Editing Hypnosis (section)

== Susceptibility ==
{{Main|Hypnotic susceptibility}}
Braid made a rough distinction between different stages of hypnosis, which he termed the first and second conscious stage of hypnotism;<ref name="auto1">{{Cite book|url=https://books.google.com/books?id=Vs35STwQYQoC|title=The Discovery of Hypnosis: The Complete Writings of James Braid, the Father of Hypnotherapy|first=James|last=Braid|date=11 July 2008|publisher=UKCHH Ltd|isbn=9780956057006|via=Google Books|access-date=7 November 2015|archive-date=2 July 2023|archive-url=https://web.archive.org/web/20230702162805/https://books.google.com/books?id=Vs35STwQYQoC|url-status=live}}</ref> he later replaced this with a distinction between "sub-hypnotic", "full hypnotic", and "hypnotic coma" stages.<ref name="auto1"/> [[Jean-Martin Charcot]] made a similar distinction between stages which he named somnambulism, lethargy, and catalepsy. However, [[Ambroise-Auguste Liébeault]] and Hippolyte Bernheim introduced more complex hypnotic "depth" scales based on a combination of behavioural, physiological, and subjective responses, some of which were due to direct suggestion and some of which were not. In the first few decades of the 20th century, these early clinical "depth" scales were superseded by more sophisticated "hypnotic susceptibility" scales based on experimental research. The most influential were the Davis–Husband and Friedlander–Sarbin scales developed in the 1930s. [[André Muller Weitzenhoffer|André Weitzenhoffer]] and [[Ernest R. Hilgard]] developed the Stanford Scale of Hypnotic Susceptibility in 1959, consisting of 12 suggestion test items following a standardised hypnotic eye-fixation induction script, and this has become one of the most widely referenced research tools in the field of hypnosis. Soon after, in 1962, Ronald Shor and Emily Carota Orne developed a similar group scale called the Harvard Group Scale of Hypnotic Susceptibility (HGSHS).

Whereas the older "depth scales" tried to infer the level of "hypnotic trance" from supposed observable signs such as spontaneous amnesia, most subsequent scales have measured the degree of observed or self-evaluated ''responsiveness'' to specific suggestion tests such as direct suggestions of arm rigidity (catalepsy). The Stanford, Harvard, HIP, and most other susceptibility scales convert numbers into an assessment of a person's susceptibility as "high", "medium", or "low". Approximately 80% of the population are medium, 10% are high, and 10% are low. There is some controversy as to whether this is distributed on a "normal" bell-shaped curve or whether it is bi-modal with a small "blip" of people at the high end.<ref>{{cite journal | vauthors = Piccione C, Hilgard ER, Zimbardo PG | title = On the degree of stability of measured hypnotizability over a 25-year period | journal = Journal of Personality and Social Psychology | volume = 56 | issue = 2 | pages = 289–95 | date = February 1989 | pmid = 2926631 | doi = 10.1037/0022-3514.56.2.289 | citeseerx = 10.1.1.586.1971}}</ref> Hypnotisability scores are highly stable over a person's lifetime. Research by Deirdre Barrett has found that there are two distinct types of highly susceptible subjects, which she terms fantasisers and dissociaters. Fantasisers score high on absorption scales, find it easy to block out real-world stimuli without hypnosis, spend much time daydreaming, report imaginary companions as a child, and grew up with parents who encouraged imaginary play. Dissociaters often have a history of childhood abuse or other trauma, learned to escape into numbness, and to forget unpleasant events. Their association to "daydreaming" was often going blank rather than creating vividly recalled fantasies. Both score equally high on formal scales of hypnotic susceptibility.<ref>Barrett, Deirdre. Deep Trance Subjects: A Schema of Two Distinct Subgroups. in R. Kunzendorf (Ed.) Imagery: Recent Developments, NY: Plenum Press, 1991, pp. 101–12.</ref><ref>{{cite journal | vauthors = Barrett D | title = Fantasizers and dissociaters: data on two distinct subgroups of deep trance subjects | journal = Psychological Reports | volume = 71 | issue = 3 Pt 1 | pages = 1011–14 | date = December 1992 | pmid = 1454907 | doi = 10.2466/pr0.1992.71.3.1011 | s2cid = 44878822}}</ref><ref>Barrett, Deirdre. Fantasizers and Dissociaters: Two types of High Hypnotizables, Two Imagery Styles. in R. Kuzendorf, N. Spanos, & B. Wallace (Eds.) Hypnosis and Imagination, NY: Baywood, 1996 {{ISBN|0-89503-139-6}}</ref>

Individuals with [[dissociative identity disorder]] have the highest hypnotisability of any [[clinic]]al group, followed by those with [[post-traumatic stress disorder]].<ref>{{cite journal | vauthors = Spiegel D, Loewenstein RJ, Lewis-Fernández R, Sar V, Simeon D, Vermetten E, Cardeña E, Dell PF | title = Dissociative disorders in DSM-5 | journal = Depression and Anxiety | volume = 28 | issue = 9 | pages = 824–52 | date = September 2011 | pmid = 21910187 | doi = 10.1002/da.20874 | s2cid = 46518635 | url = http://dsm5.org/Documents/Anxiety,%20OC%20Spectrum,%20PTSD,%20and%20DD%20Group/PTSD%20and%20DD/Spiegel%20et%20al_Dissociative%20Disorders.pdf | archive-url = https://web.archive.org/web/20130501231851/http://dsm5.org/Documents/Anxiety%2C%20OC%20Spectrum%2C%20PTSD%2C%20and%20DD%20Group/PTSD%20and%20DD/Spiegel%20et%20al_Dissociative%20Disorders.pdf | df = dmy-all | url-status = dead | archive-date = 1 May 2013}}</ref>