Darwin from Descent of Man to Emotions under Domestication" which went on sale on 30 January 1868. He now published his ideas on human evolution and on how beautiful but apparently impractical features could have evolved in "The Descent of Man, and Selection in Relation to Sex". After revising "The Origin of Species" as the definitive 6th edition, his major works on species culminated in "The Expression of the Emotions in Man and Animals". This period was followed by extensive work on insectivorous plants and research into worms. Despite Darwin's concerns that his children were weakened as his wife Emma Darwin was his cousin or had inherited
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