The Expression of the Emotions in Man and Animals is discussed in detail by Lucille Ritvo.John Bowlby makes extensive reference to Darwin's ideas in his presentations of attachment theory. Constitutional (psychosomatic) theories of personality were elaborated by Paul Schilder (1886 - 1940) with his notion of the body image, by the psychiatrist Ernst Kretschmer and in the (now largely discredited) somato-typology of W H Sheldon (1898 - 1977). The biology of the human emotions was further explored by Desmond Morris in his (richly illustrated) popular scientific book "Manwatching".In 2003, the New York Academy of Sciences published "Emotions Inside Out: 130 Years after Darwin's The Expression of the Emotions in
Body language postural expressions of emotions such as anger/aggression, happiness, and fear. These similarities support the evolution argument that social animals (including humans) have a natural ability to relay emotional signals with one another, a notion shared by several academics (Chevalier-Skolnikoff, 1974; Linnankoski, Laakso, Aulanko, & Leinonen, 1994). Where Darwin notes similarity in expression among animals and humans, the Cultural Equivalence Model notes similarity in expression across cultures in humans, even though they may be completely different. One of the strongest pieces of evidence that supports this model was a study conducted by Ekman and Friesen (1971), where members of a preliterate