People should differentiate between introvert, knowledgeable, and intelligent. I most likely qualify for the first two but I wouldn't even begin to guess on how to know whether I'm in the third league.
It's about IQ, not "Intelligent Brains" which is editorial about the validity of IQ sneaking into the headline. It's not hard to know your IQ, there are tests.
Or anybody who went to school and saw how well they learn compared to the average student should have an idea. IQ was originally meant as the predictor of how fast you learn after all.
If the article is true I would assume that the most highly intelligent reader would have a great deal of difficulty commenting on the subject in a reasonable about of time, and would most likely end up short circuiting the effort in favour of doing something else …