The reductionist/anti-reductionist debate about testimonial justification (and knowledge) can be taken to collapse into a controversy about two kinds of underlying monitoring mechanism. The nature and structure of this mechanism remains an enigma in the debate. We suggest that the underlying monitoring mechanism amounts to emotion-based stereotyping. Our main argument in favor of the stereotype hypothesis about testimonial monitoring is that the underlying psychological mechanism responsible for testimonial monitoring has several conditions to satisfy. Each of these conditions is satisfied by (...) our “hot” stereotypical capacities. Intergroup emotions play a key role here. Intergroup emotions inform the agent about which candidate stereotype is better suited to the current situation. Emotions serve as evidence that makes a certain stereotype and its particular profile of features more or less expected. (shrink)