What is the historical basis for the US obsession with intelligence testing and the assumption that IQ is a valid measure of intelligence?

There's absolutely nothing wrong with researching intelligence, but it seems like the US puts a disproportionate emphasis on intelligence testing, sees it as a key factor in results in many areas of society, assumes that IQ is a good measure of intelligence, and assumes that intelligence is a strong factor in success. For example, there are programs like the baby Einstein DVDs and the Mozart effect that claim to be able to make babies more intelligent, and the only reason that there is such a strong anti-vax sentiment is because of a now-discredited paper claiming a link between vaccines and autism.<br><br>Even if it were true that IQ were a good measure of intelligence, people with different races, genders, ages, and classes have vastly different IQs. And yet, there is just as much variation between people within each group as between different groups. As Chomsky said, "If you take a third-grader in the United States and compare them with the best university in Birmingham, England, the third-grader will win, hands down. Americans are the best-educated, the best-fed, they see more doctors, more dentists, they have more cars per head of population than anyone, and yet they are less likely to read a book than anyone. They work longer hours than anyone else, practically. They accept the authority of those above them, an absolutely egalitarian society, they love their masters. You don't find that anywhere else today, and they're worth a hell of a lot, so you want to keep them at your knees, and you want to explain why it's your fault that you're so dumb." As you can see from the above quote, Chomsky traces this to capitalism, specifically the American model of capitalism, which is designed to keep the largest amount of wealth possible in the hands of a small elite class, and thus has to find ways to prevent the 99% from gaining power that they can use to revolt.<br><br>It's not like the idea of measuring intelligence is inherently bad, but it is clear that capitalism's obsession with measuring IQ is a way to control society, and thus has a lot of problems and biases.