For years, <em>What the Face Reveals</em> has been a singular collection of previously published original research using the Facial Action Coding System (FACS) to study facial behavior. Accompanying each article is an author commentary, prepared for this book, on the value of bringing FACS-based measurement to their area of study. The new third edition includes new research findings and applications, and extends the focus of earlier volumes to showcase the development of Animal FACS systems and applications of automated FACS measurement. <em>What the Face Reveals</em> is an indispensable reference to anyone who uses FACS in their research, as the studies showcased here employ a variety of methodological and design technique for the use of FACS that could be replicated or extended in other research contexts. New to this Edition: --Revised to include 50% new contributions, reflecting changes in facial measurement in the 21st century --New structure organized around six areas of FACS research: Animal FACS, Automated Measurement, Basic Affective Science, Development, Pain, Psychopathology, and Social and Health Psychology