Changing the affective valence of the stimulus items influences the IAT by re-defining the category labels

The Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) is a computer-based categorization task that measures concept association strengths. Greenwald et al. (1998) demonstrated that participants completed the categorizations more quickly when pleasant and flower shared a response key than when pleasant and insect shared a response key, and when pleasant and White shared a response key than when pleasant and Black shared a response key. In Study 1, we reversed the typical IAT effect for flowers and insects, and eliminated the typical IAT effect for White and Black, by changing the affective valence of the stimulus items. In Study 2, we replicated the reversibility effect for an animal and plant IAT, and supported a category re-definition hypothesis. Our results have implications for understanding the IAT, and suggest that the IAT not only measures stereotypic responses, but can also be influenced by individuating information of the stimulus items.