Although it is often assumed that men have an important influence on their children's development, the supportive evidence can be difficult to locate and summarize. In this paper, we analyse the evidence with respect to four emergent themes. First, men often appear to interact with their children less sensitively than mothers do, and many children thus appear to form closer attachments to their mothers than to their fathers. Second, the data also indicate that fathers may play specific and important roles, with men in some cultures having clearly defined roles as playmates to their children. Third, paternal play styles predict later socio-emotional development while paternal involvement seems to predict adult adjustment better than maternal involvement does. Such evidence suggests, fourth, that we need appropriate measures of fatherhood that are not simply borrowed from the study of motherhood.