The Implicit Association Test (Greenwald, McGhee, & Schwartz, 1998) is a categorization task intended to measure the strength of associations between concepts. The present research investigated the influence of individual stimuli on TAT effects. Exploring implicit attitudes of East and West Germans, we systematically manipulated relatedness of target stimuli to the attribute dimension and, simultaneously, relatedness of attribute stimuli to the target dimension. Two experiments demonstrate the influence of stimulus associations as one source that drives TAT effects. Depending on the strength and the direction of these cross-category associations, the result was either stronger TAT effects or a decline of TAT effects. Implications for theoretical models as well as for the interpretation of TAT effects are discussed. (c) 2005 Elsevier Inc. All rights reserved.