If you thought White Chicks had a high implausibility factor, Little Man is off the proverbial charts. The Wayans brothers -- director Keenen and stars Marlon and Shawn, who split the writing credit among them -- are back with a comedy that proves what mental midgets they truly are. The movie is so suffused with political incorrectness, the viewer has almost no choice but to accept it as a running constant, and thereby almost stop noticing it altogether. Little Man is offensive, and not just to little people. But its greater problem is that it's too obvious by half. The Wayanses have crammed in every possible joke about how a miniature ex-con would take advantage of going undercover as a baby -- let's not stop to ponder that concept too closely -- but haven't come up with anything truly surprising, anything that might provoke laughter among thinking people. Of course he looks forward to breast feeding. Of course he likes blaming his bad behavior on "grown-ups." And of course he fears having his temperature taken rectally. The movie being so predictable tends to overshadow the problem that the scenario is utterly ludicrous. There's no way dozens of normal people would mistake Marlon Wayans for an actual baby, especially given his constant attempts to sabotage himself through unusual feats of strength, agility, and intellect. Just how unusual they are changes from scene to scene. This movie can't decide whether he's supposed to play an infant, given the aforementioned nursing, or a five-year-old, given his unlikely participation in a touch football game. Keenen Ivory Wayans has enlisted a diverse array of sketch comedy veterans to help his brothers, including David Alan Grier, Tracy Morgan, Molly Shannon, and Alex Borstein. But even their involvement leaves Little Man less fun than a bad case of diaper rash.