They have group think hubris, still

Common sense is intelligence. Intelligence is the application of knowledge, after all. What most people confuse with intelligence is really only knowledge. You can get by in university without ever having an original thought, not to say there aren't intelligent people in university. But the pre-requisite for intelligence is originality in my book. It's why you can have a genius IQ and appear as anything but.

For any metric you can quantitatively test, you can create a bellcurve. For instance, I can create a test where I ask people to look at pictures of circle and ovals and see how quickly they can count the circles. Whether that metric has any significance, however, is up to your own bias.