I'm lost!
Possibly the first thing to note here is that The Answerbank is a UK-based site, where the SAT test for college admission isn't used. (I had to use Google to find out what it meant). So this might not be the best place to seek an answer to your question.
However, even so, I can see nothing in that article that supports your statement that people with the lowest IQ had the highest SAT scores. Indeed, the scatter diagrams labelled a and c seem to show exactly the opposite!