Abstract: | Discriminative stimulus control over masculine and feminine sex-typed play behaviors was investigated in five boys, aged 5–8 yr, with “childhood crossgender identification.” Reliable observational measures of play were obtained with two sets of toys: (a) “dress-up toys” (girls' apparel vs boys' apparel), and (b) “affect toys” (maternal-nurturance play vs masculine-aggression play). With an ABA reversal intrasubject design, certain stimulus conditions (e.g., presence of father, mother, male, or female stranger) were found to be discriminative for reliable changes in sex-typed play. Sex-typed play was found to vary as a function of the social stimulus situation and as a function of the type of play response required. All children played predominantly feminine while alone in the playroom. While no single environmental stimulus was consistently discriminative for masculine play across children, at least one stimulus condition was found for each subject under which he played predominantly masculine. |