Emotion theory
The four most common emotions on theorists' lists, and the basic states of Commedia dell'arte, are fear (or terror, shock, surprise), anger (or rage), sorrow (or sadness), and joy (happiness, glee).Robert Plutchik developed his psychoevolutionary theory of basic emotions in 1980, with ten postulates, and eight basic emotions: fear, anger, sorrow, joy, and disgust, acceptance, anticipation, and surprise. Inclusion is based on relevance to adaptive biological processes (i.e. evolution).
External Links
http://www.personalityresearch.org/basicemotions/plutchik.html