It's not BAD, per se, it's just a bit "here be bullshits". Surely no school could have an equal amount of smart, thick, slightly thick etc. kids? I don't buy it

Despite being a comprehensive, my junior school operated a startlingly overt segregation regime, in which every pupil was assigned to one of four groups according to their academic ability.

Kids in blue group were clever, those in green group were average, red group was for thickies and yellow group - well, these were the kids who couldn't spell their own name.

Movement between groups was rare, though this didn't stop the (ironically named) David Smart moving from blue to green to red in the space of a term, presumably as the teachers became incrementally aware of his stupidity.

(Actually, come to think of it, David wasn't all that thick - but he *did* stink of cat piss)