We have a lot of scientifically dodgy beliefs when it comes to our dogs.
The idea of needing to show a dog you’re the “alpha” is based on flawed science; they don’t actually see in black and white; and the concept of “dog years” – where one human year equates to seven years in a dog’s life – is a myth.
But a new brain-scanning study has revealed new insights into something most dog lovers know to be true: our canine companions are excellent at reading and responding to human emotion.
They can tell when we’re happy or sad, and are better at distinguishing between negative emotions such as fear, sadness and anger than we thought. Dogs can read us even better than chimpanzees, our closest evolutionary relatives, the authors claim.
In particular, dog brains light up at happy human faces; even smiles from strangers activate the same region of a dog’s brain that responds to rewards such as toys and treats.
Here’s how researchers pinpointed what’s going on inside the brains of our canine companions, and why science says we must smile at every dog we meet (just in case you weren’t doing that already).
What a human smile does to a dog’s brain
The study was undertaken in Hungary and Mexico. Researchers Dr Raul Hernandez-Perez and Dr Laura Cuaya scouted parks for dogs who seemed calm and well trained, and approached their owners to recruit them for the study.
They gathered a group of 14 dogs, made up of border collies (including the researchers’ own dogs, Odin and Kun-kun), golden retrievers, a labrador and a mutt.
Then came the hard part. Even humans find MRIs freaky. How would dogs fare in the clanky, clamorous cylinders, much less stay still enough for the test? Moving just three millimetres during a scan would render the data useless.
Over 20 training sessions, the researchers painstakingly trained the dogs to lie still in the chamber, in a sphinx position with their jaws on a chin rest, rewarding them with treats and play for lying still.
They gradually built from five seconds of stillness to the full three minutes, and introduced special earmuffs to protect the dogs’ hearing.
Training complete, the dogs were scanned while researchers showed them images of human faces that were happy, sad, angry, fearful or neutral.
Happy human faces triggered activity in the temporal cortex, an area of the brain that recognises faces and processes emotional cues, and the caudate nucleus, which handles rewards and motivation.
“The activity in the caudate nucleus is particularly interesting,” Cuaya, from the University of Vienna, said on the release of the research. “It suggests that happy human faces may have emotional significance for dogs.”
‘We should smile at the dogs – even at random dogs in the street.’
Laura Cuaya, University of Vienna
Fear and sadness, on the other hand, activated a different region of the brain called the right rostral suprasylvian gyrus (which processes visual and other sensory information), while anger lit up different sections called the right ectosylvian gyrus and the left splenial gyrus.
Jargon aside, the results show dogs react uniquely to happiness and provide the first evidence dogs can tell the difference between some negative facial expressions (although they didn’t seem to distinguish well between sad and angry faces).
Taken together with other studies, one of the main takeaways is that dogs interpret human happiness – even the smiles of strangers – as a reward.
“We can reward our dogs with treats but also reward them with happiness,” Cuaya told the BBC. “So we should smile at the dogs – even at random dogs in the street.”
One key tip to give your dog a good life
Animal welfare scientist and dog expert Dr Mia Cobb, who wasn’t involved in the study published in iScience, says the sample size is small, but the study offers valuable proof-of-concept findings that could be tested on other breeds.
She says the dogs in the study responded stronger to fear and anger over sadness.
“If we’re feeling scared or angry it is really valuable for a dog to pay attention to that,” Cobb, from the University of Melbourne, says. If a person is scared, it could signal to a dog there’s danger nearby, while an angry person might pose a direct threat to a dog.
“If we’re feeling sad it’s less relevant for the dog because it’s probably not going to threaten their safety.”
While the study tested dogs’ reactions to still images, in reality they respond to a range of cues, including our tone of voice, body language and, crucially, smell.
“There’s been emerging evidence over the last couple of years that really shows dogs are very responsive to things like the odour of fear or odour of anxiety,” Cobb says.
On that point, one of the best things we can do for our dogs’ welfare (besides smiling at them) is slowing down on walks and letting them sniff. A good whiff of a funky patch of grass is the dog equivalent of taking in a stunning mountain view, Cobb says.
“They really live in a smell-based world, so letting them stop and sniff that tree trunk or wooden post that everyone else has peed on today is actually really important to them living a good life.”
Dr Tiffani Howell, a senior research fellow at La Trobe University, says the results should prompt us to better understand our pets. “Dogs are great at reading us but we’re not great at really reading them,” she says.
Take the stereotypical, slinking, “guilty” look you might get after a dog tears up a toilet roll or destroys a shoe. Research shows the dogs are not really feeling guilty – it’s more likely they just know their owner is angry, and act submissive to avoid punishment.
A few studies do, however, suggest our pups can experience jealousy when we pat or play with other dogs.
In another just-published study on dog brains, researchers analysed ancient dog breeds (the Samoyed, the New Guinea singing dog, and the African and Korean village dog) and compared them with modern breeds (border collies, labradors and German shepherds).
Thousands of years of artificial selection has rewired the communication-related networks in the brains of modern dogs, boosting their capacity to process words and vocal cues from humans, the researchers reported.
“We’ve lived very closely together for a really long time, and nowadays, dogs are reliant on humans for pretty much everything,” Howell, who wasn’t involved in either study, says. “It makes total sense that they would learn to read us very well.”
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