Emotion in animals specialised form of Occam's razor used in ethology, in which he stated: Charles Darwin initially planned to include a chapter on emotion in "The Descent of Man" but as his ideas progressed they expanded into a book, "The Expression of the Emotions in Man and Animals". Darwin proposed that emotions are adaptive and serve a communicative and motivational function, and he stated three principles that are useful in understanding emotional expression: First, "The Principle of Serviceable Habits" takes a Lamarckian stance by suggesting that emotional expressions that are useful will be passed on to the offspring. Second, "The Principle of
History of emotions historiographical approaches such as conceptual history, historical constructivism and the history of the body. Similar to the sociology of emotions or anthropology of emotions, the history of emotions is based on the assumption that not only the expression of feelings, but also the feelings themselves are learned. Culture and history are changing and so are feelings as well as their expression. The social relevance and potency of emotions is historically and culturally variable. In the view of many historians, emotion is, therefore, just as fundamental a category of history, as class, race or gender. A number of different methodological approaches