Why does the IAT reveal a preference for stimuli said to be paired with an unpleasant sound? Stalking the unexpected

The Implicit Association Test (IAT) is the most widely used measure to assess automatic evaluations. One classic phenomenon that has been well established both using the IAT and self-report measures of liking is evaluative conditioning (EC), which refers to a change in the evaluation of a stimulus due to its pairing with another stimulus. Research has documented that EC can also occur when participants are merely informed about upcoming stimulus pairings. In a recent study, participants reported a more negative evaluation of non-words that were instructed to be followed by an unpleasant sound compared to non-words that would not to be followed by this sound (De Houwer, Mattavelli, & Van Dessel, 2019). Interestingly, however, an unexpected pattern was observed on an IAT, that is, a preference for the stimulus said to be followed by the sound. We report three pre-registered experiments (N = 650) in which we manipulated different aspects of the procedure such as the stimuli, instructions, and the measure, but that still revealed the same dissociation. Based on three pilot experiments (N = 92), we then conducted a registered report study (Experiment 4) testing whether the unexpected effect depends on how the USs are labelled in the instructions. Although describing the aversive sound as negative eliminated the unexpected IAT effect, the type of instruction only had a weak impact on IAT effects. These results are in line with prior evidence showing that IAT scores are malleable