Feeling the Future: Evidence for Precognition

[Alex]

Feeling the Future: Experimental Evidence for Anomalous Retroactive Influences on Cognition and Affect 
Daryl J. Bem
Cornell University
http://dbem.ws/FeelingFuture.pdf

The term psi denotes anomalous processes of information or energy transfer that are currently unexplained in terms of  known physical or biological mechanisms. Two variants of psi are precognition (conscious cognitive awareness) and premonition (affective apprehension) of a future event that could not otherwise be anticipated through any known inferential process. Precognition and premonition are themselves special cases of a more general phenomenon: the anomalous retroactive influence of some future event on an individual’s current responses, whether those responses are conscious or nonconscious, cognitive or affective. This article reports 9 experiments, involving more than 1,000 participants, that test for retroactive influence by “timereversing” well-established psychological effects so that the individual’s responses are obtained before the putatively causal stimulus events occur. Data are presented for 4 time-reversed effects: precognitive approach to erotic stimuli and precognitive avoidance of negative stimuli; retroactive priming; retroactive habituation; and retroactive facilitation of recall.  All  but one of the experiments yielded statistically significant results; and, across all 9 experiments, Stouffer’s z = 6.66, p = 1.34 × 10-11 with a mean effect size (d) of 0.22.  The individual-difference variable of stimulus seeking, a component of extraversion, was significantly correlated with psi performance in 5 of the experiments, with participants who scored above the midpoint on a scale of stimulus seeking achieving a mean effect size of 0.43. Skepticism about psi, issues of replication, and theories of psi are also discussed.

Keywords:  psi, parapsychology, ESP, precognition, retrocausation

Correspondence concerning this article should be addressed to Daryl J. Bem, Department of Psychology, Uris Hall, Cornell University, Ithaca, New York 14853. [e-mail]

Journal of Personality and Social Psychology, in press.          
© 2010 American Psychological Association
http://www.apa.org/pubs/journals/psp/index.aspx               
This article may not exactly replicate the final version published in the APA journal. It is not the copy of record.



NO EVIDENCE FOR PSI

Why Psychologists Must Change the Way They Analyze Their Data: The Case of Psi
Eric-Jan Wagenmakers, Ruud Wetzels, Denny Borsboom, & Han van
der Maas
University of Amsterdam
http://dbem.ws/FeelingFuture.pdf

Abstract
Does psi exist? In a recent article, Dr. Bem conducted nine studies with over a thousand participants in an attempt to demonstrate that future events retroactively affect people’s responses. Here we discuss several limitations of Bem’s experiments on psi; in particular, we show that the data analysis was partly exploratory, and that one-sided p-values may overstate the statistical evidence against the null hypothesis. We reanalyze Bem’s data using a default Bayesian t-test and show that the evidence for psi is weak to nonexistent. We argue that in order to convince a skeptical audience of a controversial claim, one needs to conduct strictly confirmatory studies and analyze the results with statistical tests that are conservative rather than liberal. We conclude that Bem’s p-values do not indicate evidence in favor of precognition; instead, they indicate that experimental psychologists need to change the way they conduct their experiments and analyze their data.

Keywords: Confirmatory Experiments, Bayesian Hypothesis Test, ESP.

Correspondence concerning this article may be addressed to Eric–Jan Wagenmakers, University of Amsterdam, Department of Psychology, Roetersstraat 15, 1018 WB Amsterdam, the Netherlands. Email address: [e-mail]. Note that this is a revised version of a previous draft that was accepted pending revision for Journal of Personality and Social Psychology.



Alex's comment: 這裡有兩篇論文。頭一篇指有實驗證據顯示人某程度上能預知未來（或被未來影響）！第二篇則反駁，指實驗數據有漏洞，實未能證實該聲稱。