Asymmetries in Affective Facial Expression: Behavior and Anatomy
|Joan C. Borod*|
|Aphasia Research Center and Boston University School of Medicine|
|Wellesley College and Aphasia Research Center|
Everyday experience and scientific study suggest that the face is a primary organ for communication and emotional expression. It is well known that of all the animals, the human being has the most extensively developed facial musculature and depends heavily on facial behavior as a facilitator of social interaction ( Roberts, 1966). Historically, the psychologist was preceded in the study of facial expression by the anatomist, the painter, and the actor. Sir Charles Bell, a nineteenth-century anatomist, was one of the first to underline the significance of anatomy for the painter and the importance of facial musculature for the actor ( Woodworth & Schlosberg, 1954). By the end of that century, Charles Darwin ( 1890) had described in some detail the facial expressions associated with what he considered to be the fundamental and universal emotions (fear, rage, laughter, crying, disgust, and surprise) and argued that emotions were functional products of evolution. Although Darwin believed that emotional expressions were direct reflections of bodily conditions, others ( Landis, 1924) suggested that some emotional expressions, for example, affection, scorn, were more subtle and more likely to have been influenced by the social environment (i.e., learned).
Impressed by the observation that the two sides of the human face demonstrate striking asymmetries for extent of movement and intensity of expression, a number of investigators have begun to focus on the meaning of these asymmetries. Given that each side of the face, and in particular the lower portion, is believed to be innervated predominantly by the contralateral cerebral hemisphere____________________