A study examined the match between the vocabularies of children of different ethnic and socioeconomic status groups and the school vocabulary revealed by readability formulas and word lists. The Spache 1040 and the Dale 769 readability formula word lists were used as indicators of school vocabulary in the early primary grades, and a corpus of talk involving thirty-nine 4.25- to 5-year-old children grouped according to race and social class served as the indicator of the children's vocabularies. A comparison of the two vocabularies showed two significant biases in the readability formula word lists: (1) against working-class as opposed to middle-class children (which was evident on both word lists), and (2) against black was opposed to white children (which was more pronounced on the Spache than on the Dale list). (Author/FL)