• Meltzoff and Moore (1977)

• • a well-known systematic study of interactional synchrony between caregivers and infants
• • An adult model displayed one of three facial expressions and hand gestures
• • Initially, a dummy (pacifier) was placed into the infant's mouth to prevent any facial responses
• • The dummy was then removed and the infant's facial expressions were recorded on video and observations were noted by an independent observer
• • They found that interactional synchrony began as young as two weeks old when infants could mirror the facial expressions and hand gestures of an adult