Parapsychology has been unfairly sidelined, claims a new review of the field

A number of notable figures from psychology's past held an interest in parapsychology or psi (the study of mental phenomena that defy current scientific understanding), including William James, Alexander Luria, Binet, Freud, and Fechner. But today the field is cordoned off; and when it encroaches into mainstream publications, as with the "Feeling the Future" experiments conducted by Daryl Bem in 2012, furore typically follows. To sceptics, the fact that these experiments produced positive results is ipso facto proof that psychology's methods must be broken.

However, it's only logical to take this view if you have already ruled out the existence of psychic phenomena and, at least among the US public, the majority haven't. Even in the chronically suspicious British culture, one quarter of people have consulted a psychic. I too am personally quite open to the existence of such phenomena, so I've been eager for an accessible overview of the field of parapsychology as it currently stands. This is what parapsychology researcher Etzel Cardeña, Director of the Centre for Research on Consciousness and Anomalous Psychology at Lund University, attempts to provide in his new review in American Psychologist. 

One of the main areas that Cardeña focuses on is "anomalous cognition", which involves coming to know something without using the normal senses. Cardeña cites a pair of meta-analyses combining previous data that involved a forced-choice procedure popular in the middle of the last century (imagine a set up similar to Peter Venkman's experiment in Ghostbusters where he asked participants to guess which of a series of symbols was printed on a concealed card). The meta-analyses indicate consistently small but significant effects (around .02) – that is, participants were able to detect the correct answer better than if they had been guessing.

Related, but new to me, are so-called "hidden reward" experiments. In one example, participants choose from an array of kanji characters (Japanese writing using Chinese letters) the one they prefer aesthetically, unaware that choosing a certain character will produce benefits for their partner in another room. Cardeña cites a review that suggestst participants tend towards the characters that help out their partner.

These forced-choice approaches are still used, but the psi research community has turned more enthusiasm towards a free-response technique called the "Ganzfeld procedure". Blindfolded participants in a soundproofed room say what comes into their mind in an attempt to describe a film clip that they have not seen (they are either shown it later, or it may be playing simultaneously in another location). If judges can use these descriptions to pick between this clip and other distractor clips, this is used as evidence that the participant detected information about the clip without using their physical senses. Meta-analyses of the field suggest a statistically significant effect of about .14 to .15. Some critics have suggested that the effect size goes down when lower quality studies are excluded, but others contend that the opposite is true, with the best studies showing the strongest evidence. Either way, the effects are strikingly larger for selected participants – those who were familiar with the studies or who were chosen because they had traits previously associated with stronger psi effects, such self-efficacy, extraversion and openness-to-experience.

A similar pattern is found in remote viewing, an analogous procedure where a sender attempts to provide information about where they are to a participant located elsewhere. 

Similar to Bem's controversial "Feeling the Future" experiments, Cardeña also reviews findings from "presentiment studies", where effects are looked for prior to an event, such as skin conductance changes before seeing emotionally-charged images. Here there is a significant effect size across 26 data sets, with the higher quality studies having larger effects than the lower quality ones.

Another field of psi research considers psychokinesis, which is mental action altering physical objects without the "normal" mechanism of thought affecting the body first. This is typically investigated using subtle changes, such as influencing the fall of a dice or perturbing the action of a random number generator. While meta-analyses suggest significant effects, these are generally flimsier than those in the area of anomalous cognition: smaller and less robust – for example, some show clusters of significant findings near p=.05, which researchers now use as a marker of questionable research practices. The research into non-contact healing effects also suffers from these criticisms and is additionally hard to shield from potential placebo influences.

Cardeña concludes that "overall the meta-analyses have been supportive of the psi hypothesis" (i.e. indicating that anomalous effects are real), with the strongest findings for free-response experiments on anomalous cognition like the Ganzfeld work, and weaker for forced-choice designs and work in the psychokinesis sub-field. On this basis, it is arguable that, as much as any other field of psychology, there is at least something meriting investigation. 

But psi isn't any other field of psychology. Because of its claims, it is understandably held to high standards and many dismiss the findings as being due to poor quality methods. In fact this scrutiny has forced psi research to be ahead of the game on many research practices. It pioneered randomisation with masking (concealing group allocation from participants and researchers, to reduce bias); produced some of the earliest meta-analytical work; and has been preregistering studies for over forty years. Cardeña also argues that, rare for psychology, this is a field in which non-replications are incentivised.

However, even if there is solid supporting evidence, sceptics allege the endeavour is fundamentally ascientific because there are no mechanisms or models to understand the putative effects. To address this criticism, Cardeña lays out the model most psi researchers ground their work in, which centres on three concepts well-established in physics. The first is "non-locality" – while science tends to focus on demonstrating direct cause and effect – one billiard ball striking another – quantum mechanics (QM) shows evidence of "spooky" action at a distance, raising the possibility that all things are in some way fundamentally entangled. 

The second idea is that objects are in themselves not fully determined, but remain as probability functions until they are measured by a sentient observer.  

The third idea relates to the post-Einsteinian notion that events in the future of a slow-moving individual may have already happened to a faster moving one. Some theories account for such issues by positing that all times co-exist simultaneously. Cardeña gives the example that measuring the spin of a particle appears "to retroactively determine the spin of a delayed photon entangled with it." 

These three ideas add up to an interpretation in which objective matter and subjective perspective are not firmly separate, but interlace, where reality may be (mostly) experienced in a sequential temporal fashion but is in some sense simultaneous or eternal. These ideas are absent from certain influential modern world views such as Marxism and positivism, and they understandably clash with the causal metaphors that most people – especially the scientifically minded – use to organise their experience. But it's worth remembering that they are preeminent historically in almost every philosophical and folk tradition across the world, including tallying with idealism, in which mind is primary to the material (idealism can also accommodate counterintuitive takes on time). 

 But yet another criticism is that if psi effects are real, why aren't we all Professor Xs with amazing telepathy and why are the effects so small? Well, the fact that something exists doesn't mean it needs to operate like in the movies. It makes sense for our fragile bodies to be organised to mainly respond to sensory and bodily stimuli – hearing or seeing something new or threatening should always win in the battle for attention, potentially masking psi effects most of the time. 

The small effects found in studies may also reflect the fact that the stakes are especially low – far lower than the situations in which people spontaneously report such experiences, such as around the sudden sickness or death of a loved one. The effect sizes also reflect the average of all people, and the studies seem to show that subsets of individuals are more receptive to psi experiences, producing much higher effects when they alone are tested.  Cardeña also points out that some of the psi meta-analysis effect sizes approach those found in social psychology research, and are larger than for some evidence-based practices such as using aspirin for heart conditions.

Cardeña concludes that psi has vertical and horizontal support: "vertical" meaning that different protocols have provided consistent effects over years or decades of investigation, even as protocols have become more rigorous; and "horizontal" meaning a pattern of results across different areas (e.g. similar profiles of people who perform better at tasks). According to researcher Dean Radin, findings from parapsychology suggest "that there is some way that humans are connected with the rest of reality in non-local ways." Should psychology and funding bodies be paying more attention? 

Further reading

—The experimental evidence for parapsychological phenomena: A review

About the author

Alex Fradera (@alexfradera) is Staff Writer at BPS Research Digest