I read this book back in 2003, when going through a spate of reads about ape language experiments- efforts made by the scientific community to teach gorillas and chimpanzees sign language or vocal speech (mostly a failure, but quite interesting nonetheless!) This particular book was written well before most of those experiments, but is along a very similar vein. The author was curious about how intelligent chimpanzees actually are, and if one could learn to speak if it were raised like a human child. So assayed to raise a chimp within her family, named Viki. The Hayes soon discovered that although the chimp was quite intelligent, Viki could also be very stubborn and willful, so it was not always easy to discern whether she understood a request or was just refusing to follow it. Viki proved incapable of learning to speak, although with some physical manipulation ("speech therapy") she was able, with a lot of coaxing, to pronounce four simple words. Not always able to use them in proper context, though. She also learned quite a few routines and human behaviors, although again, not consistently, and was never learned to use the toilet, despite all efforts to train her. I am sure there were a lot of anecdotes from Viki's story that intrigued me when I first read this book, but cannot quite recall them now. If I come across it again will certainly make an effort to read it one more time.