Feeling the future: A meta-analysis of 90 experiments on the anomalous anticipation of random future events

Abstract

In 2011, one of the authors (DJB) published a report of nine experiments in the Journal of Personality and Social Psychology purporting to demonstrate that an individual's cognitive and affective responses can be influenced by randomly selected stimulus events that do not occur until after his or her responses have already been made and recorded, a generalized variant of the phenomenon traditionally denoted by the term precognition. To encourage replications, all materials needed to conduct them were made available on request. We here report a meta-analysis of 90 experiments from 33 laboratories in 14 countries which yielded an overall effect greater than 6 sigma, z = 6.40, p = 1.2 × 10 (-10 ) with an effect size (Hedges' g) of 0.09. A Bayesian analysis yielded a Bayes Factor of 1.4 × 10 (9), greatly exceeding the criterion value of 100 for "decisive evidence" in support of the experimental hypothesis. When DJB's original experiments are excluded, the combined effect size for replications by independent investigators is 0.06, z = 4.16, p = 1.1 × 10 (-5), and the BF value is 3,853, again exceeding the criterion for "decisive evidence." The number of potentially unretrieved experiments required to reduce the overall effect size of the complete database to a trivial value of 0.01 is 544, and seven of eight additional statistical tests support the conclusion that the database is not significantly compromised by either selection bias or by " p-hacking"-the selective suppression of findings or analyses that failed to yield statistical significance. P-curve analysis, a recently introduced statistical technique, estimates the true effect size of our database to be 0.20, virtually identical to the effect size of DJB's original experiments (0.22) and the closely related "presentiment" experiments (0.21). We discuss the controversial status of precognition and other anomalous effects collectively known as psi.

Examining the nature of retrocausal effects in biology and psychology

“…This reliance on nonconscious processing is also shared with PAA. The idea that nonconscious processes are likely to subserve implicit precognition is also supported by the results from a recent meta-analysis of 90 implicit precognition experiments [21]. As was the case for the recent PAA meta-analysis [7], the implicit precognition meta-analysis revealed a very small effect size (0.09, Hedges' g, Confidence Intervals: 0.06 to 0.11), which was nonetheless a six-sigma effect.…”

“…However, it turns out that implicit precognition experiments using tasks that required slower, deliberate responses did not produce reliable effects (0.03, Hedges' g, 95% Confidence Intervals: -0.01 to 0.08), while experiments requiring faster responses, when considered independently, produced a larger effect size (0.11, Hedges' g, 95% Confidence Intervals: 0.08 to 0.14) and were clearly responsible for the significance of the entire dataset. Thus it appears that faster responding facilitates implicit precognition, a result that was interpreted by Bem et al [21] to mean that implicit precognition is largely served by nonconscious processes, which are notably faster than conscious ones.…”

“…It showed that men had a larger precognition effect than women, but this difference was not significant [22]. In the recent meta-analysis of implicit precognition already discussed, gender was not described as a factor, but the authors provided no reports of gender or age effects [21].…”

“…However, the test employed slow and consciously deliberated responses, words typed by the participants without a time limit, as the dependent variable. As mentioned previously, although Bem's original retroactive-facilitation-of-recall experiment produced a significant effect, it has been difficult to replicate, as have other implicit precognition experiments using similarly slow response protocols [21]. Thus it seemed reasonable to attempt to replicate the same experiment using a protocol in which responses are faster (i.e., a speeded-response protocol), and doing so provided an opportunity to examine potential gender differences.…”

Open access as a mechanism of revolutionary science and the limitations of data

“…The meta-analysis excludes non-significant studies that address awareness of a potential 589 retroactive stimulus (Bem et al 2015). Significant results are restricted to implicit stimuli, but 590 there is no a priori reason for this convenient decision on the part of the authors.…”