IQ Blackout: Why Did Studying Intelligence Become Taboo?

Scholars used to avidly study human intelligence. They measured cranial capacity. They administered IQ tests. They sought to define what intelligence was and who had more or less of it and why.

These days, not so much. Somewhere along the way, the very idea of intelligence became politicized. Its legitimacy as a field of study, as a measurable quality -- on par with height, eyesight and hand-and-eye coordination -- and as a concept came under fire. Talk of "brainpower" and "smarts" ebbed as scholars proposed "multiple intelligences" -- such as musical, spatial, interpersonal and intrapersonal -- rather than whatever had hitherto been called IQ. An IQ blackout has descended. When researchers talk about IQ at all, the big question is whether it's inherited, and if so, how much. IQ now faces fierce competition from SQ and EQ, social and emotional intelligence, two burgeoning theories.

Why are our minds and their capabilities among the most taboo topics in 21st-century academia?

"I believe there are a number of factors involved," says Dennis Garlick, a postdoctoral researcher in psychology at UCLA and the author of Intelligence and the Brain: Solving the Mystery of Why People Differ in IQ and How a Child Can Be a Genius (Aesop, 2010). "Certainly a major factor is the race issue. Arguing that the races differ in IQ has tainted the whole field, and many researchers and commentators would prefer to just avoid the area for fear of being labeled racists."

Much of that taint and fear dates back to the work of UC Berkeley psychologist Arthur Jensen, whose writings in the 1960s linking differences in cognitive ability with differences in race sparked protests on the Berkeley campus and outrage in the scientific community that echoes to this day.

"The most important fact about intelligence is that we can measure it," Jensen wrote in his most famous work, "How Much Can We Boost IQ and Scholastic Achievement?" published in the Harvard Educational Review in 1969.

"IQ is known to predict scholastic performance better than any other single measurable attribute of the child," Jensen wrote.

Asserting that intelligence is "heritable" -- that it's mainly in our genes -- he then warned against making racial generalizations: against, in a sense, being racist.

"Whenever we select a person for some special educational purpose ... we are selecting an individual, and we are selecting him and dealing with him for reasons of his individuality. ... Since, as far as we know, the full range of human talents is represented in all the major races of man and in all socioeconomic levels, it is unjust to allow the mere fact of an individual's racial or social background to affect the treatment accorded to him."

Jensen then went on to advocate diversity, although not quite in the same way we do today.

"Schools and society must provide a range and diversity of educational methods, programs, and goals," Jensen demanded: In other words, diversify the curricula, not necessarily the faculty or student body.

"Jensen is still greatly respected by many traditional intelligence researchers," Garlick says. "By 'traditional intelligence researchers,' I mean researchers who still value IQ and continue to do studies that evaluate the effectiveness of IQ in predicting outcomes, or studies that examine possible mechanisms that may cause differences in IQ. However, due to the unpopularity of Jensen’s findings, this group of researchers is now very small.

"The major move in response to Jensen’s findings hasn’t been rigorous and compelling research to try and disprove his hypotheses and findings. Rather, it has led to an exodus of researchers away from the area, and a drying up of grant funding and research positions for researchers interested in IQ."