Adam Simon's documentary The American Nightmare (Independent Film Channel, October 19, 28, and 31) does an admirable job of reclaiming 1970s American horror movies from cultural purgatory. Using interviews with directors, film scholars, and other interested parties, Simon exposes the grim social undercurrents that incubated such gag-reflex classics as The Texas Chainsaw Massacre and Shivers. Raised on a television diet of monster movies, nuclear paranoia, and Vietnam War atrocities, this group of filmmakers skipped the camp-out at Woodstock and bunked instead in the Last House on the Left. Simon gets relaxed, thoughtful commentary from out-of-commission greats like George Romero (Night of the Living Dead) and Chainsaw's Tobe Hooper, while Wes Craven waxes philosophic without having much to say. David Cronenberg, who broke out of the horror ghetto long ago, is the most insightful of the bunch. Genre squatter John Carpenter makes the grandiose claim that his Halloweenthe original horny-teens-in-peril moviefinished off the sexual revolution, but ignores the fact that it drained the innovation from American horror films seemingly for good. Little wonder that Simon ends his examination before having to address the deluge of Halloween sequels and imitators that leaves a sticky trail all the way to the likes of Scary Movie.