Belief in the paranormal: Probability judgements, illusory control, and the ‘chance baseline shift’

Possible reasons for belief in the paranormal are discussed and two hypotheses suggested. The first ‐that some belief in psi arises from misjudgements of probability ‐ predicts more errors in probability tasks among believers (sheep) than disbelievers (goats). In two experiments subjects completed various computer‐controlled probability tasks. In the first sheep performed worse than goats on most tasks and were significantly worse at responding appropriately to changes in sample size. In Expt 2 sheep were significantly worse at questions involving sampling. The second hypothesis is that some belief in psi arises from an illusion of control. Previous studies have shown a greater illusion of control among sheep in psi tasks (even when no psi occurs). We predicted the same effect in tasks not overtly involving psi. This was confirmed in Expt 3, using a computer‐controlled coin‐tossing task. Half the trials allowed for subject control of the coin and half did not. Sheep felt that they were exercising greater control than goats (irrespective of actual control) but estimated they had scored fewer hits. This could be explained if sheep misjudged chance scoring level. This was tested and sheep were found to underestimate chance scores. This ‘chance baseline shift’ could underlie the illusion of control and the belief in psi. No evidence of psi was found.