I think a great deal of societal problems are caused by social 'pressures' and 'norms' (ie. bullying). Remember how terrified everyone was about being perceived as uncool? I remember when I developed an interest in classical music, i pratically had to keep it a secret.

One more point i'd add about the general immaturity and unfairness of school pupils, is that the smart boys are probably unkind towards to the smart girls, out of some sense of competitiveness. I don't have evidence of this but it seemed to be an abundant sentiment when I was at school.