Why can't we be friends? Untangling conjoined polarization in America

Abstract Party affiliation in the United States is increasingly aligned with multiple social identities. In this era of social sorting, to what extent is polarization motivated by partisan identities compared to other overlapping identities in non‐political settings? Using a conjoint survey experiment to examine the multivariate nature of affective polarization, we find that political identity outweighs all other social identities in informing citizens' attitudes and projected behaviors towards others. In addition, we find that partisanship usually outweighs ideology, but ideology matters in driving polarization; Democrats dislike Republicans more than Republicans dislike Democrats; and partisan identity has a particularly strong effect on racial and religious biases and preferences. Contrary to assumptions, cross‐cutting identities do not appear to dampen social polarization. We also find that, while out‐group animosity is stronger than in‐group sentiment in abstract attitudinal measurements, the results are mixed in interpersonal behavioral measurements, suggesting that partisan animus between citizens at the community level may be more nuanced than often suggested.