The Experimental Evidence for Parapsychological Phenomena: A Review
Etzel Cardeña
(published in American Psychologist, 2018, Vol.73, No. 5, 663-677)
Author :
Etzel Cardeña is Thorsen Professor of Psychology at Lund University in Sweden, where he directs CERCAP, the Center for Consciousness on Research and Anomalous Psychology. His main areas of research include anomalous experiences (including ostensible psi phenomena), hypnotic neurophenomenology, and dissociative reactions to trauma and dissociative disorders. He has been a Fellow of APA and APS, among others, and President of three professional organizations. His close to 300 professional publications include the books Varieties of Anomalous Experience, and Altering Consciousness, Volumes 1 and 2.
Link to University website of Prof. Cardeña
Summary:
In his paper Cardeña gives a general introduction into psi, which he divides into 2 major areas:
1) extrasensory perception (ESP) - including
- telepathy (being affected by other people's thoughts)
- clearvoyance (optaining information at a distance) includes remote viewing
- precognition/presentiment (being affected by a future event)
- retrocognition (having noninferable knowledge about a past event)
2) psychokinesis (PK) - including
- putative direct action of mental events (intent) on physical objects
- PK is devided into 2 subgroups:
- macro-PK (anomalous force) - observable events e.g. table levitation
- micro-PK (anomalous pertubation) - unobservable events e.g. influencing a random number generator
Cardeña continues with an analysis on how the notion that psi phenomena violate the laws of nature and that they invalidate scientific achievements might both be misperceptions. He points towards the nonlocal interpretation of quantum mechanics as one option to explain psi effects. He also points towards hyperdimensional approaches within physics where a hyperdimensional "transcendetal field" could provide a framework to explain certain psi effects. From an evolutionary perspective psi abilities could even be interpreted as a fitness advantage as they could nudge us towards making better choices.
The meta-analysis of psi is at the core of Cardeña's paper. In this segement he summarizes about 1700 psi experiments conducted at over 40 universities around the world.
For those readers not familiar with statistics a very short insert: One commonly uses statistics measure used in psychology is the level of statistical significance. In order to interprete these p-values you just have to understand that the smaller the p-value the more significant the result. Often a 5% value (= 0.05) is used as the limit and any values below 0.05 are considered as signifiant. Whenever you see values with a negative exponent e.g. 10⁻³ this is equivalent to a value of 0.001 so the negative exponent basically tells you the amount of zeros in the value. The higher the negative exponent the smaller the value and the higher the significance of the effect.
Here is a condensed summary of how significant each psi effect was based on Cardeña's meta-analysis:
Anomalous cognition (receiving information / guessing a randomly chosen target)
- Telepathy (Storm,2010): 10⁻16
- Precognition (Bem,2015): 10⁻10
- Psi dreams studies (Storm,2017): 10⁻7
- Remote Viewing (Milton,1997): 10⁻9
- Presentiment (Mossbridge,2012): 10⁻8
- Precognition (Baptista,2015): 10⁻25
Anomalous perturbation (sending information / mentally influencing people/objects)
- Direct mental interaction in living systems (Schmidt,2015): 10⁻3
- Remote Healing (Roe,2015): <.05
- Influencing dice (Radin,1991): 10⁻3
- Random Number Generators / Micro-PK (Bösch,2006): <.05
- Global Consciousness Project (Nelson,2015): 10⁻13
As you can see, all reported forms of psi phenomena are significant based on this statistical analysis but the level of significance varies. Phenomena related to anomalous cognition are way more significant than those related to anomalous pertubation. You find references to all these individual meta-analysis for each subject in the paper in case you want to look into them in more detail.
In the discussion of his results Cardeña addresses several common criticisms of psi experiments:
1) Problems with reliable replication of results
On this subject Cardeña points out that psi phenomena can not be replicated "on demand". But also replication studies on non-psi subjects have the same issue as shown by the "Many Labs" project, where 36 independant laboratories tried to replicate 16 psychological studies published in top journals. Only 34% of the results were confirming the original studies. So demanding a 100% replication rate for psi experiments is not really fair.
2) The measured effect sizes are very small
On this subject Cardeña points out that the effect sizes of psi phenomena might be small but that a meta-analysis of 25.000 non-psi psychology experiments also only reported an average effect size similar to those in Cardeña's psi meta-analysis. The effects of e.g. aspirin or propanolol to prevent heart conditions are much smaller than those of psi phenomena but are clinically recommended.
3) Significant psi effects only show in low-quality experiments
On this subject Cardeña points out that most meta-analysis which he considered for his paper did control for quality and that e.g. the presentiment meta-analysis showed that studies with higher quality standards showed higher and not lower effects. He also points out that psi studies have been done under more rigorous procedures than mainstream psychology studies and that the mainstream has adopted these procedures lateron. Another problem is selected publishing: While skeptics claim psi researchers would not publish failures where psi effects did not show as expected, a meta-analysis actually showed that skeptics do just that with their own psi research when trying to disprove psi effects they tend to publish failures and not publish experiments where psi effects were documented.
Cardeña summarizes his meta-analysis as follows: "The evidence provides cumulative support for the reality of psi, which cannot be readily explained away by the quality fo the studies, fraud, selective reporting, experimental or analytical incompetence or other frequent criticisms. The evidence for psi is comparable to that for established phenomena in psychology and other diciplines..."
Download: https://seriouspod.com/wp-content/uploads/2018/07/PSI-American-Psychologist.pdf
Additional information:
In 2014 Prof. Cardeña wrote a petition that calls for a thorough investiation of PSI phenomena and anomalies of consciousness. This pedition was signed by 90 scientist, most of the professors at renowed universities all over the world.
Link to article containing his petition and the names of all 90 scientist
