http://www.salon.com/books/int/2008/03/31/Nim_Chimpsky/
After funding ran out and Terrace declared the project a failure, Nim was taken from his loving home in New York, and bounced around various grim research facilities before he wound up at Cleveland Amory's sanctuary, in Texas. Tell me about what it was like for Nim to be put back in a cage with other chimps after he'd only ever known humans.
It was terrifying. One graduate student described the response that all the [research] chimps had [upon being reintroduced to other chimps] as a nervous breakdown. Nim's brother [and the subject of another study] Ally was so terrified and upset that he suffered a kind of paralysis for a while. They often pull out all their hair; they refuse to eat; some get beaten up by other chimps because they don't know how to respond to them.
The former graduate students in New York believe that Nim had no idea he was a chimpanzee. One of them suggested to me that Nim might have thought he was going to grow up, lose all his facial and body hair and eventually look like the people who were around him. That would be a reasonable supposition. Throughout his life, Nim preferred to be with humans.
Toward the end of his life, he was paired with an ex-circus chimp named Sally Jones. That, I think, was the first deep relationship he had with his own species. They were inseparable. Sally was a lot older, a lot milder. Nim had a reputation for breaking out of his cage in Texas. When Sally came, he would break out of his cage, but then he'd remember her, and he'd go back and get her. He'd lead her out of the cage and they'd go on a little romp together. Cleveland Amory was always afraid that Nim was going to run off into the woods. But he had no desire to run away. Nim would go to the nearest house and bring Sally with him, and they would raid the refrigerator, go through the closets and try on any shoes that were lying around, and sometimes they'd get into bed and turn on the TV.