For hints on humans, scientists study dogs' thinking

CAMBRIDGE - Studying a species known to chase its own tail may seem an unlikely way to better understand the human mind. But scientists at Harvard University's new Canine Cognition Lab hope to gain insight into more than the psychology of dogs from visiting pet pooches - including an alert German shepherd named Celia and a rottweiler called Taylor who loves to eat chicken.

Researchers have long looked at other species' reasoning abilities and behavior to discern what makes humans distinct. The Harvard team is now turning to dogs because on certain tasks, such as understanding pointing, dogs easily outperform animals much more closely related to humans, even chimpanzees.

Scientists are also drawn to dogs because of their unique history growing up in the same environment as people, and they hope to learn whether domestication has led to dogs that think and act more like their masters - or whether we just think they have human traits.

"Here's this species we live with. Everyone has their views about how smart they are. No doubt we are overinterpreting - and in some cases underinterpreting," said Marc Hauser, a Harvard professor who has long studied cognition in cottontop tamarin monkeysand who heads the new lab. "To what extent is an animal that's really been bred to be with humans capable of some of the same psychological mechanisms?"

Can dogs understand such abstract concepts as "same," for example? Or, can dogs be patient? To answer such canine conundrums, Hauser is recruiting both purebreds and mutts and running them through simple tests. In return, they earn tasty treats.

Dogs are interesting in their own right - for animals that are an intimate part of millions of families, they are still surprisingly mysterious to us. Researchers at Harvard and more established dog labs say their work could have many practical results, including new therapies for misbehaving dogs and more stimulating ways to play with your pet.

At an animal cognition conference last month, there were two sessions devoted solely to dogs, a scenario that would have been unthinkable just a few years ago, according to Clive Wynne, a psychology professor at the University of Florida who also studies the pets. While Ivan Pavlov famously studied dog behavior in the late 19th century, dogs have mostly been neglected by scientists studying animal thought.

"Psychologists have been ignoring animals that were sleeping quietly at their feet while they were doing work on rats and pigeons," Wynne said. "Darwin wrote about his dog. . . . We couldn't bring ourselves to take them seriously."

In Hauser's lab, researchers are starting their work by testing whether dogs can understand simple communicative gestures, such as pointing to a bucket that has food in it, as well as more complicated tasks.

During a recent videotaped session, assistant lab manager Natalie Shelton stared a fluffy white Samoyed straight in the eye, dropping a dog treat into a bucket marked with a triangle on the outside. Then she hid the bucket behind a screen and revealed two other buckets: one marked with a triangle and the other with a circle. (Both held treats to ensure the dog couldn't cheat by using its sense of smell.)

Shelton bowed her head and the dog was released. The Samoyed headed straight for the bucket with the circle, suggesting it didn't grasp the concept of "same."
In another trial, researchers tested whether dogs can use pictures as signs to figure out which bucket contains food. They presented Celia, the German shepherd, with a choice between a bucket marked with a picture of steak and one marked with a pair of pliers. Celia picked the steak.

Katie Levesque, Celia's owner, said she tries to give her dog challenging tasks at home but was surprised that her dog picked pictures of food three times, also choosing a hot dog over a hammer, and three biscuits over one.

"I was kind of laughing," said Levesque, who sat in a corner of the room with Celia at her feet during the experiment. Owners can also watch their dogs from behind a one-way mirror. Only about 20 dogs have been tested, so it's too early to draw conclusions about dogs' comprehension of pictures.

As Hauser's lab recruits more dogs, he hopes to ask more sophisticated questions and gauge the limits of dog reasoning.

Some of the most interesting results could come from studies that test the qualities people ascribe to their pets: loyalty, for example, or guilt. Alexandra Horowitz, who teaches psychology and animal behavior at Barnard College in New York, has probed the guilty look that dogs give, flattening their ears back and ducking their heads.

In work recently accepted for publication in the journal Behavioural Processes, Horowitz had owners show their dog a desirable treat and then tell the dog not to eat it. They would leave the room and the experimenter would either give the dog the treat or take it away. When the owners returned, some dogs were scolded, even if they had not disobeyed.

Researchers found that dogs looked most guilty when they were scolded, especially when they did not eat the treat.That suggests dogs are responding to a social cue. Even though we may associate a certain look with the way we feel, teasing out dogs' actual thoughts and feelings requires careful experimentation.

Peter Mendelsohn of Sedgwick, Maine, said he brought Taylor to the lab because he was attracted to the idea of using science to understand animal behavior.As much as he tries not to anthropomorphize, he said, he often finds himself saying such phrases as "my dog thought . . ." or "my dog believed."

"It's just nuts," Mendelsohn said. "If you have an animal and it's more than that, it's truly a member of your family, you see things every day that you don't have the ability to explain or describe, but you know how important it is to you."

The Canine Cognition Lab is recruiting dogs. For more information, visit Carolyn Y. Johnson can be reached at