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 with livestock breeders and pigeon fanciers; on observations on his infant son William Erasmus Darwin ("A Biographical Sketch of an Infant" - published as a paper in the philosophical journal "Mind"), on his family's dogs and cats, and on the orangutans at London Zoo; on simple psychology experiments with members of his family concerning the recognition of emotional expression; on the neurological insights of Duchenne de Boulogne, a physician at the Salpêtrière asylum in Paris; on hundreds of photographs of actors, babies and children; and on descriptions of psychiatric patients in the West Riding Pauper Lunatic Asylum at Wakefield in