Solidarity Between People of Color: Two Blockage Experiments Suggest It Is Causal and Resistant to a Divisive Threat

Abstract Mounting research finds that shared discrimination boosts solidarity between people of color (PoC), with downstream increases in support for pro-outgroup policies. However, these experiments measure the proposed mediator (solidarity), rather than manipulate it, which raises reasonable doubts about its causal impact. We report two pre-registered experiments (N = 2,692) that reassess solidarity’s causal influence by “blocking” its downstream effects. We conducted these studies with Black adults – the prototypical person of color who define this mega-group’s norms and values. Both studies focus on Black-Latino relations and reveal that manipulating shared discrimination between these groups heartily boosts Black solidarity with PoC ( d ∼.40). Critically, after solidarity’s activation, manipulating differences in the bases of discrimination against Black and Latino people (i.e., slavery versus immigration) modestly reduces its downstream effect on Black support for pro-Latino policies. A pre-registered internal meta-analysis finds this “blockage” effect is modest but statistically reliable ( d ∼.10), leading us to conclude that solidarity’s mediating influence is likely causal and resistant to this divisive threat. We discuss our results’ implications for inter-minority politics.