The significance of the human face in social interaction can hardly be overestimated. We rely primarily on facial appearance in discriminating between members of our species, but we also use the face to judge the age and gender of a person and to interpret his or her emotional state. We find certain faces pleasant or attractive, attribute personality characteristics to people such as intelligence or honesty based on physiognomy, and use facial cues to guess people's intentions and predict their behavior toward us. Similarly, we can gauge the effect of our words or actions on others by the feedback we receive from their faces. The face assumes a privileged role in social communication almost immediately after birth, suggesting that the neural systems underlying various facial behaviors are to a large extent innately specified and genetically determined.