The humanity inventory: Developing and validating an individual difference measure of dehumanization propensity

Dehumanization is often explored in the context of inhumane acts of intergroup and interpersonal violence, and is considered a precursor to extreme atrocities. However, research suggests that we may all engage dehumanized perceptions, at least occasionally, if the social context or goals encourage dehumanization. This implies an individual difference nature of dehumanization propensity. Across four online studies (cross-sectional Studies 1, 3, 4, and longitudinal Study 2), we develop and validate the Humanity Inventory (HumIn), a self-report measure of individual differences in the propensity to engage dehumanization. Study 1 (N = 86) entailed item selection. Study 2 (N = 235) examined the validity of the scale and investigated its test–retest reliability. Study 3 (N = 259) compared the HumIn with pre-existing scales measuring related constructs. Study 4 (N = 98) examined the scale's performance in a situational example of dehumanization. Across all studies, the HumIn performs admirably, showing excellent reliability and validity. This novel instrument and broader conceptualization of dehumanization propensity should allow researchers to tackle questions related to dehumanization from a novel perspective, and will aid future research by providing a tool for assessment.