Understanding mechanisms behind discrimination using diffusion decision modeling

Past research has documented where discrimination occurs or tested interventions that reduce discrimination. Less is known about how discriminatory behavior emerges and the mechanisms through which successful interventions work. Two studies (N > 4500) apply the Diffusion Decision Model (DDM) to the Judgment Bias Task, a measure of discrimination. In control conditions, participants gave preferential treatment (acceptance to a hypothetical honor society) to physically attractive applicants. DDM analyses revealed participants initially favored attractive candidates and attractiveness was accumulated as evidence of being qualified. Two interventions—raising awareness of bias and asking for more deliberative judgments—reduced discrimination through separate mechanisms. Raising awareness reduced biases in drift rates while increasing deliberation raised decision thresholds. This work offers insight into how discrimination emerges and may aid efforts to develop interventions to lessen discrimination.