I haven't gotten to the end yet, but I think it's strange that it was initially presented as the participants taking the IQ test BEFORE they spoke and ranked each other, when they actually did so afterwards. Stereotype threat says hi.

EDIT: And, at the end... Yeah~

If I may blather a bit myself, though, it's interesting to note that the top four are likely within a margin of error. Good day, bad day, their rank is probably malleable. People like 5, IME, are quite intelligent, and I wonder if the circumstances affected their performance (4's too, possibly even 3's). 6... Well, I think that says a lot about where we are as a society. Though that might be the schadenfreude talking.

On the other hand, you could look at the ultimate ranking as one that leans heavily on each individual's confidence and comfort in the situation. 6's oversharing might have been rooted in nervousness and a sense of inferiority (the kind that might drive someone to, say, a push for high levels of formal accomplishment). Whereas, as someone in the comments pointed out, 3 was calm and relaxed even as they were being told that they were definitely the dumbest person in the room repeatedly. 1 is tall, male, stereotyped as intelligent, academically-accomplished, and acknowledged as such by everyone else; he had the best situational advantage for his headspace, entering the test.