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In theory, the “everyone’s a little bit psychic” paradigm is fine. Instead of trawl-ing the population for high scorers, parapsychologists have people take part in various psi tests, pool their results, and hope for significant and replicable effects.

Unfortunately, in practice it hasn’t turned out to be quite so simple. After over six decades of experimentation in this paradigm, researchers have failed to reach a consensus about the existence of psi. Although a minority of parapsychologists argue that the evidence is overwhelming, most parapsychological researchers believe that it simply isn’t possible to answer the question with any certainty one way or the other. This lack of closure is due, in part, to the way in which null results are viewed at four key stages of the research process.

Stage 1: Cherry-Picking New Procedures

Parapsychologists frequently create and test new experimental procedures in an attempt to produce laboratory evidence for psi. These studies are most often car-ried out both by professional parapsychologists as exploratory investigations and by students as project work. Because there are no agreed-upon theoretical con-straints surrounding psi, it is possible to form a convincing-sounding argument to justify almost any new procedure. For example, researchers with psychoana-lytic leanings might think that psychic experiences involve the unconscious, and so argue that psi is especially likely to emerge during dreaming. Alterna-tively, psi can be viewed as an evolutionary survival mechanism that will operate best when people feel under some kind of threat, such as when they are placed in a room with a large spider. There again, one could adopt a neuropsychological stance, and argue that psychic ability is associated with right hemisphere func-tioning and thus should be enhanced after listening to relaxing music.

Most of these studies yield non-significant results and are either never published, or make it into a journal or conference proceedings but are quietly forgotten. Rather than being seen as evidence against the existence of psychic ability, such null findings are usually attributed to the experiment being carried out under non psi-conducive conditions. The pervasiveness of this practise is usually quickly revealed when chatting to those engaged in parapsychological research. Ask them what they are up to, and they will often describe an experi-ment involving some kind of new procedure, e.g., “I am looking to see if psi effects are especially strong among groups of professional artists at a New Age retreat” or

“I am looking at whether astute waiters score especially well on tests involving the remote detection of staring,” or “I am looking at whether people arriving late at a train station are especially likely to find that their train has been delayed.”

During my time in the field I have heard talk of large numbers of such studies, but only seen a minority make it into print or be presented at a conference.

Of course, it could be that the researchers did not actually get around to running the various studies. However, I suspect that in many cases the early results were not promising and thus the study was abandoned, or that the study was completed but did not yield significant results and so remains tucked away at the back of a file drawer. Interestingly, ask researchers engaged in these tests what they will con-clude if the study yields null results and they rarely mention disconfirmation of the psi hypothesis but instead explain that this would suggest that the new pro-cedure is not psi-conducive. Pursue the point by asking them how many null find-ings would convince them that psi does not exist and the silence is usually deafening.

Once in a while one of these studies produces significant results. The evidential status of these positive findings is impossible to judge because all too often they have emerged from a mass of non-significant studies. Nevertheless they are more likely than non-significant studies to be presented at a conference or published in a journal, usually viewed as tentative evidence for psi, and act as a catalyst for further work.

To my knowledge, only one paper has revealed an insight into the potential scale of this problem. Watt (2006) summarized all of the psi-related final year undergraduate projects that had been supervised by staff at Edinburgh University’s Koestler Parapsychology Unit between 1987 and 2007. Watt tracked down 38 projects, 27 of which predicted overall significant performance on a psi task. The work examined a range of new and established procedures, including, for example, dowsing for a hidden penny, the psychokinetic control of a visual display of a bal-loon being driven by a fan onto spikes, presentiment of photographs depicting emotional facial expressions, detecting the emotional state of a sender in a telepa-thy experiment, ganzfeld studies, and card guessing. Interestingly, Watt’s paper also demonstrated a reporting bias. Only 7 of the 38 studies had made it into the public domain, being presented as papers at conferences held by the Parapsycho-logical Association. All of these papers had predicted overall significant perfor-mance on the psi task. There was a strong tendency for researchers to make public those studies that had obtained positive findings, with just over 70%

(5 out of 7) of the studies presented at conference showing an overall significant result, versus just 15% (3 out of 20) of those that remained unreported.

Watt’s analysis, although informative, underestimates the total number of psi-related studies undertaken at Edinburgh University because it did not include projects undertaken by students prior to their final year, experiments run by post-graduate students and staff, or any work conducted before 1987. Multiply these figures by the number of researchers who have conducted and supervised psi research across the world over the last 60 years or so, and the scale of the issue becomes apparent.

This process is the “heads I win, tails you lose” principle in action, with researchers trying a large number of new procedures, only to ignore the sizable cata-logue of null findings and view the few positive results as being suggestive of psi.

Stage 2: Attempted Replications of “Successful” Procedures

Any procedure that seems to yield significant psi effects usually results in addi-tional follow-up studies that utilize that procedure. Although these addiaddi-tional studies occasionally take the form of strict replications, it is more usual for them to involve some form of variation (e.g., Braud, Smith, Andrew, & Willis, 1976).

These changes may be made for practical reasons or to explore the conditions that may influence the alleged effect. For example, if the original study into precogni-tive dreaming involved monitoring participants’ REM state and waking them whenever they had a dream, a follow-up study might involve giving them a good night’s sleep and asking them to recall all of their dreams in the morning. Like-wise, if the original study into the evolutionary roots of psi made participants feel anxious by placing them in a room with a large live spider, a follow-up experiment might involve showing them photographs of the aforementioned creepy-crawlies.

Similarly, if the original work into hemispheric processing involved participants listening to live music, a follow-up study might play them pre-recorded tracks.

If these follow-up studies obtain significant results, and do not appear to be due to any methodological or statistical problems, then the findings are seen as evidence for psi. However, any failure to replicate the original effect is often explained away in various ways.

They can, for example, be attributed to the procedural modifications rather than to the non-existence of psi. Again, because there are no theoretical con-straints surrounding psi, it is easy to produce convincing sounding arguments to explain how any changes might have produced null effects. For example, researchers may argue that people’s dream recall in the morning is less accurate than immediately after REM, that seeing a photograph of a spider does not pro-duce the same level of anxiety as the real thing, or that pre-recorded music lacks the psi-conducive impact of a live performance. Perhaps the most far-reaching version of this “get out of a null effect free” card involves an appeal to the

“experimenter effect,” (e.g., Roll & Williams, 2010) wherein any negative find-ings are attributed to the psi inhibitory nature of the researchers running the study (e.g., Van de Castle, 1989).

In addition to explaining away null findings via allegedly failed procedural modifications, some researchers also adopt an “any anomaly will do” attitude, and data-mine in an attempt to produce some kind of psi-related result. Suddenly the emphasis is shifted away from a main effect and toward, for example, gender differences, or those who had vivid dreams versus those who did not, or those who gave especially high anxiety ratings to the photographs of the spiders, or those who reported finding the recorded music particularly enjoyable. Although such post hoc data mining might help guide future work, it has little, if any, evi-dential value. Nevertheless, researchers often present it as tentative evidence in support of the psi hypothesis.

Once again, this entire process represents the “heads I win, tails you lose” princi-ple. Successful replications are seen as evidence of psi while null results are attrib-uted to the non psi-conducive conditions under which the replication was carried out, with many researchers then quickly scurrying around to find post hoc effects.

Stage 3: Meta-Analyses and Retrospective Data Selection

After several studies have been conducted using a new procedure, researchers usually carry out some form of meta-analytic review of the work (e.g., Watt, 1994). If the combined outcome of the studies is significant, and does not appear to be due to any methodological or statistical problems, then the research is viewed as evidence for psi. However, if the cumulative effect is non-significant, researchers often attribute this null effect to the “non psi-conducive” procedural variations described in the preceding section.

Perhaps more importantly, the procedurally heterogeneous collection of stud-ies usually presents researchers with an opportunity to “explain away” overall null effects by retrospectively identifying a sub-set of studies that used a certain pro-cedure. Although such post hoc data mining has little evidential value, researchers often offer it as tentative evidence in support of the psi hypothesis.

A striking illustration of this occurred in the late 1990s during a meta-analytic debate surrounding the ganzfeld psi studies. In 1999 Julie Milton and I published a meta-analysis of all ganzfeld studies that were begun after 1987 and published by the beginning of 1997, and noted that the cumulative effect was both small and non-significant (Milton & Wiseman, 1999). Some researchers criticized this analysis, noting that we had included all of the ganzfeld studies conducted during this period, and that we should have instead focused on those that had employed a “standard” procedure developed by parapsychologist Charles Honorton and his colleagues during a seminal set of ganzfeld studies conducted at the Psychophysical Research Laboratory (PRL) in the late 1980s. The difficulties with this approach were revealed when researchers were unable to settle on what would constitute a

“standard” set of procedures (Schmeidler & Edge, 1999). Eventually, Bem, Palmer, and Broughton (2001) set out to tackle this issue experimentally, asking several people to rate the degree to which the studies in our analysis had employed Honorton’s “standard” ganzfeld procedure and then correlating their ratings against the effect size of each study. Rather than provide their own description of

this “standard” procedure, Bem, Palmer, and Broughton had the raters read relevant sections in two previous papers describing the PRL studies. However, they also added a series of additional conditions, informing their raters, for example:

You should treat as standard the use of artistic or creative subject samples (as one of the most successful components of the PRL experiments used such a sample) or subjects having had previous psi experiences or having practised a mental discipline such as meditation (as such subjects were shown to be the best scorers in the PRL experiments). (p. 210)

The addition of participant selection as an allegedly “standard” condition was not mentioned in the “method” section of either of the papers describing the PRL work. Once again, it’s the “heads I win, tails you lose” principle.

Stage 4: Decline Effects and Repeating History

The alleged psi effects associated with a certain procedure frequently have a curious habit of fading over the course of repeated experimentation. Critics have argued that this is due to the researchers identifying and minimizing potential methodological and statistical flaws over time (e.g., Alcock, 2003, 2010). How-ever, some parapsychologists have come up with creative ways of avoiding this potential threat, arguing that such decline effects are either an inherent pro-perty of psi or that psychic ability really does exist but is inversely related to the level of experimental controls employed in a study (see Kennedy, 2003, for a review of this approach). This may represent the next paradigm shift in parapsy-chology. If this proves to be the case it will be yet another (and possibly final) instance of parapsychologists changing their model of psi in the face of null find-ings, moving from the current “everyone has it to a small amount” paradigm to an unfalsifiable, and some would say bizarre, psi as an “all-knowing but elusive force.”

Regardless, the decrease in alleged psi often causes researchers to abandon ship in search of a new procedure, placing them back to square one and ready to repeat history. This is not a new observation, with commentators remarking on this pattern throughout the history of the field. For example, writing over three decades ago, the parapsychologist Joseph Gaither Pratt (1978) noted:

One could almost pick a date at random since 1882 and find in the literature that someone somewhere had recently obtained results described in terms implying that others should be able to confirm the findings.. . . One after another, however, the specific ways of working used in these initially suc-cessful psi projects have fallen out of favor and faded from the research scene—except for the latest investigations which, one may reasonably sup-pose, have not yet had enough time to falter and fade away as others before them have done. (p. 129)

This constant “ship jumping” is one of the defining features of psi research, with new paradigms emerging every decade or so. Take, for example, the different trends in ESP research that have emerged over the years. Initial work, conducted between the early 1930s and late 1950s primarily involved card guessing experi-ments, in which people were asked to guess the identity of specially printed playing cards carrying one of five simple symbols (e.g., Rhine, 1948). By the mid-1960s researchers had realized that such studies were problematic to replicate and so turned their attention to the possibility of participants predicting the outcome of targets selected by machines (e.g., Forwald, 1969), and to dream telepathy (e.g., White, Krippner, & Ullman, 1968). In the mid 1970s and early 1980s the ganzfeld experiments and remote viewing took over as dominant paradigms (e.g., Honorton, 1977; Targ & Morris, 1982). In 1987, a major review of the area by parapsychologists K. Ramakrishna Rao and John Palmer argued that two sets of ESP studies provided the best evidence for the replicability of psi: the ganzfeld experiments and the differential ESP effect (wherein participants apparently score above chance in one condition of an experiment and below chance in another).

More recently researchers have shifted their attention to alleged presentiment effects, wherein participants appear to be responding to stimuli before they are pre-sented (e.g., Radin, 1997). It seems likely that the next new procedure is likely to adopt a neuropsychological perspective, perhaps focusing on EEG measurements or functional MRI scans as people complete psi tasks (e.g., Don & Moura, 2000;

Moulton & Kosslyn, 2008).

CONCLUSION

And so it goes on: around and around in circles, with researchers cherry-picking new procedures from a mass of chance results, varying any allegedly “successful”

procedures and then blaming these variations for any lack of replication, search-ing for pockets of post hoc significance whenever a meta-analysis produces a null result, explaining away decline effects as an inherent property of psi, and finally jumping into bed with the next new promising procedure. This giddy process results in an ambiguous data set that, just like the classic optical illusion of the old hag and attractive young woman, never contains enough information to allow closure in one direction or the other.

The good news is that the framework outlined above presents a way to move forward and rapidly reach closure on the issue. To achieve this, researchers should change the way in which they view null findings. They might stop trying numerous new procedures and cherry-picking those that seem to work, and instead identify one or two that have already yielded the most promising results.

They could stop varying these procedures, and instead have a series of labs carry out strict replications that are both methodologically sound and incorporate the most psi-conducive conditions possible. They could avoid the haunting spectre of retrospective meta-analysis by pre-registering the key details involved in each of the studies. And finally, they might agree to stop jumping ship, and instead

have the courage to accept the null hypothesis if the selected front-runners do not produce evidence of a significant and replicable effect.

My hope is that such a process will stop researchers from finding themselves forever perched on the fence parroting the hackneyed “there is enough evidence to justify further work, but not enough to conclude one way or the other” position.

They will instead put their feet on the ground and be the generation of experi-menters that were brave enough to give it their best shot. Finally, they will be the ones to discover whether psi actually exists.

REFERENCES

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Getting to grips with the paranormal (pp. 29–50). Charlottesville, VA: Imprint Academic.

Alcock, J. E. (2010). The parapsychologist’s lament. In S. Krippner & H. L. Friedman (Eds.), Mysterious minds: The neurobiology of psychics, mediums, and other extraordinary people (pp. 35–43). Santa Barbara, CA: Praeger.

Bem, D. J., Palmer, J., & Broughton, R. S. (2001). Updating the Ganzfeld database:

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Braud, W. G., Smith, G., Andrew, K., & Willis, W. (1976). Psychokinetic influences on random number generators during evocation of “analytic” vs. “nonanalytic” modes of information processing. In J. D. Morris, W. G. Roll, & R. L. Morris (Eds.), Research in Parapsychology 1975 (pp. 85–88). Metuchen, NJ: Scarecrow Press.

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New York: Parapsychological Foundation.

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A summary and hypotheses. Journal of Parapsychology, 67, 53–74.

Milton, J., & Wiseman, R. (1999). Does psi exist? Lack of replication of an anomalous

Milton, J., & Wiseman, R. (1999). Does psi exist? Lack of replication of an anomalous