This trenchant documentary by James Marsh (Man on Wire) exposes the foolishness of our tendency to anthropomorphize animals. In 1973 a baby chimpanzee called Nim was torn from its mother at a primate research lab in Oklahoma to become the subject—and media star—of a Columbia University study in language development. A surrogate mother, Stephanie LaFarge (the former lover of project head Herbert Terrace), took the infant chimp into her Manhattan apartment and reared it as part of her own large family, teaching it to communicate through sign language for the deaf. But LaFarge’s resistance to strict scientific protocol resulted in Nim being relocated to a sprawling estate in Riverdale, and its signing ability increased rapidly under the tutelage of undergraduate Laura-Ann Petitto (who would also become romantically involved with Terrace). Sexual politics, family dynamics, the debate over heredity versus environment, and the dubious ethics of scientific research on animals are rigorously explored in this ambitious, bittersweet work.