In the prologue of his new book, The Ape and the Sushi Master, Frans de Waal asks you to "imagine a family of elephants watching a television show in which people have hoses strapped to their noses and try to use the appendage to pick up a coin or uproot a small tree." The humans trip over their "trunks" and repeatedly demonstrate how "ineptly unelephantine they are," de Waal says. "I don't think we would find the show particularly funny, certainly not for longer than a couple of minutes, but an elephant family might never get enough of it." The notion of such a show seems absurd, but imagine a group of humans watching a television show in which chimpanzees, cutely dressed in suits, act like humans perhaps by sitting around a table playing cards or having tea. As long as the chimps aren't too good at their human imitation, we can laugh.

"By allowing animals to mock us, we let them make even greater fools of themselves, which permits us to laugh away any doubts we might harbor about ourselves," de Waal says.

The issue involved in these examples, de Waal notes, "is not humor, but self-definition." And what defines humans, what makes us truly different from all other animals, is culture, he says. "We define ourselves as the only cultured species, and we generally believe that culture has permitted us to break away from nature."

While De Waal, a renowned primatologist and ethologist, doesn't doubt the important role of culture in defining humans, he also doesn't believe culture is unique to our species. The title of his book, The Ape and the Sushi Master, is a summary of de Waal's view. Preparing sushi is a cultural exercise, he says, and it is learned not so much by direct teaching but through years of quiet observation by apprentices. The same process is at work among other primates, de Waal says, and in other species as well.

"Cultural diversity in the animal kingdom probably takes on vast proportions," he writes. In arguing that there is overwhelming evidence of culture in other species, especially primates, de Waal shows little patience for those who disagree, primarily "behaviorists" who grant a "mental life" to humans but keep animals in the category of "stimulus-response machines."

Cultural diversity among animals is the central argument of his book, and de Waal hammers it hard, with example after example interwoven with the book's other story, the development of research into the "cultural" aspects of nonhuman primates. His critiques of behaviorists, scattered throughout the book, drip with contempt.

De Waal cites a well-known experiment, reported in 1970 by psychologist Gordon Gallup, which found that chimpanzees were self-aware when they looked into a mirror. Gallup painted a dot on the face of an anesthetized chimp and, when the ape awoke, gave the animal a mirror. "In these experiments," de Waal writes, "the ape would stare at the dot in the mirror, then bring a finger to the real dot on its own face and inspect the finger afterward, a clear sign that the animals linked their reflections to themselves."

Behaviorists repeatedly attacked the experiment as not showing self-awareness or, if it did, that self-awareness was nothing special. The critics didn't bother to study chimps or any other primates, de Waal says, but developed theories based on preconceived notions about the difference between humans and other animals. "Behaviorists really do believe that they can generalize from rats and pigeons to all other species," de Waal says. Calling the behaviorist view "pre-Darwinian," he says it "ignores the fact that every animal is a unique product of natural selection in both body and mind."

The view that animals are lesser beings, without culture, stems from the Western religious tradition that places humans above the animals, de Waal notes.

The Ape and the Sushi Master is more than a prolonged argument for the elevation of animals, however. In making his case, De Waal takes the reader on an interesting tour of animal behavior that reflects what he sees as the influence of culture in animals. Of course, there is Binti-Jua, the gorilla mom whose 1996 rescue of a boy who fell into her enclosure at Chicago's Brookfield Zoo made international headlines. There is also the 50-year-old potato washing habit that spread among Japanese macaques on Koshima, and the two dogs in Thailand who raised three tigers and now share a cage in a zoo with the full-grown cats.

De Waal also talks about the behavior of the scientists who laid the foundation of what was to become ethology - the "scientific study of animal behavior." In a chapter titled "The Fate of Gurus," de Waal notes that scientific leaders, like aging silverback gorillas, are inevitably challenged and replaced by a new generation of researchers.

His primary examples are Kinji Imanishi, a renowned Japanese primatologist who died in 1992, Niko Tinbergen, a Dutch ethologist, and Konrad Lorenz, author of the 1963 book On Aggression, in which he argues that humans are by nature violent. Lorenz was a brilliant thinker who clearly influenced de Waal. But Lorenz was also a Nazi sympathizer during the late 1930s who "repeatedly called for a deliberate, scientific race policy in order to improve . . . race through the elimination of defective and inferior elements," de Waal writes.

The ideas of these founders, as profound as they were in their day, have been overtaken by younger scientists who first attacked the earlier work, then moved beyond it. The same thing is happening now to Stephen Jay Gould today, de Waal notes, as young scientists challenge Gould's view of evolution.

De Waal's has woven together primate research history, his own field observations, and the work of other scientists into a book that builds a convincing case for development of culture in many species. "The time has come to define the human species against the backdrop of the vast common ground we share with other life forms," de Waal concludes. "We and other animals are both similar and different, and the former is the only sensible framework within which to flesh out the latter."