|Abstract/Results: ||ABSTRACT: |
It has been claimed that experimenter effects may account for inconsistent findings in the study of cognitive correlates of paranormal belief and in extrasensory perception (ESP) research. Skeptical investigators have generally found a negative correlation between cognitive ability and paranormal belief, but other investigators have failed to confirm these findings. In ESP research, skeptical investigators often find no evidence for ESP, whilst some psi proponents seem consistently to obtain positive evidence for ESP. Perhaps these inconsistent results may be due, in part, to the experimental context influencing participants’ responses during the session. The present study investigates these two strands by having two experimenters with differing attitudes towards the paranormal (RW and CW) each administer to 30 participants a paranormal belief questionnaire, two tests of cognitive ability (a syllogistic reasoning task and Raven’s matrices), and an ESP task. Participants were allocated to RW or CW in a counter-balanced fashion. The experimenter’s initial chat with participants was video-taped, then the experimenter administered the questionnaire and cognitive tasks to participants. Then each participant did the ESP task, which was video-taped. For this, the experimenter interviewed the participant and asked them to give their impressions of a short randomly-selected video clip that they would be shown at the end of the session. A single set of five target possibilities was used throughout the study. The experimenter ranked these according to their similarity with the participant’s impressions, then discovered the identity of the target clip for that session and played it to the participant for feedback. Results: For all 60 participants, a significant negative correlation was found between paranormal belief and syllogisms performance (r = -.28, N = 59, p = .03, 2-t). This correlation was attributable to just one of the experimenters (CW, r = -.45, N = 30, p = .01, 2-t; RW, r = -.08, N = 29, p = .70, 2-t), and the experimenters’ correlations significantly differed on two of the belief sub-scales (traditional religious beliefs, and spiritualism), thus demonstrating an experimenter effect for this measure. No correlation was found between paranormal belief and performance on the Matrices task. Additional post hoc analyses were conducted to clarify the mechanism underlying the belief-cognitive ability correlation. A median split was used to divide participants into believer and disbeliever groups. There was no significant difference between the belief scores of CW’s vs RW’s believers, nor between CW’s vs RW’s disbelievers. Therefore there was no indication that participants were shifting their belief scores during the session. CW’s and RW’s believers differed on their mean syllogisms scores (t = 2.16, p = .04, 2-t), while CW’s and RW’s disbelievers did not differ in their syllogisms scores (t = .47, p = .64, 2-t). This suggests that in this study it was the psi believers who were shifting their performance on the syllogisms task. A similar pattern was found post hoc for the matrices task. No evidence was obtained of ESP, nor was there any evidence of an experimenter effect for the ESP task.