[Demloth of Dol Amroth]

boromir wasn't by nature, evil-he was royalty, and being royalty tends to give one "i want it and i want it NOW" type attitude. the fact that Denethor favored him most likely amplified this. not saying he was some sort of spoiled brat; he had good intentions and a resilient spirit, which made him mature, just that underlying attitude was more vulnerable to the corruption/seduction powers of the One Ring. the cold hard proof he could be snooty at times was his vain reply to aragorn-"Gondor has no king. Gondor needs no king." this also shows he may have had disdain for folk of lesser import-he was the son of the steward of gondor, aragorn was some wandering vagabond with a sword, to him. in the end, yes, he was ultimately redeemed-lays down his argument and contempt for aragorn, and disavows his desire for the ring. but enough of my ramblings.