Evaluating the impact of hypnotic suggestion on implicit biases: an age implicit association test study

Van Dessel and De Houwer (2019) found evidence to indicate that, in some instances, hypnosis can lead to reduced measures of implicit bias. However, I argue that their departures from standard hypnosis paradigms limit their ability to draw meaningful conclusions concerning the unique role of hypnotic suggestion in this reduction. Given the theoretical significance of their results, I aimed to conceptually replicate their findings across two studies that explored the capacity of hypnosis to moderate implicit beliefs as measured through performance on an Age Implicit Association Test (A-IAT). In Study 1, high (N = 27) and low (N = 15) hypnotizable student participants completed an A-IAT at baseline, following a hypnotic suggestion, and 24 hours later. Reductions of the IAT effect were observed in both highs and lows, indicating that the reduction was a product of the suggestion rather than an effect of hypnosis. To test the generalizability of this result, a second study was conducted with participants from the general population. In Study 2, participants (N = 132) completed an A-IAT at baseline and following a hypnotic suggestion. Evidence suggested that there were performance-related differences between the high and low groups, although an analysis of trial RTs indicated that this result was caused by an IAT artifact rather than an effect of the hypnotic suggestion. I conclude that theories of hypnosis which do not allow for hypnosis to impact implicit beliefs can still explain performance in an IAT paradigm. The potential of online hypnosis is also discussed.