Alexandra Horowitz, a psychologist at Barnard College who studies the behavior of dogs and has written several books about them, decided to give dogs a chance at showing self-recognition on their own, smelly terms. In a recent study, she concludes that they do recognize the smell of their own urine.
While some researchers find the study intriguing, the scientist who first developed that mirror mark test doesn’t think the evidence supports her conclusion. Still, even the idea of a smell mirror is mind (nose?) boggling.
“I had always flirted with the idea in my head that there should be an olfactory mirror,” Dr. Horowitz said, acknowledging that “it could be horrifying for humans.”
Marc Bekoff, a biologist and animal behavior specialist at the University of Colorado, Boulder, broke the ice, or actually the snow, in this kind of research around 20 years ago with what has become known as the “yellow snow” study.
He found that his dog, Jethro, recognized his own scent. The evidence was that Jethro was more interested in snow marked by another dog’s urine than in snow marked by his own, even if it had been surreptitiously moved — by Dr. Bekoff.
The research had its down side. “People who saw me move the pee around thought I was weird, and someone wrote a letter to the editor of the local paper” that questioned what he was doing, he said in an email.
Dr. Horowitz took the testing a bit further, adding something like the mark on a chimp’s face: she set up dishes with different smells.
A dog’s own urine. An unfamiliar dog’s urine. A dog’s own urine along with another scent. And, in some control tests, no urine and just the unfamiliar added scent.
She tested 36 pet dogs to see how long they spent with the different scents. In many behavior tests, the time spent on a scent or a sight is taken as evidence of interest.
As she reported in Behavioral Processes, the dogs were least interested in their own urine, somewhat interested in another dog’s urine, and most interested in their own altered urine.
What that means, of course, is a matter for discussion. She says it shows that the dogs recognize their own scent, finding it less interesting unless it has been messed with.
“I don’t think it’s precisely parallel to the mirror mark test,” Dr. Horowitz said. In an odor test, you can’t “use the mirror to restore what you…