Remember the Yanomamö, those Amazonian people you read about in Anthropology 101? They wore loincloths, snorted hallucinogenic drugs, hunted monkeys, and became the most famous preliterate tribe in the world? This documentary studies the sad underbelly of Yanomamö fame and the anthropologists who went all Catholic Church on them—taking kids for wives (just because the locals do it doesn’t mean you get to), turning packs of children into prostitutes, and introducing measles to “virgin-soil” populations (on behalf of a U.S. government study on biological warfare) who died in droves. Secrets is a fascinating swan-dive into a real-life heart of darkness. By Brendan Kiley