About six million dogs are diagnosed with cancer in the United States each year. A growing field called comparative oncology studies these naturally arising tumors in pets to learn more about human cancers.
JonBee jumps up at Cesar Millan, his sharp teeth snapping repeatedly. Millan calmly yanks on the leash and pulls the wolf-like Korean Jindo away. This continues for over a minute, with Millan’s face remaining undisturbed and JonBee’s owners gasping on the other side of the living room. Finally, the dog shows a moment of weakness. Millan quickly pins him to the floor and rolls him onto his side. Millan’s calmness seems to be reflected in the dog now lying frozen in submission.
Every Friday night, troubled American dogs undergo a seemingly miraculous transformation on national television. The magician is Cesar Millan, better known as the “Dog Whisperer.” He is the current face of dog training, and he has brought “dominance theory,” an age-old training technique, back into canine conversation and practice.
To understand how to control a dog’s behavior, according to Millan, one needs to look at the hierarchy of wolf packs. Domestic dogowners must confidently carry the title of “pack leader” and assume power over their pets.
But many dog trainers and behavior experts criticize the show, advocating a gentler approach to training that replaces coercion and physical behavior corrections with food rewards and other forms of positive reinforcement. They point to new studies that have placed the two popular dog-training methods head-to-head and almost universally shown positive training to be more successful than punitive methods in reducing aggression and disobedience.
Millan may have the ratings, they argue, but purely positive trainers have the science.
No more crying wolf
Millan’s concept of dominance is based on an old understanding of the behavior of wolves. In the 1960s, researchers observed that wolves formed large packs in which certain individuals beat out others to earn “top dog” status. These were called “alphas.” Millan contends that a dog displaying aggression is trying to establish dominance and attain alpha status, much like its ancestors. He advises humans to take on this position themselves, forcefully if necessary, to keep the dog in a submissive role.
Dog trainers whose practices are grounded in these concepts, such as the late Bill Koehler and Captain Arthur Haggerty, have dominated the business for most of the past half-century. But as Dave Mech, an expert on wolf behavior at the University of Minnesota, points out, the early wolf research — much of it his own — was done on animals living in captivity.
Mech has been studying wolves for 50 years now, yet only over the past decade has he gotten a clear picture of these animals in their natural habitats. And what he’s found is far from the domineering behavior popularized by Millan. “In the wild it works just like it does in the human family,” says Mech. “They don’t have to fight to get to the top. When they mature and find a mate they are at the top.” In other words, wolves don't need to play the “alpha” game to win.
In the 1980s, around the same time that our understanding of wolves began to change, positive dog-training methods slowly emerged from the fringes and grew in popularity. A tug-of-war continues today between dog trainers practicing predominantly positive reinforcement and those using punishment-based techniques.
Nicholas Dodman, director of the Animal Behavior Clinic at Tufts University, is one of the leading proponents of positive training methods. He believes the source of most bad behavior, especially owner-directed aggression, is mistrust and recommends rebuilding a dog’s trust by “making sure that the dog understands that all good things in life come only and obviously from you.” To get those things — whether food or basic attention — the dog must learn to please you first.
But others see these techniques as little more than pampering borne out of lax and inappropriate attitudes toward pets that have recently come into vogue. “In the last ten to fifteen years it’s become, ‘don’t ever say ‘No’ to your dog; don’t ever punish dogs,’” says Babette Haggerty, who is carrying on her father’s dominance-based teaching at Haggerty’s School for Dogs in Manhattan. “I think people are coddling dogs more than ever before.”
But in 2004, “The Dog Whisperer” — Millan's doggy psych 101 — premiered on the National Geographic Channel, and the momentum mounting in the positive direction was stymied. “In America, we [had begun] using human psychology on dogs,” Millan says in an email. “What was needed was for humans to learn dog psychology.”
Perils of punishment
Many veterinary behaviorists believe punishment-based techniques, like those seen on the show, could come back to bite dog owners. The National Geographic Channel even posts a warning on the screen during each episode: “Do not attempt these techniques yourself without consulting a professional.”
According to a paper in the May 2009 issue of the Journal of Veterinary Behavior: Clinical Applications and Research, attempts to assert dominance over a dog can increase a dog’s aggression. Researchers from the University of Bristol in the United Kingdom studied dogs in a shelter for six months, while also reanalyzing data from previous studies of feral dogs. Their findings support those of the Mech at the University of Minnesota: dogs don’t fight to get to the top of a “pack.” Rather, violence appears to be copycat behavior — something borne of nurture, not nature.
In another recent study, around 25 percent of owners using confrontational training techniques reported aggressive responses from their dogs. “The source of dog aggression has nothing to do with social hierarchy, but it does, in fact, have to do with fear,” says Meghan Herron, a veterinarian at The Ohio State University and lead author of the study published in the January 2009 issue of Applied Animal Behavior Science. “These dogs are acting aggressively as a response to fear.”
Dogs react physiologically to stress and fear in the same way people do, with hormones. Two 2008 studies out of Hungary and Japan showed, respectively, that concentrations of the stress hormone cortisol increased in dogs that were strictly disciplined and that levels were linked to elevation of aggressive behavior. What’s more, an Irish study found that physically or verbally reprimanding a dog with a history of biting people was one of the significant predictors of a subsequent bite. The results were published in April 2008 in Applied Animal Behavior Science.
“[All these studies] confirm what many of us have said for a long time,” says Pat Miller, owner of Peaceable Paws dog and puppy training in Hagerstown, Maryland. “If you use aggression in training your dog, you’re likely to elicit aggression back.”
Paybacks of positive reinforcement
Before practicing professionally as a dog trainer, Jolanta Benal of Brooklyn, New York, learned the difference between positive and punitive methods personally.
Her dog, Mugsy, had an attraction to men in uniform. Whether they were wearing UPS brown or U.S. Postal Service blue, Benal's bulldog would lunge at them on the street. So she hired a highly recommended dog trainer to try to correct this behavior.
“He would set Mugsy up to do offending behavior, and then throw a can full of pennies at the dog,” she says. “It was a traditional old school technique. And it worked to suppress the problem behavior — at least in the moment.” Mugsy’s unhealthy obsession with the postal workers, however, did not go away. Even if he didn’t always jump at the UPS guy on a walk-by, says Benal, he wasn’t happy to see him either.
Benal then traded in for a new trainer that brought chicken instead of coins. As the man in uniform approached, Benal was now instructed to distract Mugsy by giving him the treat. And it worked. After several times, the dog would look to her in expectation, rather than towards the uniform-clad men in alarm. “For the last year of his life, he was an angel,” says Benal. “It was amazing the changes it brought.”
Millan argues that using food to coax dogs may be impractical: “It can result in an addiction to treats or an overweight dog,” he says in an email. However, Dodman of Tufts University explains that trainers only give food at the beginning of training. After a period of time, owners should reward intermittently, reinforcing the response. “If every time you played the lottery you won money, then the excitement wouldn’t be there anymore,” says Dodman. “The thrill for the dog is ‘Will I get a treat this time?’” Back-aches from stooping low to feed a dog, or the added cost of extra chicken or doggy treats, he believes, are far less dreadful than the anxiety and altered relationships caused by the punitive alternative.
Dodman has some data to back him up. In February 2004, a paper in Animal Welfare by Elly Hiby and colleagues at the University of Bristol compared the relative effectiveness of the positive and punitive methods for the first time. The dogs became more obedient the more they were trained using rewards. When they were punished, on the other hand, the only significant change was a corresponding rise in the number of bad behaviors.
A series of more recent papers also support Dodman’s theory and Hiby’s results. A study published in the October 2008 issue of Journal of Veterinary Behavior found that positive reinforcement led to the lowest average scores for fear and attention-seeking behaviors, while aggression scores were higher in dogs of owners who used punishment. Another 2008 study, this one published in Applied Animal Behavior Science, found that positive training methods resulted in better performances than punishment for Belgian military dog handlers.
Bridging the differences in dogma
It’s hard to argue that the slow, patient techniques used in positive reinforcement would elicit the same dramatic moments seen on Cesar Millan’s show. “There’s a big difference between looking at behavior as a ‘Stop that’ versus a ‘Here’s what I want,’” says Bruce Blumberg, a professor of dog psychology at the Harvard Extension School. “Positive reinforcement is a different mindset. And it’s one that doesn’t work quite as well on TV.”
Dodman is one of many people who have asked the National Geographic Channel to discontinue “The Dog Whisperer,” consistently one of the highest-rated shows on the network. The American Humane Association issued a press statement in 2006 asking for a cancellation because of what they suggested were abusive techniques used by Millan. More recently, the American Veterinary Society of Animal Behavior issued a position statement in which it expresses concern “with the recent reemergence of dominance theory and forcing dogs and other animals into submission as a means of preventing and correcting behaviors.”
Millan defends his methods, asserting they “use the minimum force necessary to prevent or correct a problem.” According to the dog rehabilitator, he can “redirect the behavior of most of my pack with just my body language, eye contact and energy.” He points to the “thousands upon thousands of letters” he receives from viewers touting “miracles” of restored relationships and saved dogs. “All I want is what is best for the animal,” Millan says.
Despite the controversy, there is a lot that everyone agrees on. Both sides of the training spectrum teach that a lack of discipline or structure is not conducive to a well-behaved dog. “Dogs need direction and boundaries, just like human relationships,” says Haggerty, the trainer from the School for Dogs in Manhattan, which uses dominance theory. “If dogs don’t know what the boundaries are, they will wreak havoc.”
How a dog owner projects those boundaries is also important. “You have to be calm, you have to be clear, you have to be consistent, and you have to make sure you meet your pet’s needs for other things: exercise, play, social interaction,” says Herron of The Ohio State University.
So what does an owner do when a calm and structured environment still breeds a misfit pup like JonBee? Should it be the leash and hand that redirects the dog, or poultry and patience? Current science favors the chicken flavor. But whichever strategy you choose, everyone agrees that the timing must be precise. It is very difficult for a dog to make an appropriate association and learn from the reprimand or reward otherwise.
Of course, if you take Blumberg’s Harvard class, he'll tell you, “If your timing is lousy using positive reinforcement, the worst thing that happens is you get a fat dog.”
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This article is provided by Scienceline, a project of New York University's Science, Health and Environmental Reporting Program.