How did the A class become ordinary while B&C had a mixture of top and average? Was it that the ordinarily smart students were motivated by the sorting exams than the top smartest students?
I think part of it was that the sort happened when we were ~10yo? People from A-class were the sort of straigh-A student that then coasted on the fact learning came to them ~naturally, so maybe that is why the perceived performance declined.
Even more anecdotal thing, in my class there were more people doing extra-curicural contests, like Math-Olympiad and the like. We were even encouraged by teahers, along the lines of "No, try it even if you don't have top grades, that is the sort of thing where you need to understand what you are doing, not just ave all the right answers on the test." :D
Last hypothesis of mine is, that because we had a mix of sudents, the smarter(?) of us spend some time explaining to others (mix of goodnes of heart, being bullied and even having like a pay-for-homework manufacture?) ... and as they say, you learn best, when you explain?
But I could be completely wrong, rose-tinted glasses and long forgotten traumas and all that :D
