DescriptionIndiscriminate aggression includes diverse instances of aggression or violence in which victims are haphazardly targeted, ranging in severity from lethal violence to relatively low levels of aggression. High-profile perpetrators of indiscriminately aggressive acts have endorsed beliefs dehumanizing others, and it is likely that dehumanization beliefs may be associated with indiscriminate aggression at all levels of severity. It is posited that this aggression-supporting belief is uniquely associated with indiscriminate aggression. The current investigation encompasses 1) the development and validation of an original measure of dehumanization beliefs, 2) an examination of the nature of dehumanization beliefs, 3) the development and validation of a measure of indiscriminately aggressive behavior and 4) an examination of the link between dehumanization beliefs and indiscriminate aggression. Preliminary study 1 examined the role of emotional state in the perception of violent images using a mood induction paradigm. Results of preliminary study 1 indicate that angry individuals perceive videos of violent acts as more exciting and entertaining as compared to individuals who are not angry. Preliminary study 2 examined the correlates of identification with an indiscriminate aggressor using a questionnaire. Results of preliminary study 2 indicate that identification with the Virginia Tech shooter was associated with aggressive behaviors and beliefs. Preliminary study 3 examined the reliability and validity of a new measure of dehumanization beliefs, the Dehumanization Beliefs Scale (DBS). Results of preliminary study 3 indicate that the DBS is a reliable and valid measure of dehumanization beliefs. Dissertation study 1 examined the role of emotional state in the relation between dehumanization beliefs and rates of indiscriminately aggressive behavior using a mood induction paradigm. Results of dissertation study 1 indicate that both anger and anxiety influence the relationship between dehumanization beliefs and indiscriminately aggressive behavior. Dissertation study 2 examined the relation between dehumanization beliefs and rates of indiscriminately aggressive behavior. Results of dissertation study 2 indicate that the degree to which an individual endorses dehumanization beliefs is related to rates of indiscriminately aggressive behavior. This work has implications for the prediction and prevention of indiscriminate aggression and violence.