Unite against: A common threat invokes spontaneous decategorization between social categories

A frequent rhetoric in the political arena calls members of larger groups like nations to lay aside all dividing differences and unite in face of a common threat. In the present research we sought to test whether such a unifying effect of external threat already manifests in such basic cognitive processes as automatic categorization even for such strong schisms as the ones between black and white Americans or Israeli Jews and Arabs. In Studies 1 & 2 (N = 183/144, USA), we established the decategorization effect in the context of black and white US Americans. In Study 3, we showed the effect again in a German lab for the gender category (N = 101). In Study 4 (N = 168, Israel), we transferred the effect to the context of the Israeli-Palestinian conflict and teased apart the separate effects of intergroup threat, common goal and common threat, and category membership of participants. In summary, a “common enemy” leads to the decategorization of social groups already at an early automatic stage.