A study was conducted to examine peer effects among 138 undergraduates at Williams College, a highly selective four-year liberal arts school. The study explored whether students would perform better writing about newspaper articles they read and discussed in academically homogeneous or heterogeneous groups of three. In homogeneous groups, all three students were either form the top half or bottom half of their class according to academic ratings assigned at the time of admission. Heterogeneous groups included students from both the top and bottom halves of the class. Results show that students in the top and bottom half performed similarly over all, but that students performed better in homogeneous groups, whether those groups were made up of students from the top or bottom halves of the class. This pattern of results was stronger for men subjects than for women. Results are interpreted in terms of the principles of social comparison theory (L. Festinger, 1954). (Contains 1 table and 14 references.) (Author/SLD)