One wintry day in 1979, high in a mountain wilderness overlooking the ancient city of Kyoto, a zoologist studying monkeys that live in this refuge was startled by a peculiar sight. A young female had carried several flat stones from the forest. She stacked them and then, using the palms of her hands, knocked and scattered them. Far from "normal" monkey behavior, this was quite unlike the usual practices of foraging, grooming and mating. This animal was playing, much as a human child would play. The scientist concluded his field work the next year, having seen no other instances of monkeys playing with stones. But when he returned in 1983, the behavior was common. He frequently saw monkeys spend as much as 20 minutes engrossed in any of a dozen or more different "games" such as rubbing or clicking stones together, piling rocks or pebbles into mounds or cuddling a large stone to the body as if it were a baby. Even infants as young as two weeks would try to join in. Stone handling had become routine among monkeys in the two troops here, 175 animals in one and 120 in the other. The monkeys of Arashiyama are Japanese macaques, also known as snow monkeys because they live farther north than any other monkey species, routinely encountering snow in winter in the northern parts of the Japanese island of Honshu. Japanese researchers have been studying the free-living monkeys for many years, often encouraging them to visit observation sites by providing food. Long before Western scientists adopted the practice of observing a single colony of animals for a long time, Japanese researchers had developed it to a high level, even learning to identify individual animals and following their behavior daily for years. As a result, they discovered something profound. Animals such as the stone-handling monkeys have a culture -- behaviors that are not based on instinct or required for biological reasons but whose patterns are invented in specific regions and passed by teaching or imitation from one generation to the next. Such intensive studies were possible because, to do field work on the Arashiyama troops, for instance, requires no costly expeditions to faraway continents, just a 40-minute train ride from downtown Kyoto. Other monkey habitats are no farther than the southern island of Kyushu. Having their subjects almost in their backyard has enhanced the ability of Japanese primatologists to perform their pioneering and detailed genealogical studies. The Japanese macaque weighs about 25 pounds and has light brown fur, with a red face and buttocks reinforced by calloused pads that allow it to sit comfortably on the rockiest crag. A relatively common wild mammal here, it is distributed across the main island of Honshu, as well as the southern islands of Shikoku and Kyushu. A subspecies, the Yaku Shima-zaru, which is gray-colored, lives on the tiny southern island of Yaku Shima. The notion of non-human culture is relatively new in the Judeo-Christian West, where the tradition has been to rank all beings on a ladder -- Gods above humans and humans above the other animals. In Japan, however, where the Buddhist-Shinto world- view not only reveres nature as sacred but also places people and nature on equal footing, scientists routinely assume that macaques can think and create cultures of their own. While Japanese biologists accept Darwinian evolution, many reject the Western notion that every aspect of primate behavior must be understood as a product of natural selection favoring behaviors that confer a tangible benefit. The Japanese focus has been a sociological, rather than biological, approach to uncovering the lives and social organization of primates. "Japanese are not constrained by the idea of a hierarchy, metaphorical or otherwise, in nature, nor the question of whether animals have a mind or soul," writes Pamela J. Asquith in The Monkeys of Arashiyama. "Animal minds and souls are assumed to exist -- they are simply different {from} those of humans." "Japan's big contribution {to primatology} was anthropomorphizing to a degree and asking those questions: What's this monkey thinking? What's on his mind?" says Michael Huffman, an American zoologist based in Kyoto. Huffman was one of the first researchers to document stone handling. "Japanese have always interpreted the animal from their perspective, without stepping out of the bounds of acceptable science." "Out of bounds" is just how mainstream Western researchers branded Japan's pioneering primatologist, Kinji Imanishi, in 1952 when he announced that his team had learned to identify every member of a troop, from boss male to tiniest infant, by physical characteristics, personality and ancestry. "People didn't understand this, didn't think it was objective enough," Huffman says. "Everyone thought it was impossible." Once individual identification was possible, distinct societies gradually came into view. Adult males in one troop were found to be great fathers, while males in other communities left parenting entirely to mothers. A troop living near Osaka savored certain tubers and bulbs that were hated by monkeys of the same species in other parts of Japan. Some communities fed on unhusked rice; others wouldn't touch it. Pioneer primatologists Junichiro Itani and S. Kawamura reported several examples of novel behavior in the 1950s, notably washing of food provided by researchers. In 1953, for example, on the southern island of Ko Shima, a monkey named Imo was seen carrying dirty sweet potatoes to a stream and washing them before eating, a practice the rest of the troop soon adopted. After researchers began leaving wheat on the beach, the monkeys discovered a technique for sifting the grains by tossing handfuls of sandy wheat in sea water. The sand sank, but the wheat floated and could be scooped up. Much early Japanese research on such behaviors was dismissed in Europe and the United States. The "Japanese made many discoveries, couched in anthropomorphic language and hence ignored by Westerners, before Westerners paid attention to the complex social side of primate lives," says Asquith, who noticed that several findings published as new discoveries in Western journals of the 1970s and 1980s had been documented by the Japanese years earlier.

She recalls two times when Western colleagues mentioned that, during their graduate studies, they "did not dare" quote from Japanese findings because the research was considered flaky. Japanese research also challenged a Western assumption about sex roles. Western researchers had argued that males developed relationships with females purely to mate and that females complied to receive protection from the stronger male. This view reflected the bias of observers and the fact that male behavior is easier to see. Indeed, early studies on rhesus macaques and baboons in other parts of the world seemed to bear out this pattern. But Arashiyama's trove of data, the oldest and most comprehensive primate genealogy in the world, proved that their females have a big say about mating. After about two years, for example, a female may reject the sexual solicitations of a male with whom she has mated. After their initial sexual relationship, macaque couples appear to form a platonic bond. The pair feeds and grooms together, and the male helps the female in winning conflicts, gaining access to food or rising in the hierarchy. But the female has sex with other males. Some males even prefer friendships with a close female relative, who are unlikely mating partners. Such details would not have been documentable without individual identification of the animals. This also has led to the discovery that there is little correlation between female rank and number of offspring, a finding that causes researchers to wonder about the purpose of a hierarchy. The ability of females to determine with whom they conceive amazed even Japanese scientists, such as Juichi Yamagiwa of the Primate Research Institute in Inuyama. "I always thought the monkey troop was like a Japanese company, with a tough boss and subservient females," he says. "But then I saw females mating with {lower-ranking} males from outside the troop." Among Japanese monkeys, it turns out, females are the group, since males are itinerants, joining a troop for a few years and then leaving to wander or join another troop. Thanks to DNA "fingerprinting," rank has been found to have only a weak correlation with paternity. The Arashiyama studies have helped to change our concept of non-human primates, from dumb beasts acting purely on instinct to animals that think. Witness the case of "Deko 64," one of the most cherished macaques studied at Arashiyama. Deko was the highest-ranking, or alpha, male of E troop for six years until he grew old and weak and died in 1992. He was an extraordinarily benevolent leader, protective of even the youngest members of the troop. For example, when a female carelessly left her baby in front of him, Deko amazed observers by not doing what typical dominant males would do -- biting or swatting the young monkey away. Instead, he cuddled and groomed it as gently as the mother would have. Over the years, Deko grew old and lost his rank. Outside the well-documented fields of Arashiyama, a researcher might have expected that he would be treated with diminishing regard. Instead, his earlier kindness was repaid. Some females who had been associated with him for many years stayed close to him when he was very old, weak and unable to see well. They chased away young males who attempted to threaten or attack him. The females remained with him until he died. The unusual custom of washing food has been documented more recently in other monkey species, including wild and hand-reared crab-eating macaques and in lab-dwelling capuchin monkeys. Tool use and toolmaking by wild chimpanzees has been observed widely and is the most distinctive cultural behavior of that species. But all of these behaviors could be interpreted as functional, helping to obtain food or making it tastier or easier to eat. Stone handling is harder to explain. It is the first recorded instance of a new animal behavior with no apparent usefulness. Huffman speculates that the innovation sheds light on how our primitive ancestors transmitted culture, activity adopted not for practical reasons but simply because it was fun or relaxing, and the "in" thing to do. Interestingly, stone play appears to be a luxury of the "affluent." It is rarely observed in monkeys that are not being given food and must spend most of their waking hours searching for something to eat and processing it. While zoologists say it is highly unlikely that any monkey species would learn to manufacture stone tools, the unusual phenomenon of stone play does suggest how, given the right environment, such a cultural leap might occur. Lucille Craft is a freelance writer based in Japan. CAPTION: Overcrowded, Macaques Came to America In recent decades, the range of Arashiyama's monkeys has shrunk from about three square miles to less than 0.4 square miles, largely because of "provisioning" the monkeys with food. If they must find their own food, macaques typically range an area as large as five or six square miles, searching for seeds, fruits, bark, leaves, insects and shellfish. Troops usually include several score members, who live under a strict hierarchical system. A group of males and females dominates the troop, followed by many lower ranking young males, who leave the troop after two to five years. Japanese macaques typically live about 25 to 30 years, and females bear an average of five young. Unprovisioned macaques spend about one-third of their waking hours foraging; the rest of the time, they move between feeding grounds and resting places. One distinguishing feature of the Japanese macaque is its adaptability. This was demonstrated most vividly in 1972, when Arashiyama became overcrowded, forcing researchers to find an alternate sanctuary in North America. The search began in Missouri and Michigan, where the land and climate resemble those of western Japan. But a funding shortage led the scientists to accept land donated by a rancher in Laredo, Tex., and about 150 members were resettled in "Arashiyama West." Some people feared that plopping Japanese monkeys into a strange new world of semidesert brushland plains, with poisonous shrubs, predatory bobcats and rattlesnakes, would be lethal. But after a short adjustment, the monkeys thrived again. "Japanese macaques are the most generalized kind of monkeys," says Yukimaru Sugiyama, who has studied primates worldwide for 35 years. "Wherever you take them, they can survive." CAPTION: A Japanese macaque, member of a species that intrigues scientists by developing local cultural traditions. CAPTION: A Japanese macaque indulging in the local tradition of playing with stones. CAPTION: Japan is about as northerly as the United States, placing its monkey populations in a climate comparable to that of the American Midwest. CAPTION: A top-ranked, or alpha, male, right, commandeers food provided by researchers in a clearing at Arashiyama. Below, a macaque family huddles for warmth. Below right, a mated pair surveys the scenery in its snowy, mountain refuge.