In sitcoms and campaign ads, in wrestling bouts and movies, the insult blunt, abrasive, in your face has become the heartless signature of American culture. The Super, which stars Joe Pesci as a Manhattan slumlord convicted of building-code violations who is forced to become a live-in superintendent in one of his own tenements, is a case in point. The super disses the tenants; the tenants dis the super; the super disses the sexy prosecutor; she disses him back; and so forth. The film doesn't even take sides. Whoever disses loudest and cruelest wins. Pesci, a genius of runty comic menace in GoodFellas, comes closer here to playing all Three Stooges rolled into one. The Super is witless, repetitive, and borderline racist the sort of inner-city cartoon that depicts minorities as a ''class'' instead of simply as people. D-

