Doctoral Dissertation Research in Political Science: Partisan and Ideological Sorting in the United States

几十年来，政治学家一直在争论美国是否正在发生政治两极分化。然而，对于两极分化是什么，人们没有统一的定义，也没有就可能导致两极分化的原因达成一致。该项目旨在改变这场辩论的措辞，既明确和一致地界定两极分化的概念，又查明两极分化存在的原因和过去五十年来两极分化加剧的原因。该项目将政治两极分化定义为公民从中间派、温和的政治信仰或行为转向更极端的信仰或行为的过程。该项目表明，美国公民在问题立场或行为上可能会两极分化，这两件事不一定要同时发生。因此，尽管问题立场两极分化的程度可能很低，但行为两极分化--其特征是激进主义、不容忍和愤怒程度增加--可以而且今天不可否认地在上升。过去几十年来，政党和意识形态认同的逐渐一致加剧了这种行为两极分化。美国公民在政治上更加活跃、不宽容和愤怒，因为政党身份已经与其他政治身份(意识形态、宗教和种族)一致。其他研究表明，当多种身份一致时，公民对其他人的容忍度就会降低。该项目进一步认为，当政治身份一致时，政党身份就会得到加强。研究还表明，身份认同感更强的人更不宽容，会代表他们所属的群体采取更多行动。该项目认为，这种心理反应本质上是情绪化的，与对问题的慎重考虑无关。如果这一论点成立，那么游击队有不文明行为的深层心理动机，而且自20世纪60年代以来，这些动机的强度有所增加。这项研究通过从具有全国代表性的美国成年人样本中收集数据来检验其论点。具体地说，一项基于网络的调查将被用来评估一系列政治认同(党派、意识形态、宗教、种族和基于问题的)之间的关系，以及这些身份对政治行为的影响。此外，调查还将被用来检验问题立场极端对政治行为的作用。如果这里的推理是正确的，那么与政治认同力量相比，问题立场极端在激发政治激进主义、不容忍和愤怒方面发挥的作用应该更小。此外，最重要的是，政治认同高度一致的个人应该比那些政治认同不一致的人更积极、更不宽容、更愤怒。该项目将在两个领域提供至关重要的见解。首先，它将通过引入准确的定义和确定起作用的因果机制，推动一场长期存在的学术辩论。其次，该项目将揭示两极分化和不宽容的党派辩论的心理动机。

For decades, political scientists have argued about whether political polarization is occurring in the United States. Yet there has been no common definition of what polarization is and no agreement as to what might cause it. This project aims to change the terms of this debate, both by defining the concept of polarization clearly and consistently and by identifying the reasons for the existence of polarization and for its increase over the last fifty years. The project defines political polarization as a process by which citizens move from centrist, moderate political beliefs or behavior to more extreme beliefs or behavior. The project suggests that US citizens can be polarized over issue positions or in their behavior, and that these two things need not happen at the same time. Hence, while levels of issue position polarization may be low, behavioral polarization--characterized by increased levels of activism, intolerance and anger--can be and is today undeniably on the rise. This increased behavioral polarization has been fueled by the gradual alignment of party and ideological identities over the last few decades. US citizens are more politically active, intolerant and angry because party identities have come into alignment with other political identities (ideology, religion, and race). Other studies have shown that when multiple identities come into alignment, citizens become less tolerant of others. This project further contends that when political identities come into alignment, party identities are strengthened. Studies have also shown that those with stronger identities are more intolerant, and take more actions on behalf of the group to which they belong. This project argues that this psychological reaction is emotional in nature and is unrelated to measured considerations of issues. If this argument holds, then partisans have deep psychological motivations to be uncivil, and the strength of these motivations has increased since the 1960s. The research examines its arguments by collecting data from a nationally representative sample of adult Americans. Specifically, a web-based survey will be used to assess the relationships among an array of political identities (partisan, ideological, religious, racial, and issue-based), and the effect of these identities on political behavior. In addition, the survey will be used to examine the role of issue position extremity on political behavior. If the reasoning here is right, issue position extremity should play a smaller role in motivating political activism, intolerance, and anger than does political identity strength. Furthermore, and most importantly, individuals with high levels of alignment among their political identities should be more active, intolerant and angry than those whose political identities are not in alignment. This project will provide crucial insight in two arenas. First, it will move forward a long-standing academic debate, by introducing a precise definition and identifying causal mechanisms at work. Second, the project will shed light on the psychological motivations of polarized and intolerant partisan debate.