The Expression of the Emotions in Man and Animals with his cousin Emma Wedgwood who held firm Christian beliefs. On 21 September 1838, Darwin recorded a confused and disturbing dream in which he was involved in a public execution where the corpse came to life and claimed to have faced death like a hero. In summary: Darwin put together the central features of his evolutionary theory at the same time that he was considering a scientific understanding of human behaviour and family life – and he was in some emotional turmoil. A discussion of the significance of Darwin's early notebooks can be found in Paul H. Barrett's "Metaphysics, Materialism
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