February 2005
| R E V I E W |
Can Dogs Think? |
WHERE IS THE DOG OWNER who hasn't wondered just what might be going on in that canine head? Those who train dogs professionally are certainly moved at times, in moments of frustration, to doubt that anything is going on in there at all. If dogs are so smart, why can't more than a small percentage make it through training as agility dogs, customs dogs, guide dogs, or obedience dogs, to perform reliably at tasks that seem quite straightforward?
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Even animal experts, who are supposed to know better, can find it hard to resist the temptation to explain canine behavior with fanciful “just so stories.” Dog stories almost invariably imply that the dogs in question can think—and think like people.
But stories are one thing, science another. In science, the best one can do is observe the behavior of dogs in natural and controlled settings, and then, on that basis, make testable inferences about canine cognition. Yet despite the popularity of dogs—or maybe, in large part, because of it—the scientific investigation of canine behavior and cognition has lagged far behind that of many other animals. The reasons are not hard to fathom. Ethology, for instance, is the study of the behavior of animals in their natural habitats, but for domesticated canines, the “natural habitat” is the somewhat artificial one people have created. Another reason for the dearth of scientific studies is the deep emotional bond between dogs and people, which poses a constant challenge to the objectivity of the investigator. Particularly when people's tendency to anthropomorphize their dogs is coupled with such thorny concepts as “mind” and “thought,” the need to be aware of unconscious bias and unfounded interpretation is paramount.
Two recent books tackle the problem head on. In How Dogs Think: Understanding the Canine Mind, Stanley Coren, a psychologist at the University of British Columbia and a noted author on dog-human interactions, concludes that the scientific evidence just doesn't support ascribing humanlike mental activity to dogs. In If Dogs Could Talk: Exploring the Canine Mind, Vilmos Csányi, an ethologist at Eötvös Loránd University in Budapest and a noted dog expert, seems equally convinced of the opposite conclusion.
Most dog books fall roughly into two types: the ones that focus on training, and the ones that tell dog stories. And though Coren and Csányi serve up healthy portions of both, they also strive mightily to go beyond those formulas and report what rigorous research has to say about whether dogs have minds and can think—and, if so, to what degree they think like people.
Coren begins his book by tracing the history of the concept of mind as applied to canine cognition—what he calls “the battle between ‘dog as thinker’ and ‘dog as machine.’” In Coren's account, philosophers such as Plato and Diogenes exemplify the former, whereas strict behaviorists such as B.F. Skinner insist on the latter. Expert opinion then just swings back and forth between these two poles like a pendulum.
Is the field of canine cognition doomed forever to repeat this seemingly endless dispute? In his book Wild Minds: What Animals Really Think, Marc D. Hauser, a psychologist and neuroscientist at Harvard University, suggests a different approach. Hauser sees an animal's ability to solve problems—to act intelligently—as indicating that it possesses a set of “mental tools.” Those tools arise out of a complex interplay of genes, development, and learning. Hauser further suggests that, to the extent a species faces specific problems, its tool kit may include unique or specialized tools, of greater or lesser quality, that do not occur in the tool kits of other species. Species specialization does not make one species “smarter” than another, according to Hauser, just “wonderfully different.”
Applied to dogs, Hauser's approach cuts through the vague but passionate disputes about whether dogs think, or just act like robots. Instead, he suggests that research focus on relatively straightforward comparisons between the mental tools deployed by various species. For example, how well do dogs compare with other species in remembering objects that are out of their sensory range? This mental tool, known as “object permanence,” presumably must be brought to bear if a dog is to answer that age-old question, “Where is your ball?” Mental tools that deal with object permanence, as well as counting, mapmaking, knowledge about the nature of objects, and on and on, help an animal solve problems such as where to find hidden caches of food.
How does this talk of toolboxes apply to people? Humans have special mental tools—a “theory of mind,” for instance—that help them solve “psychological problems” such as “What is that person thinking?” Other tools open up cognitive possibilities such as consciousness, self-referential behavior, and language. One key point to emphasize is that possessing a given mental tool says nothing about how the tool works. It implies only that an animal possessing it can perform the information-processing necessary to solve a particular problem.
For Hauser, the concept of “mind” is shorthand for the mental tool kit an animal possesses. Hauser generally avoids the terms “thinking” and “consciousness” as unnecessarily vague and unhelpfully reliant on human-centered actions. His point is that, though people usually insist they know what such terms mean, the terms have not even been defined as they apply to Homo sapiens. How, then, can investigators possibly ask whether other animals think or are conscious? Focus objectively on the problems animals can or cannot solve, Hauser cautions, and leave the underlying brain mechanisms to the neuroscientists, and the speculative theories to the philosophers.
One wishes Coren and Csányi had been as circumspect. Coren has written a thorough and fascinating description of sensory information processing in dogs; the trouble is, he wants to call it thought, which just trivializes the meaning of thinking. When, late in his book, Coren does speak directly of “thinking” and “mind,” he falls into the very trap Hauser warns against. In Coren's analysis, “mind” is not a species-specific collection of tools, but rather shorthand for the set of psychological tools possessed by people, including self-awareness and the ability to reflect on one's own actions.
Coren is at his lively best when discussing the sensory capabilities of dogs, offering a clear overview of the latest research. With Coren's guidance, the reader can imagine if not the mind, then at least some approximation of the eye—and ear,
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| Children learn in three weeks what Rico has taken nine years to learn. | |
After such a detailed description of canine sensory capabilities, it is ironic that when Coren turns to the subject of dog training, the very approach he advocates is the practical application of the ideas of Skinner, who minimized the importance of understanding a specific animal's perceptual and cognitive machinery. In using this approach, Coren runs the danger of treating individual dogs as if they can all be trained alike, ignoring the exceptionally wide individual variation among dogs' abilities to learn tasks, though he does deal briefly with variations in learning from breed to breed.
Although Coren the dog lover is convinced that dogs engage in some kind of mental activity, Coren the scientist is not fooled into reading more into their abilities than the evidence seems to warrant. Toward the end of his book he fesses up: “I recognize that for the entire book I have been dodging . . . the question [of mind].” Several pages later he throws in the towel: “Although dogs may [our emphasis] have fine mental abilities,” he acknowledges, that does not mean they think “the same way that a human does.” But those admissions come only after Coren has spent a large part of his book coyly skirting the issue, hinting at what readers may want to hear rather than educating them about how to think about dog cognition in informed ways.
For all this agonizing, it may seem ironic that Coren has already anticipated the conclusion of his book by making its strongest argument early on, almost in passing. Language, he remarks, is a dividing line between the cognitive abilities of people and dogs. It's a crucial concession. After all, many dogs seem to have some capacity for understanding language, and some dogs have quite a lot. Is language the key to the mind of the dog, or is it an example of how dogs solve “just enough” of the problem of acting sentient that they convince people they are solving the complete problem?
Last summer—too late for either of these books to have taken account of the findings—Juliane Kaminski and Josep Call, both cognitive psychologists at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, reported in the journal Science on their work with a remarkable border collie named Rico. Rico, they asserted, “knew the names” for 200 objects. Perhaps even more impressively, Rico could learn the name for a novel object after the object was presented and the name was repeated just two or three times. In children, this ability to rapidly associate a word with an object is called “fast mapping,” and it is widely seen as one of the key building blocks for language acquisition.
In the same issue of Science the cognitive and linguistic psychologist Paul Bloom of Yale University provided a commentary on the work. Clearly impressed with Rico's abilities, Bloom nonetheless pointed out that, in contrast to the remarkably open–ended variety of children's vocabularies, Rico's word list was limited to the domain of the fetchable and to the specific training situation. Those restrictions make Rico's use of words quite different from that of children. Children recognize that words can be used in a variety of contexts. When they are young, they learn ten words a day, on average, and so children learn in three weeks what Rico has taken nine years to learn.
The study also presented no evidence that Rico knew anything about syntax or semantics beyond “fetch [the specific object] and give it to [x].” But therein might lie one secret of canine intelligence. Fast word mapping, even if limited to particular domains, might be all dogs need to fool the dog lover in us. It makes people believe that dogs know what people are saying, and that belief may be at the center of the social bonding that ensures their comfy lives as our pets.
In discussing the mental activities of dogs, Coren, compared with Csányi, is a model of careful and cautious analysis. In spite of Csányi's disclaimers that he is merely presenting an untested hypothesis, he repeatedly writes as if dogs not only “think,” but also have minds—in fact, a version of the same mental tool kit that people putatively possess. “My theory,” he writes, “is that humans and dogs were able to establish such tight links because . . . dogs acquired mental traits that resembled those of humans in many respects.” Csányi even goes so far as to say that the mental resemblance between dogs and people offers “a peek into the early period of our own evolution.”
That is quite a statement, and one for which Csányi offers precious little evidence. And there is more:
Through the process of domestication, we have continued to breed the descendants of animals that were attracted to us, understood our forms of communication best, and were most easily adapted to our social circumstances.
But making use of our forms of communication does not necessarily imply “understanding.” And even if one takes the quoted statement at face value, Csányi draws the conclusion that to understand human communication, the dog must have developed “mental traits that resembled those of humans in many respects.” That simply doesn't follow—dogs may be solving problems in ways completely different from the ways people do. To assume that dogs solve problems completely, and do so in completely human ways, is to close one's eyes to the special ways dogs either solve these problems or perhaps, at least, fool us, as a species, into thinking they do.
Csányi is at his anthropomorphic worst when he resorts to dog stories to reach conclusions. One section of his book is a diary of the cognitive accomplishments of his two dogs. A typical entry describes one of them as listening “with rapt attention,” looking “questioningly,” and whining “in a pleading manner.” Csányi is to be applauded for such focus on the everyday lives of dogs. And his descriptions of the many experiments done by his research group on the cognitive underpinnings of dog-human interactions are strong points of his book. But passages such as the diary entry are overloaded with anthropomorphic presuppositions about the very mental states he has set out to investigate.
Hauser's concept of mental tools may be a particularly useful way to describe the minds of animals whose world we can partly infer but never fully enter. It is obvious that, at times, both Coren and Csányi want to believe the canine mind resembles the mind of a person. Perhaps their dogs even reached into their canine mental tool kits and behaved in such a way as to convince both authors that dogs in general share many human psychological tools.
If so, that would be an amazing specialization. If dogs could write books, a good topic would be the following brain-twister: “How should dogs behave in order to get people to think that dogs are thinking like people do, so that people will behave as dogs want them to?” But even to imagine this possibility is to fall, however briefly, into the anthropomorphic trap that lies in wait for all who study dogs.
Bruce Blumberg, a research scientist at the Massachusetts Institute of Technology, is currently developing computational models of dog learning and training. Raymond Coppinger is a professor of biology specializing in canine behavior at Hampshire College in Amherst, Massachusetts. He is the co-author, with Lorna Coppinger, of Dogs: A New Understanding of Canine Origin, Behavior, and Evolution (University of Chicago Press, 2002).
| B O O K S H E L F |
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By Laurence A. Marschall |
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ONLY A VANISHINGLY SMALL FRACTION of the U.S. population lives within earshot of a moo anymore, so it's easy to forget that modern civilization and modern breeds of cattle evolved symbiotically. Cattle were domesticated perhaps as early as 10,000 years ago, and have long been a principal source of meat, milk, and power for hauling loads and tilling land. The “bovine ilk” (in Ogden Nash's inimitable phrase) was the first large creature to be genetically engineered, in the sense that it was selectively and intensively bred. In the millennia since early Mesopotamians first converted the fierce, ancestral aurochs into the contented cow, a wide variety of specialized breeds have been developed. And of all those breeds, according to M.R. Montgomery, the epitome of bovinity is the Aberdeen Angus, or Black Angus, cow.
So who is he to say? Montgomery is a writer living in Lincoln, Massachusetts, a bosky and exclusive suburb of Boston, whose only working bovine residents, to my knowledge, are confined to an Audubon Society farm (though numerous cuts of deceased specimens probably grace the Sub-Zero freezers of the town). But he has worked on a ranch in Montana, and he's a skillful and charming wordsmith; moreover, he's done his research so well that even readers without a whit of interest in cattle husbandry—vegetarians included—will find much to ruminate on in his book.
The Aberdeen Angus, as the name suggests, is a product of Scotland. At least since the Roman occupation of Britain, highland farmers have grazed cattle on their lands in the summer to sell to English markets in the south. The long, cold northern winters and a lack of plentiful forage, however, forced the Scots to sell their cattle “lean” to buyers who would fatten them up later in the more temperate English climate. Then in the early 1800s, the Highlanders discovered a readily grown and easily stored variety of yellow turnip that their cattle simply loved. Fattened cattle yielded bigger profits than lean ones, so the Scottish cattle economy and cattle-grazing industry took off. Ambitious Scottish landowners began to develop stock animals that were hardy, easy to breed and raise, and, pound-for-pound, provided the tenderest, best-tasting meat. The result was the Aberdeen Angus.
Montgomery acknowledges three of the great Scottish stockbreeders—George Macpherson-Grant, William McCombie, and Hugh Watson—as the founding fathers of the so-called Black Angus line. Those men, however, not only established a purebred line; they also managed to preserve the line by paying close attention to ancestry, establishing a formal system of cattle registry that, to this day, enables ranchers anywhere in the world to trace individual Angus cows back to members of the original herds.
Thankfully, Montgomery's book does not dwell for long on the history of the landed gentry. But he does serve up plenty of anecdotes about ranching life in the western United States, as well as welcome digressions on the economics of modern-day beef raising and the basics of bovine psychology. And there's more in this book than any noncowboy would ever want to know about artificial insemination. In the end, though, it's impossible not to share the author's enthusiasm. “Cows are also wonderful just to look upon,” he concludes. Thanks to Montgomery, they're also wonderful to read about.
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IN 1883, P.T. BARNUM'S TRAVELING CIRCUS advertised an Ethnological Congress of Strange Savages, so that white urbanites in the U.S. could gawk at such oddities as “wild” Nubians and “ferocious” Zulus. Although advertised as educational, Barnum's shows were at best a kitschy take on ethnic diversity, showcasing the skill and ingenuity of unfamiliar people, without ever letting go of the assumption that white European culture reigns supreme.
Roslyn Poignant probes the deeper subtext of these spectacles in an ambitious attempt to recreate the inner lives of two groups of Australian Aborigines. Recruited in remote villages in northeast Queensland by one of Barnum's agents, these “cannibals” looked every bit the savage to Barnum's American and European audiences. In the book's cover photograph, for instance (one of many publicity stills that Poignant has unearthed), the neatly trimmed beard, black suit, and gold watch chain of the agent, one Robert A. Cunningham, contrast starkly with the shaggy hair, loincloths, and nose ornaments of the Australians. Staring fiercely—or perhaps uncomfortably—at the camera, they brandish boomerangs and spears.
Poignant has managed to dig up a surprisingly large number of contemporary documents about these performers in newspaper files, government archives, and the business records of Barnum and his contemporaries. Several continental anthropologists, it turns out, interviewed the Aborigines during a European tour, and Cunningham himself kept a scrapbook of letters, playbills, and press clippings. The account that Poignant has assembled from all that material, as one might expect, is rather more complicated than the simple stereotype the publicity photograph seems to portray.
For one thing, Cunningham hadn't plucked his Aborigine troupe from a pristine state of nature. Some had already worked for white settlers; others for the Australian police. Their original motive for signing on to the tour is unclear, but if they were duped into thinking it was a lark, they soon made the best of the situation. Once they understood how long it might be before they returned home, they learned to speak English. They deliberately adopted the persona of stage savages—even to the point of inventing show-stopping stunts with the boomerang and elaborate yarns about life in the bush.
Offstage, it was different. In one photograph, the “savages” appear bundled up in Western-style hats and wool coats, indistinguishable, except for the color of their skins, from the white man posing with them. “We are not savages,” one of them told a reporter, “although we are natives of a wild country.”
Ultimately, though, the fate of many of the performers was a sad one. One by one, they died of infections their immune systems had never been exposed to. While the rest of the troupe moved on to the next city and the next show, the dead were buried in unmarked graves. One notable exception was Tambo, who died in 1884 and, unknown to his comrades, was embalmed and displayed as a sideshow curiosity for many years afterward. His remains were kept in the basement of a Cleveland funeral home until 1993, when they were discovered and returned to Australia for burial.
People in northern Queensland still talk about their relatives who traveled abroad as performers in the late 1800s. But though they welcomed the return of Tambo's remains, it would be premature to read Poignant's account as a sign of justice served at last. Such stage shows may have no place in our age of global consciousness, but who can say the same about the racism and xenophobia that made Barnum's spectacles so popular?
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WHO HAS NOT HEARD OF WILLIAM BEEBE (1877–1962), one of the greatest natural historians of the twentieth century? In a recent informal survey by an independent investigator (myself), every person in the physics department of a small liberal arts college recognized Beebe by name—even though none of the respondents were biologists and some of them were mere tots when he died.
Author, scientist, adventurer, radio personality (he was a frequent guest on the popular radio show Information Please in the 1940s), Beebe was equally at home in the salons of high society, the tropical jungle, or the uncharted ocean. He was a confidant of Teddy Roosevelt, a friend of A.A. Milne and Rudyard Kipling, and a dinner partner to Katharine Hepburn and Walt Disney. As a director of the Department of Tropical Research of the New York Zoological Society, he established a landmark research station in South America, where he and his colleagues conducted pioneering studies of species diversity and animal behavior. He explored the Galápagos before they became a boutique vacation site, tracked rare birds in the Himalaya, and wrote the definitive monograph on pheasants, a monumental four-volume set.
In the 1930s, at an age when most scientists are thinking of a pleasant sinecure in academic administration, Beebe entered an entirely new field of research: the study of the bottom of the sea. With little thought for comfort or safety, he and Otis Barton, the inventor of the bathysphere, sardined themselves into a five-foot-diameter steel ball, and had themselves lowered on a cable deep into the Atlantic Ocean. On one dive in 1932, radio listeners heard Beebe's voice live over NBC as he descended almost half a mile beneath the waves.
Beebe never stopped working, continuing his research at sea and in the rainforest until he was well into his eighties. He was a man of many talents, but if there was one great theme to his life, it was to carry on the scientific work of Darwin and the public advocacy of Darwinism. In two dozen books, most of them instant best sellers, he popularized the wondrous diversity of life and the interconnectedness of nature, striking themes that would be taken up in succeeding generations by scholars such as the ethologist Konrad Z. Lorenz and the biologist George B. Schaller (who currently occupies Beebe's office at the Bronx Zoo).
In spite of his high profile, however, Beebe was, according to science writer Carol Grant Gould, an intensely private person. Colleagues and students bustled around his research camps in droves, but much of the master's time was spent in solitude, lying motionless on the jungle floor as he observed the behavior of a moth or a bird, or writing a magazine article in his study. He specifically discouraged biographers, leaving his scientific papers and his voluminous daily journals to the protection of his colleague and confidant Jocelyn Crane, much to the dismay of his wife, the romance writer Elswyth Thane.
Drawing on Crane's records, made available in 1989, and a host of other sources, Gould has written an engrossing account of Beebe's professional and personal life, effectively compressing his decades of hyperactivity into a mere 400 pages. Gould is an unabashed admirer of the great naturalist, and though she tries to show some of his dark side—the occasional blue funks and some unhappy experiences in marriage—the Beebe that comes through in this book was a happy man, one of those lucky people who lived life well, inspired others to do the same, and left the world a better place.
Laurence A. Marschall, author of The Supernova Story, is the W.K.T. Sahm professor of physics at Gettysburg College in Pennsylvania, and director of Project CLEA, which produces widely used simulation software for education in astronomy.
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| Howls and Growls By Robert Anderson |
IN THE FIRST CHAPTER of his Origin of Species, Charles Darwin argued that if you wanted tangible evidence for evolution, you need look no further than the family pet. “Artificial selection” among domesticated animals, he noted, had resulted in extraordinary variations in a relatively short time, and “natural selection,” Darwin explained, would work in much the same way.
To get some sense of how much variation exists among those of the canine persuasion today, visit the Web site of the American Kennel Club (www.akc.org). The site lists entries for the 150 pure breeds recognized by the club (there are hundreds more). The Web site of the Westminster Kennel Club (www.westminsterkennelclub.org) is, of course, the best place to find information about the clubs' dog show—the premier event of its kind—which takes place in New York City on February 14–15.
If you want to explore the natural history of the domestic dog, a good place to start is the Web site of the Natural History Museum of Los Angeles County, at the online version of a recent exhibition titled “Dogs: Wolf, Myth, Hero & Friend” (www.nhm.org/exhibitions/dogs). Click first on “Evolution and Diversity,” which outlines the history and effects of both natural and artificial selection. Next click on “Form and Function,” from the vertical menu at the left, where you'll find brief accounts of the three senses that make dogs so exceptionally useful to people: vision, hearing, and smell.
For details about the impressive canine sense of smell, check out the site of the Canine Olfactory Detection Laboratory (www.vetmed.auburn.edu/ibds/doglab.htm). Trainers at the lab specialize in teaching the animals to locate explosives and illegal drugs.
Dogs are also contributing to the study of genetically transmitted disease in humans. This past summer the National Institutes of Health announced the first sequencing of a canine genome (a news summary is available at www.nhgri.nih.gov/12511476). The summary notes that, because of the long history of selective breeding, many dog genomes carry information about diseases that afflict both dogs and people. Hence canine genetic sequences will prove useful for research on, among other things, cancer and autoimmune disorders.
Genetic studies have also helped emphasize that the apparent variety among dog breeds is mainly skin deep: every domestic dog is “cousin” to the wolf. At the “Canid Genetics” page of “The Wolfdog” site (w3.fiu.edu/milesk/genetics.htm), Kim Miles, a member of the Florida Lupine Association, has summarized some of the studies, and presents them with links to the related scientific papers. Miles notes that in 1993 the American Society of Mammalogists and the Smithsonian Institution reclassified all domestic dogs as Canis lupus familiaris, a subspecies of the gray wolf.
So what about wolf evolution? On the home page of the “Natural Worlds” Web site (www.naturalworlds.org), click first on “World of the Wolf,” which will take you to the topic page. Click on “Wolf History—The Fossil Record” to find a page of images linked to information about both extinct and extant wolf species.
More on the genus Canis is available at “The Searching Wolf” (www.searchingwolf.com/ws.htm). Scroll down the home page to see an impressive list of links to sites on all things “wolf” (near the bottom, you'll even find a list of wolf sites specifically for kids). I particularly enjoyed the audio files of wolf vocalizing, which you can access by clicking on “Sounds,” in the blue menu box at the left. Launch the sound clips hyperlink, and try playing “Wolf Chorus Howling” to find out how your own domesticated wolf may react to the call of the wild.
Robert Anderson is a freelance science writer living in Los Angeles.
Copyright © Natural History Magazine, Inc., 2005