What is it about Chris Rock that doesn’t play in films? Undoubtedly, he’s one of the best comedians of his generation, but his movie work is forced and weirdly unfunny. He isn’t able to connect with the imagined audience of the cinema lens like other comics—perhaps he’s just a bad actor? The move to documentary “hosting” doesn’t help much, although Jeff Stilson’s Good Hair works as a dissection of African-American hair culture. There are a number of great moments—celebrities like Raven-Symoné, Eve and Al Sharpton testifying to their use of extensions and relaxants; a trip to India to visit the religious sect that sells hair for American weaves; and a bizarre Atlanta hairdressing “competition” that is inexplicable even to the participants. Unfortunately, Rock hogs the spotlight with facile interviews and a half-formed personal angle that doesn’t work.