EXPRESSION OF THE EMOTIONS, the facial and other bodily changes which are the characteristic accompaniments of Emotion (q.v.). According to Darwin (in Expression of the Emotions) these expressions are survivals of actions which were once useful under conditions which induce the emotions. They are "serviceable associated habits." As this theory does not appear to account for all cases, it has been supplemented by various auxil iary hypotheses, of which the following are the most important. Experiences which induce like emotions express themselves in the same way, namely, in the once useful way of one of them. On the other hand, experiences which excite opposite emotions express themselves in opposite ways, assuming that one of them has an expression that was once useful. Some psychologists explain the expression of the emotions as a "direct nervous discharge" result ing in muscular activity; pleasurable emotions causing an increase in muscular activity, while painful ones inhibit it.
See FEELING, PSYCHOLOGY OF ; JAMES-LANGE THEORY OF EMOTIONS.