A fascinating new theory traces the origin of language back to the development of the human pair bond and shows how language propelled human brain evolution. The greatest mystery of evolution is the development of human language, a form of communication different from anything else in nature. This exciting book advances Terrence Deacon's entirely new explanation of the most remarkable accident in the history of life. Departing from conventional theories of language as arising, somehow, once the human brain became large and complex enough, Deacon shows how the human brain and language developed in concert, explains the process by which this occurred, and draws out the compelling implications of this new view of human origins. The most intriguing of these implications is a new explanation of language's adaptive purpose. Delivering a knockout blow to the traditional idea that language evolved to meet the needs of hunting males, Deacon argues that the seeds of language grew and developed in pair bonding between proto- and early-human males and femalesin other words, because of the special needs of the human family. Drawing on the author's own breakthroughs in human and comparative neuroscience (including why other intelligent animals are incapable of language) and in evolutionary anthropology, and on the latest findings of research on artificial life and artificial intelligence, this is science writing at its best, a book that will profoundly alter our understanding of what it means to be human.