Daryl Bem

[[File:DarylBem (cropped).jpg|thumb|right|165px|Bem speaking at the 1983 [[Committee for Skeptical Inquiry]] (CSICOP) conference]]
{{parapsychology|1}}
'''Daryl J. Bem''' {{lived|1938}}, a respected social [[psychologist]], is more well known among skeptics for his investigations of the [[paranormal]]. His most famous study is titled "Feeling the Future: Experimental Evidence for Anomalous Retroactive Influences on Cognition and Affect",<ref>[https://pdfs.semanticscholar.org/79ec/e4f787af713d82924e41d8c17ab130f4b22d.pdf Feeling the Future: Experimental Evidence for Anomalous Retroactive Influences on Cognition and Affect.] Cornell University, 2011.</ref> and the most famous subset of these is the "[[porn]]" experiment. When provided two hidden images, participants were able to correctly select the "arousing" image 53.1% of the time (more than the 50% predicted by chance). Afterwards, participants were shown which image was porn and which was not. Bem argues that this (and various other tests) constitutes evidence for "[[Precognition|retroactive facilitation of recall]]" &mdash; or, people recalling events before they have happened.

However, [[Reproducibility|replication]] has proven Bem's [[hypothesis]] wrong:<ref>''Psychology Today,'' October 2012.</ref>

{{quotebox| Two papers (Galak, LeBoeuf, Nelson, & Simmons, 2012; Ritchie, Wiseman, & [[Chris French|French]], 2012) have since been published reporting attempts to replicate these experiments. Together these two papers report the results of 10 separate experiments using Bem's methods with a much larger combined sample. Only one of the ten experiments produced a significant result, although the authors (Galak, et al., 2012) report that when the results of their seven experiments were combined the overall effect size was close to zero. Additionally, Galak et al. performed a [[meta-analysis]] of all known published and unpublished attempts (comprising over 4,000 participants) to replicate Bem's retroactive facilitation of recall studies. The overall average effect size was not significantly different from zero.}}

Regardless of whether Bem's original study was designed well (and there are some indeed problems<ref>[http://www.talyarkoni.org/blog/2011/01/10/the-psychology-of-parapsychology-or-why-good-researchers-publishing-good-articles-in-good-journals-can-still-get-it-totally-wrong/ The psychology of parapsychology, or why good researchers publishing good articles in good journals can still get it totally wrong.] www.talyarkoni.org, 10 January 2011.</ref>), it has not stood the test of time.

==Feeling the Future==

''Feeling the Future: Experimental Evidence for Anomalous Retroactive Influences on Cognition and Affect'' is a paper submitted to and published in the ''Journal of Personality and Social Psychology'' by [[Daryl J. Bem]] of Cornell University that claims to offer strong evidence for the case of [[precognition]] in humans.<ref name=newsci>''New Scientist'', [http://www.newscientist.com/article/dn19712-evidence-that-we-can-see-the-future-to-be-published.html "Is this evidence that we can see the future?"], Peter Aldhous, 11 November 2010.</ref> It gained some notoriety during its "in press" phase in late 2010, with several [[pop science]] organisations and blog posts covering the experiment and attempting to understand it.

===Methodology===
The paper introduces some ingenious methodologies for rigorous study of certain kinds of [[psychic]] claims. The ingenious part comes from taking well-established [[psychological]] tests and ''reversing'' the order that the individual tests are administered. For instance, in one test, participants are asked to type certain words, selected at [[random]] from a list, and then are asked to recall words from the full list. The result is that they are capable of recalling more of the words that they had previously typed. In Bem's research, this is turned on its head: students were asked to recall words from a list and ''then'' asked to type a random selection of them. The result being that these students recalled the words that they would ''later'' type &mdash; the ones selected at random that they had no prior knowledge of at the time of the recall test. This suggests that their minds were somehow aware of what words they would experience in the future and selected them from the full list in advance!

However, the [[statistical]] analysis and subject selection criteria are highly suspect, and the statistically significant effects are likely a product of [[experimenter bias]].

===Specific criticisms===
A response by E.J. Wagenmakers ''et al.'' highlights some of the major issues that call into question the validity of the analysis by Bem.<ref>[https://www.ejwagenmakers.com/2011/WagenmakersEtAl2011_JPSP.pdf "Why Psychologists Must Change the Way They Analyze Their Data: The Case of Psi: Comment on Bem (2011)"] doi:10.1037/a0022790</ref>

*Bem has published his own research methodology and encourages the formulation of [[hypotheses]] ''after'' data analysis. This form of ''[[post-hoc fallacy|post-hoc]]'' analysis makes it very difficult to determine accurate statistical significance. It also explains why Bem offers specific hypotheses that seem odd ''[[a priori]]'', such as erotic images having a greater precognitive effect. Constructing hypotheses from the same data range used to test those hypotheses is a classic example of the [[Texas sharpshooter fallacy]].
*The paper uses the [[fallacy of the transposed conditional]] to make the case for [[psi]] powers, essentially mixing up the difference between the probability of data given a hypothesis versus the probability of a hypothesis given data. 
*Wagenmakers' analysis of the data using a Bayesian ''t''-test removes the significant effects claimed by Bem.

Any new result in any field of science requires extensive independent replication before it can be accepted as valid. This is no different for [[psychic]] powers, drug studies, or theories of [[physics]]. At least one [[Reproducibility|replication]] of one of the tasks Bem used has failed to show significance,<ref name=newsci /> and hopefully others will attempt additional replications. Researcher Richard Wiseman is attempting to create a registry of replication attempts<ref>[https://web.archive.org/web/20110508164224/http://www.richardwiseman.com/BemReplications.shtml Are you conducting a replication of Daryl Bem's 'Feeling the Future' experiments?]</ref> to control for [[publication bias]].

In the end, the paper offers some promising methods, but should not be taken as evidence for precognition without extensive independent replication of the results, particularly since there are significant questions about the introduction of bias into the analysis of the data.

An analysis published in ''Psychonomic Bulletin & Review'' found statistical evidence of publication bias in Bem's reported results.<ref>Francis G (2012). [http://www2.psych.purdue.edu/~gfrancis/Publications/GFrancis-R1.pdf Too good to be true: Publication bias in two prominent studies from experimental psychology]. Psychonomic Bulletin & Review 19(2): 151–156. doi:10.3758/s13423-012-0227-9.</ref>

In March of 2012, three independent failed replication attempts by Stuart J. Ritchie, Richard Wiseman, and [[Chris French]] were published in ''PLoS ONE''.<ref>Ritchie SJ, Wiseman R, French CC (2012). [https://web.archive.org/web/20120317183848/http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033423 Failing the Future: Three Unsuccessful Attempts to Replicate Bem's 'Retroactive Facilitation of Recall' Effect]. ''PLoS ONE'' 7(3): e33423. doi:10.1371/journal.pone.0033423</ref> The paper also noted a failed replication published in the ''Journal of the Society for Psychical Research''. Bem tried to [[special pleading|brush it off]] by suggesting that because the group attempting replication was [[skepticism|skeptical]] this would negatively influence the results.<ref>[https://web.archive.org/web/20121029123123/http://doubtfulnews.com/2012/03/bems-psychic-study-cast-into-doubt-as-it-fails-replication-attempts/ Bem's psychic study cast into doubt as it fails replication attempts], ''[[Doubtful News]]''.</ref> According to the paper Bem presented at the Parapsychological Association 46<sup>th</sup> Annual Convention in 2003, he had actually already tested for this possibility and found that a researcher's skepticism had no such effect.<ref>Bem, D. J. (2003). Precognitive habituation: Replicable evidence for a process of anomalous cognition. Proceedings of Presented Papers: The Parapsychological Association 46<sup>th</sup> Annual Convention. 6-20.</ref> The group had substantial problems trying to get their negative results published, several prominent journals refused to consider publishing a replication, and another journal rejected the paper after a negative report from one referee was later confirmed to be Daryl Bem himself.<ref>Chris French (15 March 2012). [http://www.guardian.co.uk/science/2012/mar/15/precognition-studies-curse-failed-replications Precognition studies and the curse of the failed replications]. ''The Guardian''.</ref>

A test of Bem's "retroactive priming" published in ''Memory & Cognition'' found no evidence of any such effect.<ref>[https://web.archive.org/web/20150414223911/http://www.springerlink.com/content/w6x350001121h6q7/ Feeling the past: The absence of experimental evidence for anomalous retroactive influences on text processing].</ref>

Bem has published a detailed response to Wagenmakers ''et al.'' in ''Journal of Personality and Social Psychology''.<ref>Bem D (2011). Must Psychologists Change the Way They Analyze Their Data? ''Journal of Personality and Social Psychology'' 101(4), 716–719 doi: 10.1037/a0024777.</ref> Bem ''et al'' respond to other critics and present a meta-analysis of 90 experiments in a paper currently under review.<ref>Bem D et al.(2014) [https://web.archive.org/web/20150414223920/http://dbem.ws/FF%20Meta-analysis%206.2.pdf Feeling the Future: A Meta-analysis of 90 Experiments on the Anomalous Anticipation of Random Future Events.] Under editorial review.</ref>

==Further reading==
Unpublished failed replications:
*Jeff Galak and Leif D. Nelson (2010). [http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1699970 A Replication of the Procedures from Bem (2010, Study 8) and a Failure to Replicate the Same Results]
*Steve Snodgrass (2010). [http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1935942 Examining Retroactive Facilitation of Recall: an Adapted Replication of Bem (2011, Study 9) and Galak and Nelson (2010)].
*Galak, LeBoeuf, Nelson and Simmons (2012). [http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2001721 Correcting the Past: Failures to Replicate Psi].
*[http://www.youtube.com/watch?&v=0Tdiu5kwjKs#t=50m46s 2011 panel discussion with Daryl Bem, Jonathan Schooler and Samuel Moulton]: Moulton's presentation describes a failed replication of experiment 6 and issues with Bem's reported results. Bem provided Moulton with the software and stimuli to conduct a replication in 2004. Moulton used a greater sample size, but found an insignificant effect in the opposite direction to Bem.
* Wagenmakers et al. preliminary results from failed replication of experiment 1. [https://web.archive.org/web/20140605100944/http://dl.dropbox.com/u/31749173/PSI%20OP6119.pdf] (Dutch)

Bem's 2003 and 2005 preliminary reports on these experiments at the Parapsychological Association Convention:
*Bem, D. J. (2003). [http://www.infoamerica.org/documentos_pdf/bem05.pdf Precognitive habituation: Replicable evidence for a process of anomalous cognition]. Proceedings of Presented Papers: The Parapsychological Association 46th Annual Convention. 6-20.
*Bem, D. J. (2005). [https://web.archive.org/web/20060907094710/http://www.psych.cornell.edu/sec/pubPeople/djb5/PrecogAversion.pdf Precognitive aversion]. Proceedings of Presented Papers: The Parapsychological Association 48th Annual Convention. 31–35.

==See also==
*[[Texas sharpshooter fallacy]]

==External links==
*[https://archive.ph/Kybzt Feeling the Future] (in press version)
*[http://psycnet.apa.org/journals/psp/100/3/407/ Journal of Personality and Social Psychology, 100, 407-425. (Published version, March 2011)]
*James Alcock. [http://www.csicop.org/specialarticles/show/back_from_the_future Back from the Future: Parapsychology and the Bem Affair.] ''Skeptical Inquirer'', Jan. 6 2011.
*[http://archive.ph/LnUSK Daryl Bem's Home Page] (archive snapshot)

==References==
{{reflist|2|80%}}

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