Race and socioeconomic class differences in children's reading performance are influenced by social and motivational factors. For example, children from poverty backgrounds are more likely to attribute success to conditions outside personal control, and thus do not experience as much pride in achievement as middle class students who have learned to associate success with ability and effort. Parents appear to play a critical role in the development of achievement motivation. Middle class parents generally foster strong achievement motivation by their high expectations of success and their involvement in the achievement-related activities of their children. They influence their children's reading performance more directly by the amount of reading materials they have in the home, encouragement they give, reading they do themselves, and time they spend reading with their children. Students' involvement in reading is also influenced by the kinds of reading materials schools provide and by teacher expectations. Among students from low socioeconomic groups, achievement is influenced negatively by peer pressure. Additional work, particularly on environmental factors, would allow researchers to go beyond the more demographic variables of race or socioeconomic status in exploring performance differences in reading. A comprehensive reference list is appended. (HOD)