Many methods for reducing implicit prejudice have been identified, but little is known about their relative effectiveness. We held a research contest to experimentally compare interventions for reducing the expression of implicit racial prejudice. Teams submitted 17 interventions that were tested an average of 3.70 times each in 4 studies (total N = 17,021), with rules for revising interventions between studies. Eight of 17 interventions were effective at reducing implicit preferences for Whites compared with Blacks, particularly ones that provided experience with counterstereotypical exemplars, used evaluative conditioning methods, and provided strategies to override biases. The other 9 interventions were ineffective, particularly ones that engaged participants with others' perspectives, asked participants to consider egalitarian values, or induced a positive emotion. The most potent interventions were ones that invoked high self-involvement or linked Black people with positivity and White people with negativity. No intervention consistently reduced explicit racial preferences. Furthermore, intervention effectiveness only weakly extended to implicit preferences for Asians and Hispanics.

In the present study two separate stimulus–response compatibility effects (functional affordance and Simon-like effects) were investigated with centrally presented pictures of an object tool (a torch) characterized by a structural separation between the graspable portion and the goal-directed portion. In Experiment 1, participants were required to decide whether the torch was red or blue, while in Experiment 2 they were required to decide whether the torch was upright or inverted. Our results showed that with the same stimulus two types of compatibility effect emerged: one based on the direction signalled by the goal-directed portion of the tool (a Simon-like effect as observed in Experiment 1), and the other based on the actions associated with an object (a functional affordance effect as observed in Experiment 2). Both effects emerged independently of the person's intention to act on the stimulus, but depended on the stimulus properties that were processed in order to perform the task.