GESTURES have been described by Koehler and Goldstein as adaptive acts released by exterior situations. This definition is obviously too limited, since gestures also occur without outward provocation, solely as responses to imaginative situations. The most poignant proof of the latter type are the gestures of the insane. As the imagination has the same power as reality of unleashing expressive movements, it is of paramount interest to know if there is any difference between the psycho-motor reactions provoked by reality and those induced by fantasy. The faculty of imagining is linked with the emotional make-up. Even mental images of an objective type always have a pleasant or unpleasant character and are therefore tinged with emotion or feeling. I am particularly concerned to show the influence of the emotional images on gesture as these more than ‘ objective9 images are apt to reveal the fundamental nature of men.