Some believe this is the result of discrimination: employers, for example, tend to favor attractive employees over ugly employees.

Other researchers believe that beauty is a sign of productivity: beauty can promote self-confidence, which helps in building human capital.

Thinking about this some more... It seems to me that what matters may be the tense of the preferential treatment. Is it happening now, or did it happen in the past?

I think maybe it's not really that beauty builds confidence, but rather that being treated nicely builds confidence, and beauty leads to favorable treatment. If so, then the question is, are the grades higher now because of current preferential treatment or past preferential treatment?

According to Mehic, these findings suggest that discrimination most likely explains the "beauty premium" for female students who no longer had higher grades when classes went remote.

But for male students, who continued to see higher grades with attractiveness even when student-teacher interaction was low, beauty appears to be a performance-enhancing attribute.

So maybe what happens is that males stop receiving preferential treatment for good looks some time before college, but they receive it in childhood for long enough to build up their self-esteem.

Either way, the higher grades would result from preferential treatment - either directly or indirectly. Anyway, there's definitely some interesting nuance there...