The Expression of the Emotions in Man and Animals allows cultural factors only an auxiliary role in the shaping of expression. This biological emphasis leads to an appreciation of the universal nature of expression, with its implication of a single origin for the entire human species; and Darwin points to the significance of emotional communication with children in their psychological development. Darwin sought out the opinions of some leading British psychiatrists, notably James Crichton-Browne, in the preparation of the book which forms his main contribution to psychology. Amongst the innovations with this book are Darwin's circulation of a questionnaire (probably inspired by his cousin, Francis Galton) in his preparatory
The Expression of the Emotions in Man and Animals with "ill-temper", sulkiness and determination), Chapter 10 on hatred and anger, Chapter 11 on "disdain, contempt, disgust, guilt, pride, helplessness, patience and affirmation" and Chapter 12 on "surprise, astonishment, fear and horror". In his discussion of the emotion of disgust, Darwin notes its close links with the sense of smell, and conjectures an association with excretory products. In Chapter 13, Darwin discusses complex emotional states including self-attention, shame, shyness, modesty and blushing. Darwin describes blushing as "the most peculiar and most human of the expressions". Darwin closes the book with Chapter 14 in which he recapitulates his main argument: he