Like other more commonly acknowledged inventions from stone axes to the wheel, number words radically shifted the human story. So the book relates to other work in anthropology that seeks to better elucidate the history of our species. It also relates to work in linguistics on the types of number systems used in the world’s languages. Finally, it is integrated with other recent work in the cognitive sciences that illuminates the distinction between numbers and the coarse innate quantity recognition skills shared by all humans.People sometimes assume that number words just serve as labels to “numbers” in the brain, but this position is actually not well supported empirically. The book suggests that numbers are best considered language-contingent representations of precise quantities, and that most people do not learn to represent quantities precisely until they have acquired numbers. (This latter point is similar to the conclusion espoused by cognitive scientist Rafael Nunez in the most recent issue of Trends in Cognitive Sciences, suggesting that other researchers are thinking along similar lines.)My professional path is ultimately interwoven with my personal one. Some of my childhood was spent in Amazonia with a group of people that do not use numbers. (My father, Daniel Everett, was the first to point out that the language of those people was anumeric.) My personal background certainly helped to motivate my fascination with the development and usage of numbers. All of my research focuses on the interaction of language, cognition, and environment, and the story of numbers is integral to understanding quantitative cognition and the ways in which humans reshaped their environments via numerical technologies.