Scientists who study anomalistic psychology consider mediumship to be the result of fraud and psychological factors. Research from psychology for over a hundred years suggests that where there is not fraud, mediumship and Spiritualist practices can be explained by hypnotism, magical thinking and suggestion.[41][42] Trance mediumship, which according to Spiritualists is caused by discarnate spirits speaking through the medium, can be explained by dissociative identity disorder.[43] 

Some scientists of the period who investigated spiritualism also became converts. They included chemist Robert Hare, physicist William Crookes (1832–1919) and evolutionary biologist Alfred Russel Wallace (1823–1913).[13][14] Nobel laureate Pierre Curie took a very serious scientific interest in the work of medium Eusapia Palladino.[15] Other prominent adherents included journalist and pacifist William T. Stead (1849–1912)[16] and physician and author Arthur Conan Doyle (1859–1930).[17]