Almost Chimpanzee: Searching for What Makes Us Human in Rainforests, Labs, Sanctuaries, and Zoos

How are we different from chimps? That's the question that Cohen (Shots in the Dark) sets out to answer in his absorbing account of current chimpanzee research. Too often, Cohen argues, scientists have focused on the similarities between the two species, when in fact it is an understanding of their differences that can reveal "what, exactly, it means to be human." Cohen's survey spans investigations into the chimp genome, brain, and physiognomy, with a fascinating chapter on chimp sex (one captive female chimp was observed "flipping through Playgirl, sometimes using a vacuum cleaner hose for stimulation") and a colorful portrait of Richard Lynch Garner, a 19th-century adventurer who lived in a cage in the jungle for 112 days, studying and recording chimp and gorilla language. The technical jargon of some sections can be difficult, but the book is otherwise readable and replete with surprising theories for the origins of human traits from "concealed ovulation" to endurance running. One scientist, for instance, believes that humanness derives from the simple fact that our babies, unlike their ape counterparts, can lie flat on their backs, which allows them to gaze into their mothers' eyes. (Sept.)