Two Replication Studies of a Time-Reversed (Psi) Priming Task and the Role of Expectancy in Reaction Times

Two experiments involving an international collaboration ofexperimenters sought to replicate and extend a previously publishedpsi experiment on precognition by Daryl Bem that has been the focusof extensive research. The experiment reverses the usual cause–e! ectsequence of a standard psychology experiment using priming and reactiontimes. The preregistered con" rmatory hypothesis is that response timesto incongruent stimuli will be longer than response times to congruentstimuli even though the prime has not yet appeared when the participantrecords their judgments. The con" rmatory hypothesis for Experiment 1was not supported. Exploratory analyses indicated that those participantswho completed the English-language version rather than a translationshowed a signi" cant e! ect, as was the case in the original study; nosigni" cant departure from chance was found in data involving non-English translations. Experiment 2 sought to enhance the predicted e! ectby having each participant read either a pro-psi or an anti-psi statementat the beginning of the experiment to test the hypothesis that a pro-psistatement would produce a larger e! ect than an anti-psi statement. Theresults did not support the primary psi hypothesis and there was no e! ectin the English-language sample. However, there was mixed support forthe e! ect of the psi statement on performance; those participants whoreceived the pro-psi statement had a greater psi score than those whoreceived the anti-psi statement. As in the original experiment, neitherthe experimenters’ nor participants’ beliefs were consistently associatedwith the dependent measure. In sum, the pre-registered con" rmatoryhypotheses were not supported. The importance of the personalityvariable Sensation Seeking, a component of extraversion, as a correlateof psi performance is discussed as are the challenges and implicationsfor international collaborations and replication in controversial science.