James W. Pennebaker The University of Texas at Austin At first glance, a scientific book on the face doesn't make a great deal of sense. After all, the face is not a biological unit that falls into a specific medical specialty. By the same token, it is not part of a of a specific clear functional system that falls within the purview subdiscipline of psychology, philosophy, sociology, or any other traditional area. It seems that the only organizing principle of the face is that all humans have one and that it is central to the experience of being human. As a social stimulus, the face can signal emotions, personality, sex, physical and mental health, social status, age, and aspects of our thoughts, intentions, and our inner selves. At various points in our lives, we spend a tremendous amount of time and money for cosmetics, cleansers, medicines, and, occasionally, surgery to enhance our face. In the same way that a normative, symmetrical face can attract praise and even adoration, damage to the face through birth defects, disease, or injury is almost always stigmatizing. Our faces, then, are social advertisements for who we are.