Not until he was nearly 25 did it occur to Robert Williams that he might not be, as he recalls it, "altogether dumb and stupid." Like most young blacks in Arkansas in the 1950s, he was discouraged from going to college, partly because he had always scored in the 80s on IQ tests (average is 100).

But after high school Williams tired quickly of construction work and parking cars and put himself through a small black college in Little Rock. Then he took a chance and applied to graduate school at Wayne State in Detroit, even though he had not tested well again. Once accepted, he found, to his surprise, "I was thinking as clearly and doing as well as the white students."

Today Williams, 47, is a professor of psychology at Washington University in St. Louis, where his main concern has been devising intelligence tests that can accurately measure black youngsters' potential.

IQ tests—in use for nearly 75 years—have been widely excoriated recently. California sociologist Arthur Jensen argues that test data indicate blacks are inherently less intelligent. His thesis has prompted charges that the tests are biased, designed to fit the cultural experiences of middle-class white children. The NAACP, for example, is backing a suit in San Francisco to stop black pupils from being placed in "mentally retarded" classes on the basis of standard test scores. (Williams has been called as an expert witness in the case.) The argument isn't new. A primitive IQ test given in New England in the 1850s prompted psychologists to theorize that Irish-Americans were prone to idiocy.

Williams came from a poor Arkansas family—his parents had no formal education whatsoever. Now he lives comfortably in a spacious home in a prosperous section of an integrated St. Louis suburb, but he still refuses to let any of his eight children take standardized IQ tests. "My kids need education," he says, "not testing. If they are tested, the tests should help us understand what their educational needs are." That, theoretically, is what IQ tests do, but the school superintendent has acceded to Williams' wishes for his children.

At Washington University Williams is sometimes called "savior" by grateful black students, but many of his faculty colleagues take a harsher view of his "Black Intelligence Test of Cultural Homogeneity." (Williams has nicknamed it "Black Intelligence Test Counterbalanced for Honkies, or BITCH.") "They've called me a separatist," he acknowledges, "saying I was really talking about lowering standards for blacks." He also received an anonymous letter saying the FBI had proof he was a Communist.

The critics did not change his mind but did, he says, contribute to a case of high blood pressure. "When you're fighting the system all the time, you stay angry all the time," Williams says. "I was like a car with both the accelerator and brake down."

His test has been used experimentally in other parts of the country, and he was asked by the St. Louis police department to devise an unbiased exam for job applicants. The Police Board backed off upon learning that it would take two years to design and cost $200,000.

Williams' aim, he says, is to end what amounts to "death sentences"—the "low IQ" tag that black children acquire early and are stuck with the rest of their lives. "When I did well in school, administrators would say my below-normal test results were a fluke," he recalls. "I'm saying that the standard IQ test is not an adequate measure of black students' abilities, of their capacity to profit from further experience or of what they're going to do in the future."