 Spencer’s explanation in his essay “On the Physiology of Laughter” (1911) is based on the idea that emotions take the physical form of nervous energy. Nervous energy, he says, “always tends to beget muscular motion, and when it rises to a certain intensity, always does beget it” (299). “Feeling passing a certain pitch habitually vents itself in bodily action” (302). When we are angry, for example, nervous energy produces small aggressive movements such as clenching our fists; and if the energy reaches a certain level, we attack the offending person. In fear, the energy produces small-scale movements in preparation for fleeing; and if the fear gets strong enough, we flee. The movements associated with emotions, then, discharge or release the built-up nervous energy. 