The body movement and visual behavior of women and men engaged in mixed-sex dyadic interactions were analyzed in a three-factorial design including the personal factor sex of the interactants, the situational factor partner familiarity, and the situational factor visual attention of the interaction partner. Measures of nonverbal activity were derived from integrated time-series protocols of body movement and gaze for both interaction partners. Data analysis revealed significant sex differences in individual frequency and duration of movement and gaze, as well as dyadic differences for both behavior measures. Men, in general, were more active while women were more visually attentive. Also, the results point to specific interaction effects between sex and familiarity. The data indicate that there were specific adaptational strategies for both sexes with familiar and unfamiliar partners.