Compare the average intelligence test scores of blacks and whites during their senior years in high school and whites tend to outscore blacks by as many as 15 IQ points. But send those students to college and the IQ scores of black students who graduate increase more than four times as much as those of their white college classmates, effectively cutting the black-white IQ gap in half by graduation.
This is one of the key findings of Washington University research that holds important implications for the current debate over federal and state attempts to roll back affirmative action programs.
"Our study shows that differences in IQ test scores among blacks and whites may have little to do with genetics, and much to do with the relative quality of the educational opportunities afforded to blacks and whites," said Mark R. Rank, Ph.D., associate professor at the George Warren Brown School of Social Work.
Other members of the research team are Fredric Q. Raines, Ph.D., associate professor of economics in Arts and Sciences; Mark A. Schnitzler, Ph.D., research instructor in the School of Medicine's Health Administration Program; and Joel Myerson, Ph.D., research professor of psychology in Arts and Sciences.
The journal Psychological Science has accepted for publication an article based on their research, tentatively scheduled to run in March 1998.
The study blasts holes in several controversial theories put forth by "The Bell Curve," a 1994 book by conservative social theorists Charles Murray and the late Richard Herrnstein. The book and its theories on race-based intelligence are credited by some with fueling the attack on affirmative action.
"The message for the affirmative action debate is that black students who finish college appear to make dramatic gains in cognitive abilities," Myerson said. "White students also improve during college, but to a lesser extent.
"The more important point," Myerson added, "is that the level of ability black students exhibit at the end of college would have been greatly underestimated based on how they tested when they took college entrance exams in high school. For at least some black high school students, the SAT and other common college entrance exams may not provide an accurate picture of their potential."
The study began as a response to "The Bell Curve," which contends that blacks are genetically less intelligent than whites and that this intelligence gap cannot be greatly changed by education. Murray and Herrnstein argue that affirmative action programs in higher education offer diminishing returns because blacks lack the cognitive ability to benefit from advanced education, at least to the same degree as whites and Asians.
"The Bell Curve" is based on Murray and Herrnstein's analysis of the National Longitudinal Survey of Youth, a large database that includes intelligence test scores for a broad cross-section of American men and women. The Washington University research team re-examined the same data set used by Murray and Herrnstein and reached dramatically different conclusions.
Rank and his colleagues used many of the same assumptions about intelligence and test scores set forth in "The Bell Curve," but then refined the analysis to account for differences in educational experiences. Their findings suggest "The Bell Curve" substantially overstates the case for race-based intellectual differences because it ignores the important influence of elementary and secondary school educational quality on IQ test scores.
"Look at all high school students, including those who don't go on to college, and you'll find that whites on average increase their IQ scores more than twice as much as blacks during high school," Rank said. "Research shows that many blacks, even those from higher-income families, have less access than whites to quality K-12 education. We suspect that this difference in educational quality contributes to the widening black-white IQ gap at the high school level by holding back some blacks who really have the potential to do much better."
Thus, even though many blacks come to college less prepared than their white counterparts, many manage to overcome this handicap and begin making dramatic improvements in cognitive abilities. The study attributes the rapid improvement of some blacks to the fact that most colleges and universities provide a level playing field, offering educations of relatively equal quality to all students regardless of race.
"We would argue that the constraint of inferior education for blacks at the high school level is largely removed during the college years," Myerson said. "Consequently, black students are able to more fully develop their potential in terms of cognitive ability. The result is that at the end of four years of higher education, black students' intelligence test scores more closely resemble their white counterparts' scores."
Contributing to the admission test problem, Rank said, is the fact that college entrance tests are traditionally taken near the end of high school -- precisely the period when the black-white gap in intelligence test scores is greatest.
Myerson points out that the SAT and other college entrance exams are still fairly good predictors of how well any one student will do in college -- students who score low on the SAT are more likely to have a difficult time in college.
"These tests are still much better than chance at predicting who will succeed in college, but it appears that the same score doesn't necessarily mean the same thing for blacks and whites --a low score may underestimate the potential for some blacks to do well in college," Myerson said.
Rank said: "Contrary to the conclusions reached in 'The Bell Curve,' our analysis of the same data set suggests that education does have a significant impact on cognitive ability. Furthermore, education at the college level exerts a sizable influence on reducing the widely reported differences in white/black intelligence scores. Unfortunately such an effect was virtually ignored in 'The Bell Curve.'"
The findings have implications for debates raging over the use of racial preferences in affirmative action programs, including California's controversial Proposition 209, which makes it illegal to use race as a factor in awarding government contracts, scholarships and other perquisites commonly included in affirmative action programs.
Legal challenges to Prop. 209 have reached the U.S. Supreme Court, and some expect the decision to be one of the most important rulings on racial issues since the civil rights movement.
-- Gerry Everding
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