Challenging the Mechanism for the Implicit Association Test

Implicit biases are stereotypes and attitudes that influence decisions and actions, contributing to discrimination and societal inequities. The Implicit Association Test (IAT) is the most widely used tool for measuring implicit bias, assessing response time in sorting stimuli into labeled categories. Most interpretations assume that IAT performance (D-scores) reflects conflicting associative memories or decision ease. We challenged this assumption by decomposing D-scores into additional cognitive processes that may influence results, particularly response caution—the tendency to trade speed for accuracy. Using Racing Diffusion Models across 39 topics (N = 115,601), we found that response caution explained significantly more variance in D-scores beyond decision ease. Response caution also best predicted explicitly reported biases. These findings challenge the traditional interpretation of D-scores as primarily reflecting associative memory activation and highlight the need to consider multiple cognitive processes when assessing implicit biases.