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

Two experiments involving an international collaboration of
experimenters sought to replicate and extend a previously published
psi experiment on precognition by Daryl Bem that has been the focus
of extensive research. The experiment reverses the usual cause–e! ect
sequence of a standard psychology experiment using priming and reaction
times. The preregistered con" rmatory hypothesis is that response times
to incongruent stimuli will be longer than response times to congruent
stimuli even though the prime has not yet appeared when the participant
records their judgments. The con" rmatory hypothesis for Experiment 1
was not supported. Exploratory analyses indicated that those participants
who completed the English-language version rather than a translation
showed a signi" cant e! ect, as was the case in the original study; no
signi" cant departure from chance was found in data involving non-
English translations. Experiment 2 sought to enhance the predicted e! ect
by having each participant read either a pro-psi or an anti-psi statement
at the beginning of the experiment to test the hypothesis that a pro-psi
statement would produce a larger e! ect than an anti-psi statement. The
results did not support the primary psi hypothesis and there was no e! ect
in the English-language sample. However, there was mixed support for
the e! ect of the psi statement on performance; those participants who
received the pro-psi statement had a greater psi score than those who
received the anti-psi statement. As in the original experiment, neither
the experimenters’ nor participants’ beliefs were consistently associated
with the dependent measure. In sum, the pre-registered con" rmatory
hypotheses were not supported. The importance of the personality
variable Sensation Seeking, a component of extraversion, as a correlate
of psi performance is discussed as are the challenges and implications
for international collaborations and replication in controversial science.