American Scientist

Clever as a Fox: Animal Intelligence and What It Can Teach Us About Ourselves. Sonja I. Yoerg. ix + 228 pp. Bloomsbury, 2001. $24.95.

Clever as a Fox is an attempt at "an objective analysis of what we do and do not know about animal intelligence." At issue is comparative animal cognition—the ranking and comparison of animals to one another on the basis of the psychological construct we know as intelligence.

Author Sonja Yoerg considers the difficulty not just of defining, but of measuring and ranking intelligence. How do we know that the "intelligent" behavior we observe in animals isn't simply the result of a complex reinforcement history to which we are not privy? What evolutionary forces have created the premium on intelligence—the need to socialize in same-species groups? Or to go out every day in search of variety in comestibles?

Yoerg makes the following points in defense of the study of animal intelligence: It is reasonable to hypothesize that intelligence, which evolved as a cognitive strategy in humans, evolved similarly in other species; the study of general abilities such as intelligence should help us see the "big picture" with regard to cognition; and an evolutionary perspective on how other species benefit from broad intellectual capacities should prove useful.

As the owner of two intelligent German shepherd dogs, I find that I often attribute to them human mental states such as wonder, jealousy, anger and even concern. I do not, however, do this with my pet lovebird. Why not? Why project human emotions onto dogs and not lovebirds? And what is the smartest animal, anyway?

Yoerg, whose training is in biological psychology, suggests that our answers depend on which animals are closest to us, and perhaps on whether the animal is too neotenized—juvenile in appearance—or too "cute" for us to perceive it as smart. And whereas I think my shepherds are at the head of the class, the Bororo Indians of Brazil might nominate the macaw, and the Gujarati sheep herders of India would name their sheep. So culture, too, has an influence on how we view intelligence in animals.

Although the book is intended for a popular audience, it is not primarily anecdotal. Yoerg brilliantly dissects the dense literature in experimental animal cognition. Several classic and some more obscure research studies are examined. The psychological school of behaviorism suffers a well-deserved trouncing every few pages.

In the book's 10 chapters—which have such deceptively playful titles as "You Can Lead a Horse to Water, But You Can't Make It Think"—Yoerg leads us through many intricate field and lab experiments on birds, rodents, nonhuman primates, dolphins and other animals. The book is difficult to skip around in, since the chapter headings and subheadings do not immediately give a clear idea of what is discussed. Often, only after reading a section does the heading make sense, and then its aptness becomes clear.

This book is notable for its readability, erudition and use of metaphor. Yoerg is witty, opinionated, quite funny and much more clever than even the brainiest fox. Although she provides no definitive answer to the question of how to create a general test of animal intelligence (or the question of whether animals even have such a thing as general intelligence), we come away satisfied that we do not need such a test after all.—Evangeline A. Wheeler, Psychology, Towson University