HOW MONKEYS SEE THE WORLD; Inside the Mind of Another Species By Dorothy L. Cheney and Robert M. Seyfarth University of Chicago. 377 pp. $24.95

"WHEN WE watch nonhuman primates and analyze their behavior, do we have their minds or ours under the microscope?"

Thus do Dorothy Cheney and Robert Seyfarth pinpoint one of the great practical -- and philosophical -- dilemmas of trying to understand the workings of minds other than our own. Eons of evolution have fashioned the human mind to build models of a certain reality. As a result, we analyze and predict the behavior of our relatives, friends and strangers, based in part on subjective introspection, on what we know about ourselves.

It is difficult to escape the thrall of this cognitive trick. The result is the seductive tendency to anthropomorphize: the dog "misses" its absent master; the cat is "jealous" of a new pet; and so on. We attribute to the cat, the dog, maybe even a plant, feelings we would experience ourselves in similar situations.

Cheney and Seyfarth have been studying vervet monkeys for years, in Amboselli National Park, Kenya, trying to look into the minds of these animals, our relatively close relatives. "Anthropomorphizing works," they say. "Attributing motives and strategies to animals is often the best way for an observer to predict what an individual is likely to do next." Naturally, though, Cheney and Seyfarth are deeply suspicious about what this actually means about the monkeys' mental world as compared with ours.

In How Monkeys See the World these two primatologists at the University of Pennsylvania report their careful experimental probing of vervets' minds, and discourse on the nature of the human mind. The book mixes field reports -- of how they monitored social interactions and dissected the animals' range of vocal communication -- and a theory of mind. Their aim, they explain, was to demonstrate that "the social behavior of nonhuman primates offers a glimpse of almost minds at work -- a glimpse that may ultimately tell us how, in the course of our own evolution, some minds gained advantage over others."

"Almost minds" is an odd concept to grapple with, only because we are saddled with the workings of our own mind, in which the phenomenon of consciousness blazes so brightly as to be mentally blinding. What of the vervets and other nonhuman primates? "Resolving the role of consciousness in animal thinking would be much easier if there were some agreement about its role in human thinking," lament the authors. Their discussion of the dilemma is as enlightening as one could hope to find in either the scientific or philosphical literature.

When they describe their work on the vervet's social realm, Cheney and Seyfarth show clearly how inadequate is the popular view of rigid hierarchies as the pattern of interaction. "It is not enough to know who is dominant or subordinate to oneself," they say, "One must also know who is allied to whom and who is likely to come to an oppenent's aid." The name of the social game is the establishment of alliances, and the close monitoring of the overall network of allegiance.

Among thir peers, Cheney and Seyfarth are perhaps best known for their research on vervet communication. The alarm calls of vervets -- which are different for eagles, snakes and leopards -- have been well studied, but here one learns of some subtleties that make the system seem much less rigid than is commonly imagined. For instance, on one occasion a monkey was about to be snared in the talons of a swooping eagle, when a companion gave a leopard-alarm call, not an eagle-alarm call. A mistake, reflecting a moment of intense fear? Or intentional, because the normal response to an eagle alarm would be to look to the skies, a sure recipe for death in this case, whereas a vervet's reaction to a leopard alarm is to run like crazy, a route to safety in this instance?

In their deeper analysis of other calls -- social grunts -- Cheney and Seyfarth discovered an unexpected breadth of modulation, which, presumably means something to the animals. "From an observer's perspective, watching monkeys grunt to each other is very much like watching humans engaged in conversation without being able to hear what they are saying," observe the authors; "the creatures seem to be exchanging some sort of information, but we have no idea what it is."

To observations on vervet social interaction and vocal communication, Cheney and Seyfarth add a study of deception, because, in order successfully to deceive, one must be able to look into the mind of another individual as it might perceive oneself. "While they do attempt to deceive each other," the authors conclude, "monkeys' attempts at deception seem aimed more at altering their rival's behavior than at affecting their rival's thoughts." "Almost minds" at work?

Although anthropomorphizing often works in predicting vervets' behavior, Cheney and Seyfarth conclude that these monkeys' minds fall short of ours: "Compared with our relatively full, coherent picture of human social relationships, the vervet monkey's view of relations among other vervets seems like Picasso's cubist guitar: many of the parts are there and some of them even fit together, but the elements are in disarray and the net effect is that of a puzzle that has not been assembled correctly."

For an exploration of the puzzle of mind and a vicarious experience of a careful experimental quest, How Monkeys See the World is surely unsurpassed. Make no mistake: This is a serious work of science, not a collection of charming anecdotes. But the ideas are so enthralling, the language so lucid and lyrical and the presentation so captivating, that the challenge of the book to the non-primatologist is well worth the effort. This reviewer had to be restrained from stopping people in the street to urge them to read it: They would learn something of the way science is done, something about how monkeys see their world, and something about themselves, the mental models they inhabit. Roger Lewin is the author of "Bones of Contention." He is finishing a book, coauthored with Richard Leakey, on human origins.