While debates over the heritability of IQ and the potential for culture bias in measuring instruments have generated much research and public comment, it is also possible to investigate the significance of interracial differences in mean IQ by ignoring both the foregoing issues and instead examining the social psychology of the test situation itself. Male and female students between 12 and 16 years of age completed the Wechsler Intelligence Scale for Children Performance sub-scales in a variety of settings. The variables of test atmosphere (evaluative or gamelike), tester expectation (high or low), race of tester (black or white), and race of subject were placed in a two by two by two by two factorial design. At a second session some weeks after taking the WISC, subjects completed a group administered questionnaire. The pattern of mean IQ scores as well as mood and personality data indicated that test performance was optimal at moderate levels of motivational arousal. A replication of the experiment for male subjects increased cell sizes to the point that socio-economic status could be treated as an independent variable in the design. When this was done, the results suggested that interracial differences in mean IQ might be erased depending upon the social-psychological characteristics of the test setting and the socio-economic background of the testee. (Author/JM)