Body, face, and voice: Nonverbal expression of emotion in infancy

Ever since the work of Charles Darwin, there has been scientific inquiry into the nonverbal expression of emotion. Especially in the past 25 years, evidence for specific constellations of emotional signals has been accumulating. Whereas patterns of facial expression of many basic emotions have been well established, there is insufficient objective research into the vocal and body movement signals of the fundamental affect states. The study hypothesized that there are specific combinations of vocal and body movement signals that co-exist with facial expression constellations. Eighty segments of 13-month old infants displaying facial expressions of joy, interest, sadness, or anger were coded for the simultaneously occurring vocal and body movement signals of emotion. Vocalization parameters including phrase length, volume, pitch range, and harmonic tone were found to distinguish the emotions. Body movement indicators of emotion included the changing of the body shape in space, and the quantity and quality of shifts in muscular tension. Conclusions support the differential emotions theory (Izard, 1972).Ph.D., Creative Arts in Therapy -- Drexel University, 199