Every three years, half a million 15-year-olds in 69 countries take a two-hour test designed to gauge their ability to think. Unlike other exams, the PISA, as it is known, does not assess what teenagers have memorized. Instead, it asks them to solve problems they haven’t seen before, to identify patterns that are not obvious and to make compelling written arguments. It tests the skills, in other words, that machines have not yet mastered.

[Related: Latest PISA test scores cast doubt on U.S. education efforts.]

The latest results, released Tuesday morning, reveal the United States to be treading water in the middle of the pool. In math, American teenagers performed slightly worse than they usually do on the PISA — below average for the developed world, which means they scored worse than nearly three dozen countries. They did about the same as always in science and reading, which is to say average for the developed world.

But that scoreboard is the least interesting part of the findings. More intriguing is what the PISA has revealed about which conditions seem to make smart countries smart. In that realm, the news was not all bad for American teenagers.

Like all tests, the PISA is imperfect, but it is unusually relevant to real life and provides increasingly nuanced insights into education for researchers like Andreas Schleicher, who oversees the test at the Organization for Economic Cooperation and Development. After each test, he and his team analyze the results, stripped of country names. They don’t want to be biased by their pre-existing notions of what teenagers in Japan or Mexico can or cannot do.