Introduction

When people look at your face, what do they see? Do they merely notice your physical features, or can they read the emotions that you are experiencing? Ancient philosophers debated this issue, but during the past 150 years researchers have begun the scientific study of facial movements and the nonverbal messages they may convey.

Charles Darwin was an early theorist of the relation between emotions and facial expressions. He argued that human facial expressions have their evolutionary origins in specific animal behaviors. Thus the main types of facial expressions should be similar all around the world, and also should be recognizable by people in all cultures.