Yeah. As much as the typical 'cliche' seems to be a divide between the popular moron jock and the unpopular nerd, the truth is simply that's there's no correlation between popularity and intelligence one way or the other.
Some people may be unpopular but smart or popular but dumb, but there's just as many unpopular idiots and popular geniuses.
Yep. Plenty of folks much more popular than me in school were also fairly smart. As has been mentioned, a lot of it had more to do with social skills but also with "luck of the draw" type things like being more attractive, being more athletic (which often went along with being more attractive), and having parents with more money to buy them fashionable clothes, and better toys (actual toys at a younger age, stuff like cars when older).
Who knows? Maybe a lot of their confidence and social skills were a result of those physical and material advantages. I can imagine that I might have been a more confident and outgoing teen/adult if I'd spent my life as a good-looking kid who wore the latest kid-fashion, was good at sports, and had things other kids wanted to play with. Instead I was scrawny with thick glasses, hand-me-down clothes, a lack of strength and coordination, and very few cool "things". So it didn't matter how smart I was when kids brushed me off as a "nerd" and talked shit instead of wanting to hang out. Either way I was gonna end up socially uncomfortable.
But that's just me and not the same for anyone else per se. And it leads to the fact that it's made me an adult who understands how big an impact the "hand you're dealt" has on the outcome of your life. I think it's helped me to develop a good sense of empathy and I've always tried to put myself in other people's shoes when I have a disagreement or conflict. So much of who we are is shaped by things out of our control and there's a certain strength and clarity that comes from recognizing this and accepting that you can't change some things but you can work toward others.
Some people may be unpopular but smart or popular but dumb, but there's just as many unpopular idiots and popular geniuses.