Abstract: A system is provided for measuring psychological suggestibility components in which certain physical stimuli are applied to a subject's arm or other body part and the subject's reaction is detected. The arm is supported by three parallel bar members, the intermediate member being stationary and the two outside members being moved downwardly to suggest to the subject a downward movement of his arm. In addition, squeezing forces are applied through a flexible and stretchable element extending from one of the outside members over the arm to the other of the outside members. Also, pointed prongs are movable downwardly against the upper surface of the subject's arm to apply uncomfortable pressure thereto. The vertical position of the subject's arm and vertical movement thereof are indicated by lights energized from contact devices associated with certain of the prongs.