ONE of my colleagues at the University of Virginia, a world authority on how culture influences personality, almost didn’t become a professor. He wanted to teach high school, but went for his Ph.D. because it seemed easier; he thought he would fail the exacting admissions test for teacher candidates. Perhaps I should mention that my colleague is from Japan.

When I tell this story to Americans, they usually nod knowingly, because it confirms their beliefs about the quality of teachers in both countries.

Most Americans think that teaching is a natural talent, not the product of training, and that smart people are the ones with the talent. So some policy makers have concluded that the way to improve schooling is to lure top-scoring graduates into teaching (as Japan does) instead of scraping the bottom of the academic barrel (as America supposedly does). Arne Duncan, the secretary of education, invoked this idea in a speech last year.

But the problem in American education is not dumb teachers. The problem is dumb teacher training.

It’s true that the average SAT score of high school students who plan to become teachers is below the national average. But planning to teach doesn’t guarantee that you’ll succeed in college, pass the certification test and be hired. The median SAT score for those who actually do end up teaching is about the national mean for other college graduates. (There is some variation, depending on teaching specialty.)