GabyMost people today prefer friendly, calm pets that fit a more sedentary lifestyle. Just a few decades ago, dogs were seen as working animals tasked with hunting, herding livestock, and guarding homes. Today, the primary focus for most pet owners is companionship. Researchers at Linköping University in Sweden found this cultural shift is linked to oxytocin, the hormone behind social bonding — a trait especially visible in many service dog breeds. The hormone drives dogs to seek closer connections with their owners, the Daily Mail reports. The Swedish team argues that as humans domesticated wolves into companions, dogs became more sensitive to oxytocin.
What did the researchers find? During the study, the team examined how dogs develop their ability to work alongside humans, especially their willingness to ask for help when faced with a difficult problem. The scientists hypothesized that oxytocin plays a role, since the hormone influences social relationships in humans. Oxytocin’s effect depends on how strongly it binds to its receptor inside cells. Previous studies show that genetic variations near the oxytocin receptor gene affect dogs’ willingness to communicate. In other words, dogs’ social skills are partly encoded in genes that control their sensitivity to oxytocin.
During the experiment, the researchers observed 60 golden retrievers trying to lift the lid off a jar containing treats. As you might guess, the scientists made the jar impossible to open. They also collected DNA samples from the dogs’ noses to determine which oxytocin receptor variant each dog carried. The dogs did the behavioral test twice: once after receiving a nasal oxytocin spray and once after getting a neutral saline solution. The team timed how long each dog tried to open the jar on its own before asking the owner for help. Dogs with a specific receptor variant showed a stronger response to the oxytocin spray and were prompted to ask for help more often than after the saline. These results shed light on how domestication has changed genes that influence dogs’ social skills.
What else do scientists say about the third wave of dog domestication? The study suggests dogs are entering a third wave of domestication. This idea is supported by American dog behavior specialists Brian Hare and Vanessa Woods. As dogs shifted from working animals to companions, their behavior — and possibly their biology — changed, the experts say. Hare and Woods point out that more dogs now live in densely populated areas, increasing contact with unfamiliar dogs and people. At the same time, some traits that helped dogs survive with our ancestors are now maladaptive. “More energetic, excitable, fearful, or anxious dogs are more likely to end up in shelters, where they struggle to find new homes,” the experts say.
The first wave of dog domestication occurred during the Upper Paleolithic (about 40,000 to 14,000 years ago). It began when humans formed hunter-gatherer communities and often left food scraps near their settlements. Woods and Hare say wolves that took advantage of this food source gained a survival advantage, and over time attraction to humans displaced fear and aggression.
The second wave began after the Industrial Revolution, when the burgeoning middle class adopted dogs as a sign of taste and wealth. Breeders started selecting dogs for specific physical traits, creating many modern breeds. Now dogs are entering a third wave focused on adapting temperaments to the modern world. Woods and Hare say humans should actively support this process.
