Bell Curve

490 Living Together Affirmative Action in the Workplace 491IQs of 98 or higher; for clerical jobs, the assumption is that they aredrawn from within the range of 86 to 123.'12' The results are shown inthe figure below.A revised view of equal employment opportunity aftercorrecting for ethnic differences in the IQ distributionsBlacklwhite ratio (l=equality)a1964 Civil Griggs Unqorm Professional &Rights Act decision is Guidelines terhniral inhc.vu..... C'. J"""2 - passes handed down are adoptedSource: Bureau of Labor Statistics 1983, 1989; U.S. Department of Lahor1991.m e ratio represents blacks employed in a given c~cupational gnwping expressedas a percentage of eligible blacks, divided hy the whites employed inthe same occupational gouping expressed as a percentage of eliaihle whites.The number of eligibles is determined by the size of the working-age populationin that race who fall within the IQ range for that occupation, as calculatedfrom a table of normal probabilities. The assumptions for computingthe ratio are: (1) the 1Q range for professional and technical jobs is 98 andhigher; (2) the IQ range for clerical johs is 86-123; (3) IQ is normally distributedwith a mean of 85 for blacks and 100 for nonhlacks, with a standarddeviation of 15 for both groups.What "should" the lines look like? If the assumptions in drawing themwere accurate, then both lines should have risen to 1 (to signify thatblacks and whites in the same IQ range are hired at the same rate) afterthe antidiscrimination laws were passed and then hovered near 1thereafter. Anything above 1.0 signifies a higher likelihood for blacks1of being hired, once IQ is held constant; below 1.0, the opposite is true.The proportion of blacks in professional and technical jobs rose above1 in the early 1960s, flattened after the Civil Rights Act of 1964, tookanother steep jump after Griggs, and then settled into a gradual risethrough the late 1980s. For clerical johs, progress after 1964 led to parityin the late 1960s. The relative proportion of hlacks in clerical jobsthen continued to increase at a slower but more nearly linear pace sincethen. In both categories of employment, blacks have been hired athigher rates than whites of equal IQ since the late 1960s, and the upwardtrend lasted at least until the late 1980s.Since these job categories do not have precisely defined IQ ranges,it may be asked what would happen if the assumptions were changed.Some of the alternatives we tried are described in the note to this paragraph.The short answer is that the picture stays essentially the samewithin any reasonable range of assumptions. The overall conclusion isthat hlacks have for some years had more people working in both cler-~cal johs and professional and technical jobs than would ordinarily beexpected, given the 1Q range from which those jobs are usually filled.['''The figure above uses broad guidelines ahout the IQ range from whichcertain jobs are held and applies them to national data ahout occupations.For a narrower focus, the NLSY supplies data about specific individuals,their occupations, and IQs."~' In 1990, using the same definitionof "professional and technical occupations," and after controlling for IQ(set at 113, the mean IQ for whites in such occupations), the proportionof hlacks in the NLSY employed in professional and technical occupationswas 1.5 times the proportion for whites, compared to the ratioof 1.7 shown for 1990 in the graph. For clerical jobs, after controllingfor age and IQ (with IQ set at 103, the mean value for whites holdingclerical jobs), a black in the NLSY was 1.9 times more likely than awhite to be employed in a clerical job, compared to the figure of 1.6 for1990 as shown In the graph.l'5'~he conclusion drawn from national statisticsis thus confirmed by the individual data in the NLSY.Several points may be drawn from this exercise. First, it highlightsthe reality and magnitude of the discrimination suffered by blacks priorto the civil rights movement. As recently as 1959, the employment ofblacks in clerical and professional and technical jobs was only half theproportion that would have been expected from recruitment to thosejobs based on IQ alone. Decennial census data (not to mention living