"A fluid introduction to the development of the human species."--"Booklist "Among the countless traits and behaviors that separate us from the rest of the animal kingdom, six stand out--our big toe, opposable thumb, oddly shaped pharynx, and our abilities to laugh, kiss, and cry. Though seemingly unconnected, they are actually closely linked, each marking a fork in the evolutionary road where we went one way and the rest of the animal kingdom went another. Drawing on complexity theory, the latest brain scanning techniques, and new insights from fields as diverse as anthropology and artificial intelligence, science writer Chip Walter explains why our brains grew so large and complex, why we find one another sexually attractive, how tool making laid the mental groundwork for language, why we care about what others think, and how we became the creature that laughs and cries and falls in love. Original, informative, and thought-provoking, "Thumbs, Toes, and Tears "will increase your sense of wonder and appreciation for how unique "Homo sapiens "truly is.