响。研究回应了学界有关社交媒体如何影响政治极化的争议,弥补了既有文献对中介机制挖掘的不足,对于理解当前美国对华整体战略转型亦有一定的帮助。

As one of the most prominent features of American politics today,political polarization not only reduces the continuity of US foreign policy but also results in significant uncertainty for the global political economy.Responding to the debate over whether social media exacerbates political polarization in the United States,this article proposes a research hypothesis that social media intensifies American political polarization through in-group favoritism and out-group bias effects as articulated in social identity theory.The article goes on to conduct an empirical test of this hypothesis using the ANES special survey data.The article identities four primary findings:First,social media significantly intensifies political polarization in the United States;Second,the in-group favoritism effect plays a more significant role as an intermediatory factor as social media impacts American political polarization;Third,the influence of social media on the political polarization of the mainstream group in American politics is more significant,and higher levels of education cannot significantly help the public avoid the polarizing influence of social media;Fourth,political polarization increases negative perceptions of the American public towards China,and this has a spill-over effect on US-China relations.This study responds to the academic debate over how social media affects political polarization,and addresses gaps in the existing literature,which does not explore intermediate factors.The article is also helpful for understanding the overall shift in U.S.strategy towards China.