The Ascent of Man: Theoretical and Empirical Evidence for Blatant Dehumanization

Dehumanization is a central concept in the study of intergroup relations. Yet although theoretical and methodological advances in subtle, everyday dehumanization have progressed rapidly, blatant dehumanization remains understudied. The present research attempts to refocus theoretical and empirical attention on blatant dehumanization, examining when and why it provides explanatory power beyond subtle dehumanization. To accomplish this, we introduce and validate a blatant measure of dehumanization based on the popular depiction of evolutionary progress in the Ascent of Man. We compare blatant dehumanization to established conceptualizations of subtle and implicit dehumanization, including infrahumanization, perceptions of human nature and human uniqueness, and implicit associations between ingroup-outgroup and human-animal concepts. Across 7 studies conducted in 3 countries, we demonstrate that blatant dehumanization is (a) more strongly associated with individual differences in support for hierarchy than subtle or implicit dehumanization, (b) uniquely predictive of numerous consequential attitudes and behaviors toward multiple outgroup targets, (c) predictive above prejudice, and (d) reliable over time. Finally, we show that blatant-but not subtle-dehumanization spikes immediately after incidents of real intergroup violence and strongly predicts support for aggressive actions like torture and retaliatory violence (after the Boston Marathon bombings and Woolwich attacks in England). This research extends theory on the role of dehumanization in intergroup relations and intergroup conflict and provides an intuitive, validated empirical tool to reliably measure blatant dehumanization.