The next time you start shaking your finger and shouting "Shame on you!" because your dog chewed your favorite fuzzy slippers, just remember that no matter how guilty your dog looks, it doesn't know what your rant is about.
Behaviorists insist dogs lack shame. The guilty look — head cowered, ears back, eyes droopy — is a reaction to the tantrum you are throwing now over the damage they did hours earlier.
"Just get over it and remind yourself not to put temptation in the way next time," said Dr. Bonnie Beaver, a professor at Texas A&M University's College of Veterinary Medicine and executive director of the American College of Veterinary Behaviorists.
But scientific findings have not put a dent in the popularity of online dog shaming sites like dogshaming.com and shameyourpet.com or videos like those posted on youtube.com/crackrockcandy. In the photos and videos, dogs wear humorous written "confessions" and often are surrounded by the remnants of their misdeeds. There is no question that in some photos, they look guilty.
Dogshaming.com was the first and is among the most popular sites. Since Pascale Lemire started it in August 2012, it has received more than 58 million page views and more than 65,000 submissions. A submission has to come with a photo showing the dog's guilty look.
Lemire, who lives in Vancouver, British Columbia, also published a book called Dog Shaming, which hit the New York Times best-seller list in January.
"I don't think dogs actually feel shame," Lemire said. "I think they know how to placate us with this sad puppy-dog look that makes us think they're ashamed of what they've done."
She thinks the online dog shaming memes are all in good fun.
"People come for a laugh and camaraderie," Lemire said. "They see that their dog isn't the only one who does awful things. People don't shame their dogs out of anger, they do it out of love."
Another dog owner helped get celebrities into the trend. In late 2011, Jeremy Lakaszcyck of Boston started putting shaming videos of his lemon beagle, Maymo, on YouTube. Four months later, Ellen DeGeneres ran one of them on her show and comedian Ricky Gervais tweeted it. The popularity of the videos soared, Lakaszcyck said.
He also submitted photos to Lemire for dogshaming.com, which made Maymo even more famous.
Maymo has a naturally sad or guilty face and senses something is wrong if Lakaszcyck speaks in a stern voice. "They know when their owners are angry.
"Maymo can sit for quite a while looking sad because he's a ham. It's natural, and he knows a treat is coming. His tail usually wags through the wait. It's like he's happy on one end and sad on the other," he said.
One of the first scientific studies on the "guilty dog look" was conducted in 2009 by Alexandra Horowitz, an associate professor of psychology at Barnard College in New York City. One of her books, Inside of a Dog: What Dogs See, Smell, and Know, included the findings.
Dogs can certainly learn from bad behavior, but rewards or punishment are most effective right after the wrongdoing, Beaver said.
"Humans have a natural desire to know what an animal is thinking, and yet we are limited to reading body language and measuring physiological reactions," Beaver said.
The bottom line is: "We will never truly know because we cannot ask them."