Humans use eye contact all the time, from bonding with our babies to sharing an awkward glance with someone during an embarrassing situation. Eye contact isn’t just for humans though – dogs use it too. Man’s best friend has learned to use eye contact to connect and communicate with humans extraordinarily well. Researchers at Yale’s Canine Cognition Center (CCC) set out to learn more about how this behavior developed over the course of the domestication process by comparing dogs, wolves, and dingoes.
We can learn a lot about ourselves by observing the behavior of animals that spend a lot of time around us. “Across domestication, dogs have come to learn from humans in much the same way as human children learn from adults, so dogs and dingoes offer us the unique opportunity to examine how these human-like abilities may have evolved,” said Yale graduate student Angie Johnston. Johnston works in the CCC alongside Laurie Santos, Ph.D., who directs the center, observing canine behavior to answer these types of questions.
Back in 2015, a Japanese group found that both dogs and humans experience a rush of oxytocin – a hormone associated with bonding and warm fuzzy feelings – when they make eye contact with each other. In contrast, wolves that underwent the same experiments rarely made eye contact with their handlers and didn’t show similar oxytocin spikes even when their eyes did meet.
For dogs, eye contact has practical uses that extend beyond warm fuzzy feelings. When dogs were given a difficult puzzle to solve, they looked at their owners more frequently, seeking help or looking for solutions based on where the human’s gaze is directed. On the other hand, labs that compared dogs’ problem-solving behavior to wolves’ found that the wolves tackled the puzzle independently and mostly ignored the humans.
The CCC added nuance to these previous studies by collecting observations from Australian dingoes that underwent the same experiments. Wolves are considered the standard undomesticated ancestor; in contrast, dingoes associate frequently with humans but have never been selectively bred like dogs. The last shared ancestor between dingoes and modern dogs existed roughly 5000 years ago. As a result, dingoes represent an intermediate step in canine domestication.
By studying dingoes, researchers can notice subtle effects of complete domestication that may be overlooked when comparing dogs to wolves. “If we see differences in dogs and dingoes, it’s coming from a really tiny window of domestication,” said Santos. The dingoes in this recent study made eye contact with humans less often than dogs, but more often than wolves, indicating that some motivation to make eye contact developed even before the tiny window separating dingoes and dogs.
“Our study in particular suggests that eye contact between humans and canids may have evolved relatively early in the domestication process, before humans began actively breeding dogs,” said Johnston. “This is significant because it suggests that one of the most foundational aspects of canine social cognition was already being shaped very early in domestication.”
The results led researchers to hypothesize that the bond between humans and dogs may have developed in two stages. Early efforts at domestication might have favored dogs that showed some tendency to make eye contact, since that would have elicited some of the same warm fuzzy feelings as parent-child eye contact. Once some bond was established, humans probably started treating dogs as social partners, which would have prompted dogs to start learning eye contact as a form of communication.
Looking ahead, Johnston expresses enthusiasm about how she expects this research to move forward. She’s especially interested in diving deeper into social cognition and the communicative aspects of eye contact. She points out that understanding domestication and canine cognition not only helps unravel history but can also have practical implications for our day-to-day interactions with the canines in our lives. “Understanding more about how the bond between our two species develops may help promote healthy relationships between people and their pet dogs, therapy dogs, service dogs, and emotional support dogs,” she said.
 Email correspondence with Angie Johnston on 1/29/18
 Interview with Laurie Santos on 9/7/17