Paranormal Effects and Behavioural Characteristics of Participants in a Forced-Choice Psi Task: Ertel's Ball Selection Test under Scrutiny

In a previous study (Storm, Ertel, & Rock, 2013), we demonstrated that Ertel's (2005b,c) Ball Selection Test (a.k.a. the Ball Test) can be used to test Reactance Theory (Brehm & Brehm, 1981), and the Sheep-Goat Effect (SGE; the tendency for believers ['sheep'] to psi-hit and non-believers ['goats'] to psi-miss). The Ball Test is a forced-choice psi task involving the blind selection of numbered pingpong balls after numbers are called by the participant (a hit is a match between a 'called' number and a 'selected' ball number). According to Reactance Theory, when an individual's freedom is threatened through some form of coercion, we may expect reactance, which is "a motivational state aimed at restoring the threatened freedom" (Silvia, 2005, p. 277). Reactance may explain the SGE. In that study (N = 82), we found a significant forced-choice hit rate of 21.06% where PMCE = 20% (p = .002). Participants were randomly assigned to a control condition (n = 42) or treatment (n = 40) condition requiring them to read a statement that induced reactance. We found a significant reactance effect, and a significant SGE. In the present study, we sought answers to some crucial questions concerning the ball test's validity, including possible displacement effects, and possible biases in numbercalling and selection-behaviour. We found that participants did avoid calling numbers if they had just called them or just selected them from the bag. We found no evidence of hits being mere artifacts caused by sensory leakage or mnemonic aids.