Rethinking Models of Subtle Dehumanization in Social Psychology

Dehumanization research has grown in recent decades, often examining contexts of intergroup attitudes and harm. Several influential models of subtle or “everyday” dehumanization have been at the forefront of these developments. One such model, infrahumanization theory, suggests that we subtly dehumanize outgroup members by seeing them as experiencing uniquely human emotions (e.g., optimism, nostalgia) to a lesser extent than ingroup members. The dual model of dehumanization suggests we subtly dehumanize human targets by denying them character traits that distinguish humans from other animals (e.g., sophisticated, civilised) or machines (e.g. interpersonally warm, openminded). However, these models have recently been critiqued, particularly for depending on the perception of prosocial aspects of humanity and overlooking antisocial aspects. Thus, we cannot disentangle dehumanization from intergroup preference – associating ingroup members with more prosocial characteristics than outgroup members. This thesis re-examines models of subtle dehumanization and associated findings considering these critiques. The hypothesised causal link between trait-based dehumanization and harm is examined in Chapter 2, demonstrating harm to be predicted by attributing undesirable traits to the target rather than denying uniquely human traits. Infrahumanization as a post hoc justification for harm is explored in Chapter 3. Rather than the pattern infrahumanization theory predicts, harmed outgroup members were seen as feeling negative emotions when harmed, regardless of emotion humanness or sense of collective responsibility. Chapter 4 re-examines infrahumanization with more robust methods than typically used, finding intergroup preference better explains apparent evidence of infrahumanization. These findings support recent critiques, with no evidence of trait or emotion-based dehumanization found across 11 highly powered studies (Ntotal = 1,748). Implications of the confounds and replicability issues for future dehumanization research are discussed. This thesis provides a strong challenge for current conceptualisations of subtle dehumanization, emphasising the importance of robust theories and replicable findings concerning urgent social issues like intergroup harm.