In The Human Edge, cognitive scientist, poet, and translator Keith Holyoak takes a fresh look at what makes human intelligence special. His focus is analogy--the ability to see relational similarities between things that on the surface seem unalike. The book brings together a half century of research in cognitive, comparative, and developmental psychology, coupled with work in philosophy, law, education, linguistics, neuroscience, and artificial intelligence. Rather than simply examining analogy as an isolated human ability, Holyoak places it in the broader context of a trinity of special human capacities--analogy, language, and understanding the minds of other people. Each of these capacities relies on distinct neural circuitry in the human brain.

Holyoak analyzes the similarities--and critical differences--between cognition in humans and in other intelligent animals, ranging from crows to chimpanzees. He also traces how relational thinking develops in children, emphasizing the distinctive advances that begin at about age three. Along the way, Holyoak paints a broad picture of how people use analogy in everyday life--to make jokes, to argue, to teach, to make moral judgments. He considers when an analogy counts as rational evidence--for or against a scientific hypothesis, or the judgment in a legal case. He also evaluates the most recent advances in artificial intelligence that have started to achieve complex tasks previously limited to humans, while highlighting the distinctive aspects of human creativity.

In a time of rapid technological change, with ominous portents for society, this book provides a timely reexamination of what really counts as the human edge.