A new study on the brain chemistry of canines is confirming what pet-owners have long suspected -- dogs really are capable of loving us, and the warm, fuzzy feeling is probably mutual.
Love is a complex and difficult to define emotion, but from a biological standpoint researchers have long known that feelings of closeness and intimacy are related to the release oxytocin, known as the "neurochemical of love".
Measuring an increase in oxytocin in the bloodstream can give scientists sense of how strong a feeling love an interaction elicits. For example, a shaking hands with a stranger might raise oxytocin levels 5 to 10 percent, or a slight sense of closeness. Receiving a hug from ones child, on the other hand, could boost that up to 100 percent.
Researcher Paul Zak from Claremont Graduate University recently set out to discover how oxytocin is triggered among non-humans -- in other words, to find out if they might have loving feelings, too, for creatures unlike themselves.
In picking his test subjects, Zak couldn't have found a more adorable pair. He travelled to an animal refuge in Arkansas where a domestic mixed-breed terrier and a goat had apparently become friends, frequently engaging in play. They seemed to enjoy one another's company, but Zak intended to find out just how strong their feeling might be.
After allowing the two animals chase, jump, and roughhouse for 15 minutes, Zak took samples from both animals and discovered they were indeed fond of each other -- though one a bit more than the other.
"We found that the dog had a 48 percent increase in oxytocin. This shows that the dog was quite attached to the goat. The moderate change in oxytocin suggests the dog viewed the goat as a ‘friend'," writes Zak, in The Atlantic.
"More striking was the goat's reaction to the dog: It had a 210 percent increase in oxytocin. At that level of increase, within the framework of oxytocin as the ‘love hormone,' we essentially found that the goat might have been in love with the dog."
Zak says levels like the goats have only been measured in humans "when someone sees their loved one, is romantically attracted to someone, or is shown an enormous kindness."
While the meaning of love may be more the purview of poets and philosophers, in terms of chemical response within the brain, animals and humans might just feel the same way about those they are closest with.
"That animals of different species induce oxytocin release in each other suggests that they, like us, may be capable of love," Zak says. "It is quite possible that Fido and Boots may feel the same way about you as you do about them. You can even call it love."