The implicit association test outperforms the extrinsic affective Simon task as an implicit measure of inter-individual differences in attitudes.

We used both the Extrinsic Affective Simon Task (EAST) and the Implicit Association Test (IAT) as implicit measures of inter-individual differences in attitudes towards political parties (Experiment 1), food items (Experiment 2) and homosexuality (Experiment 3). IAT but not EAST scores were related in a meaningful manner to self-report measures of the corresponding attitudes (Experiments 1-3) and self-reported behaviour (Experiments 2 and 3). Whereas split-half reliability of the IAT scores was satisfactory, EAST scores overall had a low split-half reliability. The present results suggest that the EAST as introduced by De Houwer (2003b, Experimental Psychology) does not offer a good alternative for the IAT as an implicit measure of inter-individual differences in attitudes.