Introduction The aim of the present longitudinal and naturalistic study was to investigate the facial expressions of emotions of infants and fathers during spontaneous dyadic "protoconversation" and the preceding/following pauses, in the course of early infancy . This is important because it will extend our understanding on the way infants, without being able to speak, begin communication and develop a capacity to share understanding of what they and fathers mean through their behavioural expression (Trevarthen, 1993a, 1993b).