Fingers in the Mouth Morris’s explanation of this gesture is that the fingers are placed in the mouth when a person is under pressure. It is an unconscious attempt by the person to revert to the security of the child sucking on his mother’s breast. The young child substitutes his thumb for the breast and as an adult, he not only puts his fingers to his mouth but inserts such things as cigarettes, pipes, pens and the like into it. Whereas most hand-to-mouth gestures involve lying or deception, the fingers-in-mouth gesture is an outward manifestation of an inner need for.
