The rod-and-frame effect as a function of the righting of the frame.

Several experiments investigated the theory that there is a tendency to interpret the axes of a large tilted frame of reference as surrogates of the main axes of the environment. Therefore there is a tendency to perceive such a frame as either upright or as less tilted thanit is--righting-- and, accordingly, to perceive a vertical rod as tilted in the opposite direction--the rod-and-frame effect (RFE). A high correlation was found between righting and the RFE in all experiments. When a double frame apparatus was used, with the outer frame upright and the inner frame tilted, there was no consistent RFE. This condition eliminates any righting effect. When the outer frame was tilted and the inner one was upright, however, the RFE was induced, as was a correlated righting effect. All experiments were repeated with the subject's head tilted, thereby increasing the tendency toward righting of the frame. The result was a corresponding increase in the RFE. The RFE can thus be thought of as the solution to the problem of the rod's tilt given the perceived tilt of the frame.U