TAUBER, MARGARET A. Sex Differences in Parent-Child Interaction Styles during a Free-Play Session. CHILD DEVELOPMENT, 1979, 50, 981-988. During the course of a longitudinal study, 145 children (average age 8%) were videotaped playing with a parent, most often the mother. Data coded from the videotapes were factor analyzed separately for parent and child, leading to 4 parent factors: sociable play, active play, buoyant support, and abrasive talk; and 4 child factors: active play, solitary play, buoyant mood, and physical contact seeking. Parents of girls were more likely to engage in sociable play, parents of boys in active play. Sex-of-parent differences were found to be related to child play style. For example, the daughters of supportive mothers engaged in physical contact-seeking behavior, while the daughters of supportive fathers avoided such physical bids. In general, the relationships between mother-child behaviors were similar regardless of the sex of the child being played with, while fathers' behavior related quite differently to girls' and boys' behavior. For example, fathers were supportive of active play in boys but withheld support from girls who engaged in active play. Although these results are no more than tentative, since so few fathers attended the session, they indicate that fathers can play an important part in determining sex differences in children's play styles.