These studies conducted by Spanos led to the modern understanding that hypnosis is not an altered state and is actually suggested behaviors that the participant chooses to go along with or not.
[5][6] Along with this, Spanos conducted studies regarding dissociative identity disorder in which he stated that multiple personalities are not a product of trauma but are based on social norms.
Spanos worked for almost thirty years on this theory, first at the Medfield Foundation with Theodore X. Barber, John Chaves and others, and later at Carleton University in Canada.
[4] He argued that many of the actions performed under hypnosis can be simply explained by reference to social psychological and cognitive hypotheses (Spanos, 1996).
Spanos’ findings were to contribute to the view that the hypnotic state did not exist at all, and that the behaviors exhibited by those individuals are in fact due to their being “highly motivated”.
[9] He proposed that exhibiting multiple identities is a social role based upon the norms of a given culture, that it is an attention seeking behaviour reinforced by therapists through hypnosis, which Spanos describes as "highly reminiscent of Catholic exorcism procedures."
According to Spanos, hypnosis, spirit possession, and multiple personalities are similar phenomena that represent socially controlled behavior rather than special dissociative or trance states; like other social behaviors, they are learned through observation and interaction within a culture.
The sociocognitive explanation for dissociative identity disorder is accepted by some [10] but rejected by others who believe that multiple personalities result from severe trauma and cause a distinct psychological state, citing the fact that the majority of DID patients did not face hypnosis as part of their treatment and that phenomena like spirit possession and hypnosis have not been observed to cause essential diagnostic criteria such as amnesia.