Differences in social-psychological environments between parochial and public schools, and between mathematics and English courses, were investigated involving 317 grade 10 boys and girls. Multivariate and univariate analysis of variance produced significant main effects and School x Subject interaction. Differential validities of environment variables in predicting achievement using multiple regression suggested that perception of learning environment in a subject substantially predicts achievement in that subject. Incremental validity of learning environment in the context of IQ with achievement is also substantial. Implications for instructional effectiveness and school organization are discussed. (Author/GK)