Thumbs, toes, and tears : and other traits that make us human / Chip Walter

Includes bibliographical references (p. 217-244) and index.

"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 marks a fork in the evolutionary road where we went one way and the rest of the animal kingdom went another." "Science journalist Chip Walter tells the story of how these six unique human traits evolved, and his book provides insights into how we became the remarkable species we are. Drawing on complexity theory, the latest brain scanning techniques, and new insights from fields as diverse as anthropology, neurobiology, and artificial intelligence, Thumbs, Toes, and Tears reveals a creature whose social relationships, sexual behavior, and internal self-image were shaped by its ability to walk upright, make tools, use language, and bond deeply in a dangerous world." "As the story of each trait unfolds, Walter explains why our brains grew so large and complex, why we find one another sexually attractive, how toolmaking 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."--BOOK JACKET.