“…Ecological and developmental epidemiological models of life course development highlight the role of classrooms as unique socialization environments that complement the socialization experiences within the family, peer group, and other main social fields in which the life course evolves (Bronfenbrenner, 1979;Kellam et al, 1991). Results of educational research on classroom predictors of achievement highlight the role of instructional strategies (Bell & McGraw-Burrell, 1988;Slavin, 1987;Umbach, Darch, & Halpin, 1989;Van-Oudenhoven, Wiersema, & Van-Yperen, 1987), classroom management strategies (Berliner & Casanova, 1987;Brown & Saks, 1986;Dreeben & Gamoran, 1986), and ability grouping (Dawson, 1987;Gamoran, 1986;Slavin, 1987Slavin, , 1988. The educational research often stops short of considering how the child's classmates' achievement level or behavior is related to the child's own achievement and to the child's broader behavioral, psychological, and psychiatric status.…”