Potent as a marketing trend, humanization has long been scorned as scientific practice by researchers working in the behaviorist tradition of B. F. Skinner. In “Inside the Animal Mind,” George Page summarizes the reasons: “Since we cannot get inside the animal’s mind . . . and since the animal cannot report what’s going on  not in a ‘language’ we can readily understand  all we have left are guesses and speculation fatally tainted by anthropomorphism.” Strict behaviorists focus instead on observable stimulus-response conditioning: for example, a puppy learning to sit to receive a treat. Actions that cannot be explained this way are usually attributed to blind instinct. As such, hard-core Skinnerian philosophy amounts to a perversion of cogito ergo sum: I can’t prove that animals think, therefore they don’t. In dealing with problem pets, veterinarians with a behaviorist bent don’t concern themselves so much with what might be happening inside the brain of the animal or try to correct neurochemical imbalances with drugs. Instead, a compulsive or anxious animal is seen as one that just needs to be better-trained.

Image Credit... Photo Illustration by Zachary Scott for The New York Times

The debate about animal minds is at least as old as Aristotle, who posited that men alone possess reason. The 17th-century French philosopher Nicolas Malebranche wrote that animals “desire nothing, fear nothing, know nothing,” while Voltaire asked, “Answer me, mechanist, has Nature arranged all the springs of feeling in this animal to the end that he might not feel?” Darwin’s view was, Of course not. In “The Descent of Man” he wrote, “We have seen that the senses and intuitions, the various emotions and faculties . . . of which man boasts, may be found in an incipient, or even sometimes in a well-developed condition, in the lower animals.” The staggering assertion of Darwin’s theory is that evolutionary continuity applies not just to bodies but to brains. “The difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind,” he wrote.

For much of the 20th century scientists willfully dismissed this line of thinking, which has been rekindled only in the past three decades with the rise of a field known as cognitive ethology. The guiding belief is that while it is scientifically baseless to assume that animals think and feel just as we do, it is equally foolhardy to assume that they don’t think and feel at all. In laboratory experiments and field observations, practitioners have presented evidence of analogical reasoning by apes, counting by rats and the capacity of pigeons to distinguish the paintings of Picasso from those of Monet. Researchers have demonstrated that animals can grasp basic abstractions like “same” and “different” and use mental flexibility to solve novel problems in the laboratory for which hard-wired instinct couldn’t have prepared them. It is impressive but perhaps unsurprising that a parrot was taught to categorize colors or that dolphins learned the syntactic distinction between “take the surfboard to the Frisbee” and “take the Frisbee to the surfboard”  we already tend to think of these animals as being smart. More eye-opening are glimmers of cognition from way down the phylogenetic chain. Research has shown that bumblebees can remember which flowers they have already visited and that two-inch-long cockroaches from Madagascar can tell the difference between a familiar person and a stranger. (If the bug hisses loudly at you, it’s time to introduce yourself.)

Cognitive ethologists have had more difficulty gathering evidence for animal emotion. To any pet owner who has stroked a purring cat or watched a dog cavort when his chow hits the bowl, it seems intuitively obvious that animals experience feelings. But intuition isn’t hard science  it’s just more humanization. Enter behavioral pharmacology, which has provided a tantalizing new window into the animal mind. Dr. Nicholas Dodman, who pioneered the field and founded the Tufts University Animal Behavior Clinic, says that skeptics of the premise that animals have emotional states used to ask him how he could say that a pacing, hyperventilating dog was actually feeling anxious. “Well, how about this?” Dodman would reply. “We’ll give him an antianxiety drug and see what happens.”

THE GROUNDS OF THE CUMMINGS School of Veterinary Medicine at Tufts sprawl over 640 acres of rolling greenery in central Massachusetts. When I arrived to visit in March, one of the first things Dodman told me was that the campus used to be the site of a state mental hospital. Like other facilities, it had been shuttered in the 1960s following the revolutionary discovery of drugs that treated schizophrenia and other disorders so effectively that many patients no longer required institutionalization. “Ironically, this paved the way for our school, our behavior program, and novel pharmacological treatments for animal behavior problems,” Dodman said. Or, as he later said, “we traded one group of inmates for another.”

Dodman, an Englishman, began his career in the early 1970s as a roving country vet in the tradition of James Herriot; he went on to write a popular series of advice books for pet owners, the latest of which is “The Well-Adjusted Dog.” In 1981 he moved to the United States to become a professor of anesthesia at Cummings. Drugs interested him greatly but comatose patients, increasingly, did not, and he began to wonder: Could medications transform veterinary behavioral medicine just as radically as they had human psychiatric care? He says he quickly realized that the field was “completely wide open, like virgin snow.” At a veterinary conference in the late 1980s, he presented his vision of the psychoactive frontier and “saw jaws drop around the room. It was like, ‘Who is this strange masked man?’ ” Three decades later, “it’s almost mainstream for behaviorists to know something about pharmacology,” Dodman says.