The Expression of the Emotions in Man and Animals Man and Animals", a collection of 37 papers with current research on the subject. Free e-book versions: The Expression of the Emotions in Man and Animals The Expression of the Emotions in Man and Animals is Charles Darwin's third major work of evolutionary theory, following "On the Origin of Species" (1859) and "The Descent of Man" (1871). Originally intended as a section of "The Descent of Man", it was published separately in 1872 and concerns the biological aspects of emotional life. In this book, Darwin sets out some early ideas about behavioural genetics, and explores the animal origins of such
The Descent of Man, and Selection in Relation to Sex to the forces of sexual selection. While debates on the subject continues, in January 1871 Darwin started on another book, using left over material on emotional expressions, which became "The Expression of the Emotions in Man and Animals". In recent years controversy also involved the peacock tail, the most famous symbol of the principle of sexual selection. A seven-year Japanese study of free-ranging peafowl came to the conclusion that female peafowl do not select mates merely on the basis of their trains. Mariko Takahashi found no evidence that peahens expressed any preference for peacocks with more elaborate trains, such as