Nim Chimpsky is Elizabeth Hess's recounting of the ill-fated attempt to teach a chimp American Sign Language—and the issues it raises about our treatment of animals.

This experiment took place in the 1970s. Why has it taken so long for Nim's story to be told?

This story was really swept under the rug. Everybody wants to forget about Project Nim. Many of the people who are writing both the history of animal protection and the history of legal issues around animal personhood and animals as property always skip over Nim because the main researchers in the project insisted that the whole thing was a failure. In fact, a lot of researchers were skeptical when I asked them to discuss Nim. One said, “You're kidding. You're writing a book about Nim?” But many of the people involved with Project Nim, especially those who actually lived with Nim, are still extremely upset that the project ended so abruptly. Many wept through their interviews. They were happy that Nim's story was finally going to be told.

Was your interest in Nim connected to your experiences writing your previous book, Lost and Found: Dogs, Cats and Everyday Heroes at a County Animal Shelter?

I was looking for a story and an animal that would give me an opportunity to write about all different aspects of the landscape of animal science and animal politics, and Nim was ideal for that. But while I had to immerse myself in the complicated issues of primatology and linguistics, this isn't really a science book. Looking at all the power arrangements around Nim—who got to decide what happened to him—was fascinating in itself, and Nim is as interesting as the people who surrounded him.

Your book ends with a description of Nim in his cage seeming to ask the question, “Why am I here?” Why did so many of the people you interviewed seem never to have asked that question for Nim?

When I began writing, I was astounded that there was no exit plan for the chimp, from the beginning. But the fact is that animals born into captivity never get free. It's a very different way of thinking about animals than we are used to. Even graduate students don't understand what the life of a captive animal is like. It's a question that's trained out of them. There are no easy answers, but I want this book to ask people to examine that issue.