In the current political climate in the United States and other Western countries, there is widespread belief that that people are polarized on the left-right political spectrum and act in partisan ways. Evidence for this belief is often based on actions and statements by political leaders, both elected and not, as well as journalistic accounts of rallies and protests. However, little is known about how much individuals actually vary on their openness to communicate with people who have different political views. What proportion of citizens operate in a bubble and how many are seeking to understand complicated political, social and economic positions of others? In this research project, we aim to develop a measure to assesses openness to political pluralism — openness to different political views — that can be used to understand individual and population variation. Openness to political pluralism is multi-determined. Specifically, we think that there exist four key dimensions that influence political pluralism: absence of rigidity/dogmatism, tolerance, motivation, and emotional reaction. First, those who are rigid or dogmatic are unlikely to be interested in different political views. Second, those who are tolerant of other positions are in a position to learn from others. Third, an explicit interest in the other positions makes communication more likely. Last, if people find it distressing to have conversations with those with different political standpoints, they are less likely to engage in these political dialogues. We have developed 25 items that reflect these facets of political pluralism. These items originally come from doctoral student exercises in an applied psychometric class (Fall, 2017) at New York University. We will collect new data and conduct factor analysis of these 25 items to verify the structure of our proposed political pluralism measure (POL; pluralism openness long). We will then establish how political pluralism is associated with left-right political orientation and openness personality from the big five personality tradition. After that, we will examine whether political pluralism is associated with openness behavior, such as news consumption and information seeking preference, and with having a social network that has homogeneous political views (see preregistration plan for our predictions). We will also follow up with a subsample of participants to estimate test-retest reliability. Lastly, to enable the measure to be used in political surveys, we will develop a brief version of the scale (POS; pluralism openness short). In response to feedback from journal review submission, we collected another replication data set using Qualtrics-Panel to obtain representative US data during September 2020. We maintained our original predictions about the fit of the 25 item scale, and its relation to other measures of openness and left-right orientation.