Scientists desperately want to understand how human social behavior works—like how we discern nonverbal cues—and why it sometimes breaks down—like when we become aggressive in inappropriate situations. Yet for something that happens all the time out in the real world, it’s almost impossible to study in a lab setting, because real-world social behavior is a complex mess of many levels of interaction occurring simultaneously. It’s difficult to isolate just one type of behavior and attribute it to one cause. This is where humanity’s best friend could lend a helping paw in advancing social sciences.
A study published on Thursday (Sept. 29) in Scientific Reports suggests that dogs and humans share some of the genes associated with social behavior. Scientists think that this discovery could help them gain a better understanding of certain social disorders in humans by studying canine models.
Per Jensen, an animal behavioral scientist and lead author of the paper, explained that these genes likely originated through the domestication process of dogs, which happened in two different instances between 10 and 30 thousand years ago. “When humans tamed wolves, and turned them into dogs of various breeds, the ones with the highest degree of sociality were kept for further breeding,” he wrote in an email. With evolution, traits that are favored—either because they promote some kind of advantage to survival or, in this case because we bred them that way—appear more often because animals without them never get the chance to pass them onto offspring. “This has placed a strong selection pressure on the gene variants we have discovered.”
In this particular study, Jensen and his colleagues presented 430 different beagles each with three Plexiglas coverings hiding a treat. In two of the cases, the lid was loose and easy to move, but in the third, it was fixed in place. The researchers recorded whether or not the dogs looked to a woman (unfamiliar to the animals) standing nearby for help with the immovable lid as an indication of how social the dogs were.
Researchers then sequenced the genomes of 190 of the beagles, half of which seemed to want human help and half of which didn’t. In doing so, they found two genetic markers that seemed to be associated with dogs seeking out attention from humans, which included variations on four nearby genes that have been associated with human behavioral differences, including autism, schizophrenia, and aggression in patients with attention deficit hyperactivity disorder (ADHD). Taken together, these results imply that dogs and humans have at least some of the same genetic basis for social tendencies.
Genes can’t ever tell us the full story of why any human or animal behaves the way they do. Jensen estimates the genes they identified in dogs likely account for about “30% of the variation in sociality.” Genes only give us a basic outline of different traits, including the tendency to behave one way or another. But so many other factors play a part in shaping sociability in dogs, including how they’ve interacted with humans in the past and epigenetics, or the differences in how the same genes are expressed in different individuals.
Jensen and his team are currently studying the ways different genes associated with social behavior are shared among different breeds of dogs. Because dogs have been used in the past as models for understanding certain human behavioral disorders, like obsessive-compulsive disorder (paywall), they think their genetic work could lead to better canine models for understanding other human social disorders, like autism or ADHD.