A study published on Thursday, April 16 in the Journal Science suggests that when a dog stares at its owner, it may not be because she wants more food but could actually be love (or something close).
A team led by Takefumi Kikusui, at Azabu University's school of veterinary medicine in Japan, has now found a more quantitative measure of emotion between dogs and their owners.
The scientists let owners and dogs interact. And rather than just watching each pair, the team took urine samples from the people and the dogs.
They measured Oxytocin, which is a hormone that has been very associated with trust and social bonds.
Oxytocin is the same bonding hormone thought to give parents warm fuzzies when looking at their infants.
Researchers found that when dogs stared into their owner's eyes, oxytocin levels rose in both the people and the dogs. The same was not true for wolves, who were observed with their handlers.
The team also found that when dogs were given a shot of oxytocin, they would stare into the eyes of their owners for a longer period, and that gazing, in turn, would boost the oxytocin levels in the owners. That increase points to a hormonal feedback loop between the dogs and the humans.
Taken together, the findings suggest a special bond between dogs and people — a bond that may have evolved as humans breed them.
“I'm perfectly happy saying that we can love dogs, and they can love us back, and oxytocin is probably a piece of how that happens," Evan MacLean, an evolutionary anthropologist and co-director of Canine Cognition Center at Duke University in United States says.