In short, hypnosis research is beset with the same problem concerning experimenter effects that has restricted progress in parapsychology (Parker & Millar, 2014).
Yet there seems to be an experimenter effect here: Not all researchers have found this to be the case (Nadon, Hoyt, Register, & Kihlstrom, 1991).
Although experimenter effects were observed for task performance, there was no evidence that the behavior or attire of the experimenter influenced cardiovascular or self-reported distress responses during task completion.
There is only a small body of literature examining experimenter effects on physiological responses to mental stress (Chapman et al.
If we are going to penetrate the issue of experimenter effects at a deeper level, we need to discuss the basic theoretical issue about the nature of psi: Are we dealing with purely quantum-level statistical effects, the type of observer feedback that forms a basis for observational theory, or something more, requiring that psychological factors are a decisive influence.
This approach, which we might identify as the "British School," emphasizes the social interaction theory of experimenter effects.
To conclude, although it is recognized that experimenter effects may influence parapsychological results, it should now be seen that their occurrence in the field is not unique.
Experimenter effects in scientific research: How widely are they neglected?
One of the main predictions of goal-oriented psi experimenter effects
is that z will be unrelated to sample size on experiments (Kennedy, 1994, 1995).
Even Wiseman, who is famous (some might say infamous) for his categorical statements of never having encountered any evidence of the paranormal, was one of the joint authors of the security setup for the successful ganzfeld experiment with Kathy Dalton (Dalton, Morris, Delanoy, Radin, Taylor, & Wiseman, 1996) and succeeded with Marilyn Schlitz (Schlitz, Wiseman, Watt, & Radin, 2006) in replicating their experimenter effect
findings in two of three studies.
Wiseman and Schlitz (1997) examined the experimenter effect
by conducting a joint study in which a skeptic and a proponent acted as experimenters for two sets of trials.
The emerging model that seems most consistent with available data is that impressive psi is associated with the motivations of certain, selected individuals and operates in a goal-oriented manner, usually as experimenter effects
(Kennedy, 5004), but then consciousness or other factors separate from the person's identifiable motivations come into play and inhibit or sabotage the psi effects.
There may have been a unique experimenter effect
in the individual ("non-market") setting.
Therefore, the influence of a possible parapsychological experimenter effect
is unknown in this study.
Will there be an experimenter effect
on participants' finger-reading performance?