The Math Gene: How Mathematical Thinking Evolved and Why Numbers Are Like Gossip

Recently, luminaries like Steven Pinker have shown lay audiences neat theories about how language works and how our ""language instinct"" evolved. In the same years, writers like David Berlinski have made higher math entertaining and accessible. Here, prolific math writer and NPR commentator Devlin (The Language of Mathematics) has joined these two strands of popular science writing. Using up-to-date cognitive psychology, along with the history of math, Devlin aims to unfold our ""innate sense of number"" and to show what it has to do with language. He also hopes, more ambitiously, to win readers over to his own hypothesis about how our language and math ""instincts"" arose. Experiments show that chimps, like us, ""use symbols to denote numbers,"" though human toddlers are far better at it. Combining a number sense with symbolic abilities, we use abstractions to manipulate quantities, leading to arithmetic and potentially to calculus and number theory. After several stellar chapters devoted largely to psychology experiments, Devlin switches gears to higher math, giving examples of how abstract models describe concrete things--from rotating clock faces to rattlesnake skins. The book takes another sharp turn, into the stimulating but quite crowded field of hypotheses about how our brains came to be. While responsibly laying out several hypotheses, Devlin favors the idea that enhanced symbolic abilities let early hominids think ""off-line,"" asking and answering ""what if"" questions about tools, predators, habitats or prey. Some may wish Devlin had written two books--one about math and language, the other about language and evolution; the former would likely ace the latter. Most readers, though, will appreciate the broad, accessible syntheses he does provide. 35 illus. (Sept.)