Nim Chimpsky was the name given to a chimpanzee, the subject of a communication study conducted by a Columbia University professor and his students in the 1970s where Nim was raised like a human child. Marsh (Man on Wire) and his team revisit the study through old footage---and some clumsy reenactment---tracing what happened to Nim afterwards. But his documentary is much more about humans than the chimp, and it’s an indictment of how unthinkingly cruel we can be as a species. At best, with one or two exceptions, the people who had contact with Nim come off as painfully selfish and naive, though some now have regrets about how they behaved---just count how many times “power” is mentioned in light of social interaction. This is affecting stuff for anyone with a shred of empathy.