Automatic writing as a spiritual practice was reported by Hyppolyte Taine in the preface to the third edition of his De l'intelligence, published in 1878. Besides "etherial visions" or "magnetic auras", Fernando Pessoa claimed to have experienced automatic writing. He said he felt "owned by something else", sometimes feeling a sensation in the right arm that he claimed was lifted into the air without his will. Georgie Hyde-Lees, the wife of William Butler Yeats, also claimed that she could write automatically. Sri Aurobindo as well as The Mother (Mirra Alfasa) regularly practiced Automatic writing.
William Fletcher Barrett wrote that "Automatic messages may take place either by the writer passively holding a pencil on a sheet of paper, or by the planchette, or by a 'ouija board'." In spiritualism, spirits are claimed to take control of the hand of a medium to write messages, letters, and even entire books. Automatic writing can happen in a trance or waking state. Arthur Conan Doyle, in his book The New Revelation (1918), wrote that automatic writing occurs either by the writer's subconscious or by external spirits operating through the writer. The Surrealist poet Robert Desnos claimed he was among the most gifted in automatic writing. Some psychical researchers such as Thomson Jay Hudson have claimed that no spirits are involved in automatic writing and that the subconscious mind is the explanation.
Alleged cases of automatic writing have included Aleister Crowley, Jane Roberts, Helen Schucman and Neale Donald Walsch. In 1975, Wendy Hart of Maidenhead claimed that she wrote automatically about Nicholas Moore, a sea captain who died in 1642.
Scientists and skeptics consider automatic writing to be the result of the ideomotor effect.
Psychology professor Théodore Flournoy investigated the claim by 19th-century medium Hélène Smith (Catherine Müller) that she did automatic writing to convey messages from Mars in Martian language. Flournoy concluded that her "Martian" language had a strong resemblance to Ms. Smith's native language of French and that her automatic writing was "romances of the subliminal imagination, derived largely from forgotten sources (for example, books read as a child)". He invented the term cryptomnesia to describe this phenomenon.
Physician Charles Arthur Mercier in the British Medical Journal (1894) criticized the spiritualist interpretation of automatic writing, concluding, "there is no need nor room for the agency of spirits, and the invocation of such agency is the sign of a mind not merely unscientific, but uninformed". In 1927, psychiatrist Harold Dearden wrote that automatic writing is a psychological method of "tapping" the unconscious mind and there is nothing mysterious about it.
According to skeptical investigator Joe Nickell, "automatic writing is produced while one is in a dissociated state. It is a form of motor automatism, or unconscious muscular activity."
Neurologist Terence Hines has written that "automatic writing is an example of a milder form of dissociative state".
Automatic writing behaviour was discovered in three patients with right hemispheric damage