Mentalist, illusionist and arch-skeptic Derren Brown here provides a spectacular display of the ideomotor phenomenon, whereby imagination and expectation influence subconscious muscular action.
Prepped by Brown’s dramatic stage management, his “subjects” begin to inadvertently and unevenly apply pressure to the table-top, causing it to shift and rock. As their emotional excitement at this seemingly supernatural phenomenon increases, and as they are exhorted to “follow” the table’s movements, their efforts become more cohesive while remaining involuntary, guiding the table around the floor in accordance with Brown’s subtle cues.
Almost identical “tests” were carried out in numerous 19th and early 20th century seance parlors, with the table’s apparently paranormal movement being taken as physical evidence of the presence of otherworldly spirits.