Ethnicity, socioeconomic status, and pattern of WISC scores as variables that affect psychologists' estimates of "effective intelligence".

Psychologists estimated "true IQs" or "effective intelligence" from WISC profiles that varied for ethnicity (black, Mexican-American, or white), social class (lower or middle), profile (three scatter patterns), and direction of Verbal-Performance Scale discrepancy. Psychologists gave higher IQ estimates to black and Mexican-American children's profiles than to the same profiles of white children. Social class was not a significant factor. Profiles with much scatter received higher IQs than profiles with limited scatter. The pattern of subtest scores also affected estimates, while the direction of the Verbal-Performance discrepancy was not significant. Finally, the WISC was judged to be more valid for white than for black and Mexican-American children. Explanations of the findings were discussed.