This study investigated the relationship between (1) achievement marks assigned by teachers to elementary grade, lower socio-economic status boys and girls, and (2) pupils' racial background, sex, intelligence quotient, and tested achievement. A pupil and a teacher sample were chosen from five Minneapolis inner-city schools. The pupil sample contained 62 American Indian, 46 Negro, and 143 white children. The teacher sample contained nine male and nine female white teachers. The children were classified by sex, race, grade IQ, tested achievement, and teacher assessment of achievement. A comprehensive statistical analysis was performed, including a three-way analysis of variance, and an analysis of covariance. Findings include the following. Girls obtain higher achievement scores than boys. When achievement scores are adjusted for IQ, the same sex differences occur. Differences in IQ scores do not exist between sexes. Differences in IQ scores exist between Indian, Negro, and white children, with the latter obtaining higher scores. Differences do not exist between boys and girls in achievement-group scores. These findings have important implications for curriculum design and the deficit theory. (JM)