I dunno about "mental disorder", but I'd say we all have an underlying desire to "show them".
just like any other successful businessman or athlete, we tend to think "i'll show them".
we tend to have a chip on our shoulder... something to prove, not only to others, but to ourselves.
when I was a kid, I was skinny. my family (uncles/cousins, ect..) were all BIG farm boys. I remember getting ready for church, or a funeral or something at my grandpas house when I was like 7 or something, and my pants were too big and I needed a belt, and my girl-cousin makes a snide comment like "well, if you weren't so skinny..." .... that comment, and the way she said it really pissed me off, and I remember it to this day. but there were many comments like that that stick with me. even back then I knew I wanted to be a bodybuilder (I'd known since I was about 4-5yrs old, watching bodybuilding on ESPN and seeing Lee haney on tv.. I have memory like Rainman. lol)... so i'd always had in the back of my mind "i'll show them... one day they'll see me and i'll say 'who's skinny now?' "
same as in school... I got bad grades, and some friends parents would tell their kids that I would be a bum and be homeless, and teachers would say/think I was gonna be a dropout and never amount to anything... I wouldn't do homework, but come time for a test or quiz, i'd get 90-95% and they'd think I cheated... one teacher says to me "**** you're 'special', aren't you?" making fun of me in front of the class, thinking I was too dumb to catch on to her sarcasim... I replied, "you're fucking right I'm special", it was right before we had finals, and we graded on a curve. well, I finished at least a half-hour before anybody else. and I got to sit there and look at the teacher staring at me with her smug little look. coming to collect the papers, she says "you really should take this more serious" thinking I just filled in answers.. then she passes out the papers randomly for us to grade, and I get a 98%. everybody was pissed at me for throwing off the curve. i remember raising my hand and telling her, "Mrs. Whatever, your little joke isn't so funny now, huh? told you I'm 'special'."... the look on her face was priceless. i can remember it to this day.