Daryl Bem jumped into the headlines around 18 months ago after his research offering evidence of precognition made news around the world. Discover magazine profiled Bem for their March 2012 issue, and for those interested the article has now been posted online. The profile delves into Bem the man – a former magician/mentalist turned respected psychology professor, turned parapsychology researcher:
Over the years, Bem cemented his reputation as a rebel by floating other controversial theories on topics such as personality and sexual orientation. His own personal life was also decidedly unconventional. Despite being married to a woman, Bem never hid from his family the fact that he is gay. A few years ago, he explained this conjugal conundrum in an Internet posting (pdf) distinguishing between romantic love and sexual attraction, arguing that many individuals—like himself—fall in love with a person of the “wrong” gender.
Even in the context of a career of irreverence, there was little to suggest that Bem would end up defending the possibility of extrasensory perception, or ESP, which most mainstream scientists consider unworthy of serious inquiry. Through most of his career, he was as dubious about telepathy (mind reading) or precognition (seeing the future) as any of his colleagues.
Then data changed his mind.
Bem’s article has created a storm of controversy regarding both the use of statistics in the field of psychology (as the WSJ vapidly says, “if you can use statistics to demonstrate that people are able to predict the future, there must be something wrong with your statistics”), as well as the failure of psychological journals to publish replications of controversial research (in this case, the negative replication by Ritchie, Wiseman and French). The latter point has escalated to such an extent that it is the cover story on the latest issue of The Psychologist, which features a debate over the replication controversy, including input from Bem himself. His article and others are available to read in the online sample of the mag, which I’ve embedded below (you’ll probably need to fullscreen it to view properly). I’ve also extracted a couple of choice quotes from Bem beneath the embed, as I think they’re worth pointing out:
The coverage of [the negative replication] has revealed many longstanding misunderstandings about replication – held even by those who should know better.
The first misunderstanding is the sheer overestimation of how likely it is that any replication attempt will be successful, even if the claimed effect is genuine.
…Second, it takes a long time for enough replications to accumulate to draw any firm conclusions. Wiseman set up an online registry for those planning to replicate any of my experiments. As he noted: ‘We will carry out a meta-analysis of all registered studies…that have been completed by 1 December 2011.’ The deadline was only a few months after my article appeared, and by then only three experiments other than those by Ritchie et al. had been reported. Two of them had successfully reproduced my original findings at statistically significant levels, a fact known to Ritchie et al., but not mentioned in the literature review section of their report…
…In mainstream psychology it takes several years and many experiments to determine which variables influence the success of replications.
…Finally, I believe that some major variables determining the success or failure of replications are likely to be the experimenters’ expectations about, and attitudes toward, the experimental hypothesis. Psychologists seem to have forgotten Robert Rosenthal’s extensive and convincing demonstrations of this in mainstream psychology during the 1960s. The same effect has been observed in psi experiments as well. Ironically, Wiseman, a psi-skeptic, has himself participated in a test of the experimenter effect in a series of three psi experiments in which he and psi-proponent Marilyn Schlitz used the same subject pool, identical procedures, and were randomly assigned to sessions. Schlitz obtained a significant psi effect in two of the three experiments whereas Wiseman failed to obtain an effect in any of the three…
…The existence of such experimenter effects does not imply that psi results are unverifiable by independent investigators, but that we must begin to systematically include the experimenters’ attributes, expectations and attitudes as variables.