Hansel's most well-known work is his bookESP: A Scientific Evaluation (1966), revised (1980, 1989). In it, he examined the areas oftelepathy,clairvoyance,precognition, andpsychokinesis and analysed many majorESP experiments that claimed to have conclusively demonstrated the phenomenon. Hansel found that all of the research he examined suffered from poor experimental design, which allowed for error, misinterpretation, and fraud.[7] He suspected that the data from the Soal-Goldney experiments, run bySamuel Soal, was fraudulent but parapsychologists refused to accept Hansel's charge. However, Hansel was later proven to be correct.[8][9] Hansel noted that there was a history of "trickery" in psychical research[10] and reached the conclusion that although trickery was not necessarily the cause of the results, as long as it could not be ruled out ESP could not be claimed to have been conclusively demonstrated.[11][12] In his revised edition, Hansel (1980) points out that "after 100 years of research, not a single individual has been found who can demonstrate ESP to the satisfaction of independent investigators. For this reason alone it is unlikely that ESP exists".[13]
Hansel's book received positive reviews from scientists andsceptics.[15] The physicistVictor J. Stenger noted that "Hansel succeeded brilliantly in exposing the shoddiness of the experimental procedures ofRhine's laboratory."[16]Robert Sheaffer stated that Hansel's criticisms were devastating to the claims of ESP and the book was a severe challenge to parapsychology.[17] PhilosopherAntony Flew also gave a positive review, highlighting the failure of parapsychology to provide repeatable experiments.[18]
The work also received criticism, with parapsychologistJohn Beloff claiming the book was little more than an attempt to explain away the evidence.[19] Parapsychologist Gardner Murphy gave it a mixed-review but recommended the book "as valuable for the parapsychologist in pointing out ways in which he must tighten his research."[20] Hansel's revised edition in 1989 contained further studies and an appendix with replies to his critics.[21]
The psychologistDavid Marks in his bookThe Psychology of the Psychic (2000) noted that his discovery of an experimental error in parapsychological experiments confirmed the research of Hansel.[22]
"A Critical Review of the Experiments on Mr. Basil Shackleton and Mrs. Gloria Stewart as Sensitives".Proceedings of the Society for Psychical Research.53 (190). 1960.
"Experiments on Telepathy in Children: A Reply to Sir Cyril Burt".British Journal of Statistical Psychology.13 (2). 1960.doi:10.1111/j.2044-8317.1960.tb00055.x.
^Kurtz, Paul. (2001).Skepticism and Humanism: The New Paradigm. p. 51.ISBN0-7658-0051-9 "His book,ESP: A Scientific Evaluation was very influential in setting forth the skeptic's case against Soal, Rhine, and others. It was only in 1978, however, that Betty Markwick definitively showed that S. G. Soal had cheated in the Soal-Goldney tests and that random-number grading sheets, which he brought to the experiment and took back, were doctored. This scandal in parapsychology led to many people abandoning the field and becoming skeptics."
^Gardner, Martin. (2009).When You Were a Tadpole and I Was a Fish: And Other Speculations About This and That. Hill and Wang. p. 229.ISBN978-0-374-53241-3 "In spite of numerous accusations of fraud by C. E. M. Hansel and other skeptics, leading parapsychologists refused to believe the charges until Betty Markwick published her sensational findings in the Proceedings of the Society for Psychical Research."
