You didn't have to be a genius, then or now, to recognize what hooey that assertion is. The only thing IQ tests measure is the ability to score well on IQ tests. If a test yields consistently different results across different populations, the object of study should be the test, not the population.
I had thought that respectable scientists outside such intellectual backwaters as the Heritage Foundation had noticed this. The much mourned Stephen Jay Gould eloquently demolished such drivel in The Mismeasure of Man.
But apparently educational psychologists remain mesmerized by and convinced that their tests prove something. At the very end of a long obituary, the Times saw fit to include incisive criticism of the malign malarky Jensen came to stand for:
I'm sure Professor Jensen was a perfectly nice human being to people in his world. But his theories have supported vicious undermining of the educational struggles of disadvantaged people.