This subarticle describes some of the experimental results and interpretations claimed by some parapsychologists today. Rather than insert the words "purported" or "supposed" or "claimed" in every sentence and paragraph of the this section, which would make for overly cumbersome reading, these claims are presented here in straightforward language. As such, the reader is advised that all of these claims are hotly disputed within the scientific community (see the section on Controversy in the main article), and the Wikipedia takes no position regarding the veracity of these claims.
Though some parapsychologists still pursue the study of "macro" or large scale phenomena, such as spoon bending and events of the type reported from the era of the spiritualist mediums, these have not been well-established experimentally from the point of view of most parapsychologists. The strongest experimental evidence of psi phenomena have been of smaller-scale phenomena, such as telepathy, event guessing (e.g. card-guessing experiments and their offspring), and "micro" psychokinesis experiments such as influencing random-event generators. In these experiments the effects are typically visible only with statistical analyses. In this sense, the observed effects are small compared to the anecdotal macro phenomena. However, these effects are not small when compared to statisticaly measured events in many fields of science outside of parapsychology.
In his book The Conscious Universe, Dean Radin reviews statistical meta-analyses of psi experiments in several different categories with the following overall results, where the 95% confidence interval excludes chance in all analyses:
- Clairvoyance and telepathy experiments: several categories of experiments ranging from ESP card tests, to dream and ganzfeld telepathy studies, to remote viewing and PEAR precognitive remote perception studies, all normalized for chance hit rate of 50%, the categories range from about 54% to 67% hit rate, averaging about 60%.
- Psychokinesis experiments:
- Dice tossing: 51.2% hit rate (vs. chance = 50%) over 148 experiments from 1935 to 1987, involving thousands of participants and millions of tosses.
- Random Number Generator (RNG) studies: 51% hit rate (vs. chance = 50%) over 832 studies from 1959 to 1987 (1989 analysis).
- Distant mental influence on human electrodermal activity: 53% (vs. chance = 50%), over 400 sessions as of 1997.
- Feeling of being stared at: 63% (vs. chance = 50%) over studies from 1913 to 1996.
There are many theories or models being offered within parapsychology to account for various aspects of psi phenomena, though there is no widely accepted comprehensive theory that accounts for all phenomena. Some of the observations and conclusions based on experiments include the following:
- Psi ability seems to be latent in all human beings, though there does appear to be a non-uniform distribution of talent. Some individuals can apparently improve their psi abilities through training, though apparently there are different limits or capacities among individuals. The analogy is that most people can learn to ride a bicycle or play an instrument, though few will ever compete in the Tour de France or play in Carnegie Hall.
- Psi phenomena do not appear to be impeded by physical or electro-magnetic shielding, such as faraday cages or several hundred feet of water, nor do they appear to diminish in strength or intensity over distances of thousands of kilometers. This would appear to discount an electro-magnetic basis for the phenomena.
- Psi phenomena do not appear to be time-bound according to our common notions of causality. Precognition and presentiment experiments suggest abilities to perceive events in the (near) future. The PK experiments of Helmut Schmidt and others suggest abilities to affect events in the past, while some of the PEAR studies suggest ability to affect events in the future.
- There are as yet no experiments to test for telepathy which can rule out the more general clairvoyance in accounting for positive results. Similarly there are other psi experiments which allow for more than one type of psi phenomenon to account for positive results.
