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
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