Studies reveal that the processing of implicit attitudes could be affected by individual differences in cognitive fluency, as well as by the presence of stereotype threat induced when subjects were primed with negative prejudices about their own social group. Using a previously proposed computational model of human performance on the Implicit Association Test, we examine possible processing mechanisms in which cognitive fluency and stereotype threat could influence the processing of implicit attitudes. Our goal is to extend the model to provide a cohesive and computationally plausible account for these effects; this is achieved by manipulating several model parameters that are analogous to human cogni-tive ability (in terms of processing speed and information retention ability) and shifts in confidence criteria for decision-making.