If you have a fear of heights, this effect may be quite familiar to you. When you look over a ledge from a great height, you almost feel a pull as if some invisible force were causing you to be unsteady precisely when you wish that would not happen. If we can generalize from the literature on suppression, this effect is probably not just in your mind: your fear activates some of the muscles that move you toward the ledge, as well as those that move you away from it. As a result, you feel unsteady.
