Watching a dog’s excitement at taking a walk or seeing pigeons gather every day at the same time at a park bench where an old man tosses them bits of bread, we may wonder how animals perceive the world. What do they know? Do they think? Do they feel as we do?

Almost every pet owner can tell a story about Fido’s sadness at being left alone and his joy at having a partner in play. And increasingly biologists studying wild animals can tell stories too. Consider a couple of anecdotes from Jeffrey Masson and Susan McCarthy’s recent book, When Elephants Weep: The Emotional Lives of Animals. In Kenya several baby elephants watched as poachers killed their parents and cut off their tusks. The young elephants were taken to an animal orphanage, where they regularly woke up in the night screaming. One of the young chimpanzees Jane Goodall studied in Africa wouldn’t leave his mother’s body after she died. He spent a great deal of time staring at the sleeping nest the two had shared before her death, grew listless, and died within a month.

For millennia philosophers have been pondering just what’s going on inside animals when they behave like this, but the issue has been subjected to only a modest amount of serious scientific inquiry–inquiry that has often been tainted by political considerations. Charles Darwin made one of the first attempts in 1872 with The Expression of the Emotions in Man and Animals, a book whose impact was surely lessened by his publication the previous year of the extremely controversial The Descent of Man, in which he posited an evolutionary link between humans and primates. Critics of that book labeled as blasphemous and absurd his theory that humans are descended from and subjected to the same evolutionary pressures as a long line of primates. The critics claimed a special provenance for human beings.

By the end of the 19th century most scientists had come to accept Darwin’s theory, though they still rejected any idea that humans were on the same plane as animals. Humans might be products of evolution, but somewhere along the line we’d gained unique abilities to feel and to think, while animals remained products of instinct, were practically automatons. Yet the American public never fully agreed. As the buffalo slaughter on the Great Plains ended and the last passenger pigeons fluttered into extinction, an increasingly urbanized America began romanticizing the nature it had recently faced as an adversary–just as it had transformed the defeated Indians from godless, formidable enemies into noble savages.

By the turn of the century men like John Burroughs, Ernest Thompson Seton, and William J. Long were making small fortunes writing best-sellers that proclaimed the virtues of nature and of wild animals. Then in 1903 they had a falling out. Burroughs attacked Seton and Long, claiming that some of the things they described–such as a porcupine that curled into a ball and rolled downhill for fun–were simply tall tales. Burroughs wrote in the Atlantic that animals were “almost as much under the dominion of absolute nature, or what we call instinct, innate tendency, as are the plants and trees.”

The debate over whether animals were living machines, as Burroughs believed, or thinking, feeling individuals, as Seton and Long shot back, swirled through magazines and editorial pages for a few years. In 1907 President Theodore Roosevelt sided with his good friend Burroughs, saying, “I don’t believe for a minute that some of these men who are writing nature stories and putting the word ‘truth’ prominently in their prefaces know the heart of the wild things.” He dubbed Seton and Long “nature fakers,” and singled out for particular ridicule a story of Long’s about a wolf that killed a caribou by piercing its heart with its teeth. Roosevelt–who was not only America’s best-known conservationist and amateur naturalist, but also a notoriously enthusiastic hunter–was stung when Long snapped back, “I find after carefully reading two of his big books that every time Mr. Roosevelt gets near the heart of a wild thing he invariably puts a bullet through it.”

Most scientists agreed with Roosevelt. Researchers like Ivan Pavlov and B.F. Skinner followed in Roosevelt and Burroughs’s footsteps, propounding behavioralist theories that ascribed animal behavior to genetics, to conditioning–to anything but thinking. If animals appeared to have emotions, it was because human observers tended toward anthropomorphic explanations for instinctual behaviors. Such behavioralist thinking prevailed through most of this century among scientists, even though in the popular culture animals were increasingly accorded a place that, if not quite on a level with people, was certainly not that of purely instinctive automatons. From Bambi to Lassie, animals entered our theaters, homes, and psyches as passionate, feeling individuals. As stars, even.

This split between science and public perception still persists. For example, controversies about animal rights pit activists interested in the fate of individual animals against scientists who say that individual animals need to be sacrificed in the pursuit of a higher good. Whether these scientists are conservationists who propose to preserve the health of Illinois woodlands by shooting deer whose increased numbers are destroying native wildflowers, or medical researchers who claim they can save human lives by performing tests on laboratory animals, they have often been criticized far more vitriolicly than Roosevelt ever was.

Scientists are partly to blame for that. Most biologists and psychologists–even those who might disagree with the behavioralists–have been reluctant to explicitly research questions about feeling and cognition in animals, in part because of the well-founded worry that those who do will be accused of anthropomorphism or sentimentality by their colleagues. In the 1980s a few researchers began examining whether animals possess intelligence as humans do, and Skinner groused, “I think this cognitive thing is a fad, and psychologists go in for fads….I think it’s about time for this one to fade out.”

Their reluctance also stems from the institutional structure of biology. Studies and publications are refereed largely according to what can be proved or turned into statistics. It’s not too difficult to apply that standard to animal behavior–when presented with stimulus A, the chimpanzee responded with a particular behavior x percent of the time–but researchers have understandably had trouble applying it to what the animals think or feel while engaging in that behavior. It’s difficult enough to explicate what other people are thinking or feeling; how are we to come to terms with what goes on in the minds of animals?

Nevertheless, the last two decades have seen a rising tide of research and publications devoted to examining both animal cognition and emotions. Some researchers have bucked considerable criticism to start projects aimed at deciphering the mental states of animals such as captive dolphins and chimpanzees. Other biologists engaged in long-term studies of wild animals–Jane Goodall watching chimpanzees, Cynthia Moss trailing African elephants–have accumulated reams of information about the intellectual and emotional lives of their subjects, and have the scientific clout to write about them without being laughed out of the institution.

This research is the subject of When Elephants Weep. Author Jeffrey Masson, a psychoanalyst, is no stranger to controversy. He created a stir in 1981 when, as director of the Sigmund Freud Archives in London, he claimed to have discovered that Freud had covered up his findings about child sexual abuse. Two years later Masson sued New Yorker writer Janet Malcolm, alleging that he was relieved of his post at the archives because her profile of him misquoted him; a decision last year cleared Malcolm of wrongdoing and left Masson liable for court costs, but he’s appealing.

Here he and Susan McCarthy, a science writer, present an exhaustive polemic on animal emotions, drawing not only on recent research, but on anecdotal observations by zookeepers, pet owners, and hunters. They heap study upon study, anecdote upon anecdote, each indicating that animals feel emotions, or at least raising the possibility that they can.

Much of this evidence is persuasive. How else are we to interpret Moss’s tale of elephants circling a dead companion and eventually dropping vegetation on its body if not as demonstrating some kind of sorrow? How are we to explain bison running onto a frozen lake and spinning around on the ice, then returning to shore to start over, if we don’t concede that they may be experiencing the pleasure of play? How can we explain why pilot whales have been seen rescuing a harpooned companion, at no small danger to themselves, without admitting that they may be compassionate and altruistic?

All these stories are haunting, if occasionally tedious, though some of the authors’ speculations about them will make biologists roll their eyes. Masson and McCarthy suggest, for example, that animals may feel “counterphobia,” a condition in which people seek out the very things they most fear, albeit unconsciously. In defense of this idea they quote a biologist who reported that “deer have a marked objection to allowing any person or object out of their sight which they may think to be a source of danger.” But biologists wouldn’t call this counterphobia; they’d call it a basic evolutionary adaptation to the animal’s ecological role–the deer that loses track of a wolf’s whereabouts is more likely to be caught and eaten.

In seeking to blur the line separating humans from animals, Masson and McCarthy also blur the lines separating types of animals. In examining the possibility that a mother spider may feel love, they gloss over numerous experiments that have shown–as far as scientists have been able to tell–that life in the arthropod world truly does seem to be ruled by instinct. Genetics and behavioral observations should both tell us humans and chimpanzees have a lot more in common than chimpanzees and spiders.

Still, the theory of evolution has become accepted to such an extent that biologists now seem to want to explain every aspect of animal behavior in evolutionary terms. If grief can’t readily be explained as a quality that helps an animal pass its genes on to another generation, many biologists are apt to ignore or discount it. And biologists have been extremely conservative about admitting that emotions–grief, love, compassion–may confer survival value, perhaps in ways we don’t understand. Masson and McCarthy are right to criticize this conservatism, but their speculations about counterphobia and spider love leave the reader wondering whether they’re not practicing the same thing in reverse–creating a complex psychoanalytical explanation when a simpler one would seem more plausible.

Given how little we know about animal emotions, it’s no wonder that Masson and McCarthy are often reduced to negative arguments. Maybe we can’t know for sure that animals feel certain emotions, they argue, but then we also can’t know for sure that they don’t. They ask about the way an ape cares for her baby, “If it is called instinct, does that mean no feelings of love can also be there?” And they write, “It is hard to imagine playing with an ant, but this is no reason to decide that ants cannot play with one another.” And, “It does not necessarily follow that if animals do not blush, they do not feel shame.” This is a psychoanalytical approach to biology: if we could just feel more deeply, we would get in touch not only with ourselves, but with the entire animal kingdom.

The accumulated weight of anecdotes and observations is the way we learn about the world. A dog owner learns about her pet’s state of mind by observing its behavior through the years. The reader of When Elephants Weep finds himself slowly overwhelmed by tantalizing hint after tantalizing hint that animals do feel emotions, even if no one can quantify them or prove they’re the same as our own.

It would be a callous reader who didn’t feel those hints inciting a slow burn of anger at the examples of cruelty to animals cited here. This book follows in the wake of other tracts, such as Peter Singer’s Animal Liberation, that argue for an end to human abuse of animals. When Elephants Weep barely touches on the issue of meat eating and is somewhat ambivalent about keeping animals in zoos, but it serves up an unsparing critique of animal experimentation. Masson and McCarthy cite several horrific examples of laboratory tests, among them an experiment detailing the degree to which monkeys become antisocial when they’re raised in an isolation chamber. Such an experiment serves to “prove” what simple common sense would tell most people.

But outright abuse is only the most obvious dereliction of science illustrated here. Many field biologists are more aware than most that animals have experiences and perhaps emotions beyond what we can explain, but they’re still largely prevented from saying so in professional publications, because of pressure from peers and funding agencies. Writer Barry Lopez has hinted at what’s often missing from published research in an anecdote about a trip he took with one biologist: “One morning, walking through fresh snow, looking for mountain lion tracks on the north rim of the Grand Canyon, a biologist with years of this behind him said to me suddenly, ‘It’s not in the data.’ I looked at him. ‘It’s not in the data,’ he reiterated. With his hands he made a motion to indicate his head, his chest. ‘It’s here. What I know is here.'”

Forced to omit what they know, biologists enlarge the gap between them and members of the public. And they emphasize the distance between people and animals rather than what we have in common. In an era when ecosystems everywhere are under siege and the space available for wild animals shrinks daily, this attitude is irresponsible.

It’s good to read that researchers like Goodall and Moss are breaking the old molds. But what When Elephants Weep ultimately demonstrates is that questions about our dealings with other animals–questions that may help us to better understand the strange animals that we are–are too important to be left to scientists alone. It’s going to take a lot of work to ensure that future generations can enjoy as much of the natural world as we do, and that will happen only if we acknowledge that the natural world has value in ways that science can’t now explain and probably never will be able to explain. Getting near the heart of wild things is an undertaking that requires not only our intellect, but our heart.

When Elephants Weep: The Emotional Lives of Animals by Jeffrey Moussaieff Masson and Susan McCarthy, Delacorte Press, $23.95.

Art accompanying story in printed newspaper (not available in this archive): illustration/Jim Flynn.