The Expression of the Emotions in Man and Animals Darwin notes the universal nature of expressions in the book, writing: "the young and the old of widely different races, both with man and animals, express the same state of mind by the same movements." This connection of mental states to the neurological organization of movement (as the words "motive" and "emotion" suggest) is central to Darwin's understanding of emotion. Darwin himself displayed many biographical links between his psychological life and locomotion, taking long, solitary walks around Shrewsbury after his mother's death in 1817, in his seashore rambles near Edinburgh with the Lamarckian evolutionist Robert Edmond Grant in 1826/1827, 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,