The Expression of the Emotions in Man and Animals typically accompanies blushing. A German translation of "The Expression" appeared in 1872; Dutch and French versions followed in 1873 and 1874. A second edition of the book, with only minor alterations, was published in 1890. Before Darwin, human emotional life had posed problems to the western philosophical categories of "mind" and "body". Darwin's interest can be traced to his time as a medical student and the 1824 reprint of Sir Charles Bell's "Anatomy and Philosophy of Expression" which argued for a spiritual dimension to the subject. In contrast, Darwin's biological approach links mental states to the coordination of movement, and
The Expression of the Emotions in Man and Animals shows how human emotions link mental states with bodily movement, and are genetically determined, deriving from purposeful animal actions. He comments on the implications of the book: a single origin for the entire human species, with universal human expressions; and he stresses the social value of expression, citing the emotional communication between mother and child. This was one of the first books to be illustrated with photographs – with seven heliotype plates – and the publisher John Murray warned that this "would poke a [terrible] hole in the profits". The published book assembled illustrations rather like a Victorian family album,