Riddle me this: Why do people love puzzles so? Semiotics professor contends that humans need 'relief' from the angst of big questions: Do you stop to watch the neighborhood chess game? Can memories of ETS problems from exam days ("Two cars are hurtling toward each other at 120 mph ...") trigger instant seratonin spurts? Is a day without your crossword a Code Blue emergency?

If you're a "yes" man or woman in these situations, Marcel Danesi sympathizes. In fact, this professor of semiotics and anthropology at the University of Toronto considers you representative of the human species. We're all born, he believes, with an "instinct for puzzles" and a sharp joy in them. His preface boosterishly drives home that belief. "Why does everyone love a good puzzle?" he begins. "Why do puzzle magazines, brain-challenging puzzle sections in newspapers, and game tournaments appeal to hordes of ordinary people from every walk of life?" Danesi does not assume that the "puzzle instinct" is another characteristic brought to us by natural selection. Instead, Danesi launches into an intriguing survey of the history and rationale of puzzles, lacing in his views about our passion for them as he goes. Guiding through history So we learn about the Egyptian Rhind Papyrus of 1650 B.C. ("Essentially a collection of mathematical brainteasers"), hear how Charlemagne employed a court puzzlemeister, and realize that puzzles constituted a multicultural mania from the beginning. A good 13 centuries before Saddam Hussein, inventor Mohammed ibn Musa ibn Shakir of Baghdad invited the international community to inspect his "Book of Ingenious Devices." Danesi steadily brings us through the history, citing the magic squares of China, the first puzzle magazines in the 18th century, the 19th-century American crazes (when pros began to make a living at it), and the 200 million Rubik's Cubes sold in the 1980s. Enigmas, charades, riddles, anagrams, cryptograms, rebuses, duck-rabbit images, mathematical brain-crushers, Chinese tangrams - all get their moment of shrewd scrutiny. At the same time, Danesi pauses frequently to work through a formidable (and often historic) example, such as German mathematician Leonard Euler's "Konigsberg Bridges Puzzle." ("In the town of Konigsberg, is it possible to cross each of its seven bridges over the Pregel River, which connect the two islands and the mainland, without crossing over any bridge twice?") If you like these sorts of things, they make stimulating rest stops. Neglecting the downside Puzzles, Danesi maintains, provide "comic relief" from "the angst earned by the unanswerable larger questions. ... Since there are no definitive answers to the large-scale questions, we are strangely reassured by the answers built into the small-scale ones." What, however, about folks who see that quid pro quo for what it is, and consequently find solving "artificial" puzzles boring and pointless? The sole weakness of Danesi's otherwise splendid study is an almost tone-deaf neglect of the downside of puzzlemania. But Danesi is entitled, given the spadework of this book, to write like the enthusiast he is. Aficionados of cerebral workouts need look no further for autumn kicks. Puzzle skeptics, however, will leave unpersuaded of the uncanny rush that comes from solving a problem that needn't be solved. It remains a mystery.

Graphic: THE PUZZLE INSTINCT, by Marcel Danesi. Hardcover. 269 pages. $25.95