James Marsh, director of the Oscar-winning 2008 documentary Man on Wire, about World Trade Center tightrope walker Phillipe Petit, says Project Nim, his latest film, was much harder to make. The story of Nim (left), an infant chimp ripped from the arms of his tranquilizer-stunned mother, was “unusually gripping,” says Marsh, whose documentary brought him this year’s best world documentary director award at Sundance and opens in limited release on July 8. Selected in 1973 for the titular Columbia University project intended to teach primates sign language, Nim passed from the Upper West Side brownstone of a “rich hippie” mother of three, who raised him as she would a human baby, to a New York University lab, where he was used to test hepatitis drugs, to, finally, a Texas ranch of soul-crushing isolation. To tease out the essence of this maligned primate a decade after his death, Marsh spent two years melding re-enactments, archival footage, and interviews with the human players, whom he forced to speak in the present tense. “What I didn’t do was privilege them with the benefit of hindsight,” says Marsh, who tackles, among other things, our confounding ability to rationalize the morality of animal domestication. “Chimps are…very forgiving,” NYU veterinarian James Mahoney concludes. Or so he hopes.