Emotional expression propose that emotions are constructed based upon the person, situation, culture, and past experiences, and that there are no preset emotional responses that are consistent and specific to one emotion or another. The basic model of emotions finds its roots in Charles Darwin's "The Expression of Emotions in Man and Animals". Darwin claimed that the expression of emotions involves many systems: facial expression, behavioral response, and physical responses, which include physiological, postural, and vocal changes. Most importantly, Darwin claimed that emotional expression was consistent with his theories on evolution and thus, the expression of emotion is universal and should therefore
The Expression of the Emotions in Man and Animals with engravings of the Darwin family's domestic pets by the zoological illustrator T. W. Wood as well as work by the artists Briton Rivière, Joseph Wolf and A.D. May. It also included portraits by the Swedish photographer Oscar Rejlander (1813–1875), anatomical diagrams by Sir Charles Bell (1774–1842) and Friedrich Henle (1809–1885), as well as illustrational quotations from the "Mécanisme de la physionomie humaine" (1862) by the French neurologist Duchenne de Boulogne (1806–1875). As a result of his domestic psychology experiments, Darwin reduced the number of commonly observed emotions from Duchenne's calculation of more than sixty facial expressions, to just six