In each experimental group, including when a dog's owner was offering vocal praise, the dogs spent much more time with the petter than the praiser. "It's quite a shock to discover that what we say to dogs doesn't seem to be rewarding to them after all," says Wynne to The Huffington Post. "Without specific conditioning human vocalizations are as meaningless for dogs as for cats," the authors write.
"Watching my dog more carefully now, I notice that, although she certainly doesn't mind being talked to, she doesn't seek it out either," Wynne writes in an email to The Dodo. "What she actively seeks, even to the point of putting her body under my hand, is being petted."
This isn't the first time scientists have noticed the power of petting. Human contact lowers stress in shelter dogs, for example. And when humans feel a comforting touch, our heart rates and stress hormones go down, too. "When you watch dogs playing amongst themselves - or observe packs of wolves - there is a lot of physical contact, both friendly and less so," Wynne says in an email to The Dodo.