A crossnational study compared secondary school boys' and girls' social (individual attitudinal, and family) and linguistics (type/frequency of oral conversations and test related activities) experience, and their relation to differential writing performance. Subjects included more than 1000 secondary students in their final year of compulsory schooling from each of three countries: Chile, Sweden, and the United States. Data from the International Association for the Evaluation of Educational Achievement 1984 study of writing composition were subjected to t-tests, factor analyses, and regression analyses. Results indicated that: (1) in all three countries, girls and boys engaged in distinct activities in their families; (2) in all countries, girls' performance was superior to that of boys; (3) similar factors describing experiences emerged in all three countries, including "family conversation,""student attitudes," and "student literacy activities"; and (4) the model predicted performance in writing much better in Sweden than in the United States or Chile. Findings suggest support for previous qualitative research findings on differences in discourse forms used by males and females, and extended this concept to writing and to differences in different written discourse forms. Findings also highlight the different opportunity structures for males and females as they impact performance and choice in education. (RS)