A Tutorial on Response-Time Extended Multinomial Processing Tree Models in Social Cognition

Multinomial processing tree (MPT) models can provide novel insights into the cognitive processes underlying a wide variety of social cognitive judgments and behaviors. In previous research, MPT models have been used to disentangle the contributions of multiple latent processes to tasks configured to assess moral reasoning, processing fluency, decision-making, implicit biases, and social categorization, among many other topics. However, until recently, MPT models were limited in their application to categorical data. New methodological advances extend traditional MPT estimation methods by incorporating reaction time data, thereby expanding the breadth and depth of questions that can be investigated. This article provides a user-friendly step-by-step tutorial for response-time extended MPT methods with annotated code and data, using the Implicit Association Test as a working example.