I think this argument is overly general, as it can be applied to any kind of excellence: jock kids are exceptionally athletic, and they care much more about being athletic than being popular, hence, according to Graham's argument, they should be failing at being popular, while in the American school system they succed.

It's true that athletics are very demanding (I remember vividly the absurd amounts of time my high school's football team demanded of its members), but in practice, athletics does seem to somehow escape the double-bind of 'you cannot serve two masters'.

Is it general physical fitness and attractiveness? Yes, I bet that's part of it (although it makes one wonder if there's a causation/correlation confusion). Is it immediate advantages from intimidation due to physical size? I remember the football players at my highschool benefited a bit from this, from simply being huge, but it doesn't seem adequate. Is it the tribal nature of sports, in warring against the enemy school, where athletics short-circuits the need to earn popularity the hard way by players wrapping themselves in the proverbial flag? It'd explain why the competitive sports like football seem to elicit the most admiration of its athletes (and huge donations from alumni), and various track and field events ignored by most students. I like this as the biggest factor.

If I were going the correlation route, I'd probably appeal to the same excuses universities make in choosing on non-academic merits: the kids who do aggressive sports are generally more likely to succeed spectacularly in business or life and earn lots of money which they can donate back. (Consider the Terman study which found massive lifetime income returns to being extraverted.) So when the girls flock helplessly around the football team, making them 'popular' even though they are specializing in football and not 'being popular', they are executing an effective choice of future allies and boyfriends. (How many football stars marry their highschool sweetheart and go on to success...?)

I wonder whether this "popular jock, unpopular nerd" phenomenon is specific to the American, and perhaps to a lesser extent Western, culture. AFAIK, in East Asian cultures such as Japan and South Korea, school popularity is positively correlated with scholastic performance, probably with good reason, since in these countries scholastic performance is highly correlated with future income and social status.

I can only speak from my extensive anime-watching experience (he said, self-mockingly), but I get the impression that athletics is a great way to popularity and girls in Japan as well. Yes, the 'ideal student' archetype will be great at sports and academics, but that's true in the US as well, and it seems that if you can't have both, better to go with sports.