A rush of hormone that helps people bond could explain why humans and dogs have been best friends for thousands of years, say researchers in Japan.
The scientists found that dog owners experienced a surge of oxytocin when their pets gazed into their eyes, a dramatic effect that was mirrored in the animals themselves.
The same hormone has been shown to spike in mothers’ brains when they look into their children’s eyes. The physiological response drives maternal caring and strengthens the bond between mothers and their babies.
The latest finding suggests that dogs have tapped into this ancient biological mechanism, and through it reinforced the ties that have existed between humans and dogs since the animals were first domesticated thousands of years ago. “This might be why the human-dog relationship seems to work so well,” Takefumi Kikusui at Azabu University said.
To investigate how dogs and humans formed their special relationship, Kikusui’s team ran a series of experiments. They began by watching 30 owners play with their dogs for half an hour. The breeds included golden retrievers, poodles, a Jack Russell terrier, a German Shepherd dog, and several miniature schnauzers. The group was an even split of males and females.
Urine tests before and after the session revealed that oxytocin levels spiked in people whose dogs stared at them the most. But their dogs experienced a similar effect.
They went on to perform a further experiment. This time, the researchers sprayed either salt solution or a dose of oxytocin up the dogs’ noses before watching them in a room with their owners. Dogs that had received the hormone boost stared for longer at their owners.