Lucy is a quick, entertaining read. Temerlin, while not a "professional" writer by any means, writes a narrative of raising Lucy that is both fascinating and charming. Scientific? Not really. Unlike most of his cross-fostering counterparts, Temerlin was not an experimental psychologist, but a psychotherapist. Thus, the audience is treated to Freudian interpretations of both the author's and Lucy's behaviors. In many ways Temerlin's book tells us much more about Temerlin himself than Lucy. Still, a great read.
Nim Chimpsky does not read as quickly or fluidly as Lucy, despite the fact that Hess is clearly a superior writer. The third-person after-the-fact account of Nim Chimpsky gives the reader a better idea of everything going on around Nim throughout his life. In many ways, it reads like several miniature biographies of those involved in raising Nim and in Project Nim in general.
Overall, three conclusions can be made from reading these books:
1. Cross-fostered chimpanzee studies really do show how closely-related humans and chimpanzees are.
2. Cross-fostered chimpanzee studies also show how incredibly different and wholly "not human" chimpanzees are. They are wild animals. In both Lucy and Nim's stories, chimpanzee adulthood ultimately led to the chimp being sent to a sanctuary or other facility equipped to handle adult chimps.
3. Although useful (at the time they were done) for increasing our understanding of chimpanzee intelligence and behavior, chimpanzees should not be raised in human homes or in captivity at all. They are not a domesticated animal, and even the best in-captivity environment is worse for chimpanzees than living in the wild.