Study: Dogs make 'puppy eyes' on purpose to bond with humans

Good news dog lovers: your pooch really does adore you!

Turns out that bond you feel is mutual thanks to the hormone oxytocin. RT.com reports: 

We know it as the love hormone: it spikes when we hug, kiss and make love. It also exists between a mother and infant, as they gaze into each others' eyes. But oxytocin is more than that. The hormone is one of the most important evolutionary bonding mechanisms known to man. Without it, affection, trust and altruism, as we know them, would never have been possible.

Oxytocin levels spike in both dogs and humans when they are given the 'puppy eyes' according to the study from Azabu University's School of Veterinary Medicine in Sagamihara, Japan.  Professors found that this is the first time the mechanism has been observed between species. Meaning dogs look into our eyes with love just like we do theirs.

Humans have long had this bond. For example, when a mother looks into the eyes of her infant. Both release oxytocin and reinforce it, feeding off of the feeling. In dogs, if pups are separated from their mother, they make a series of ultrasonic noises that causes moms to release more oxytocin and start nurturing them. The pups release more of the hormone as well, resulting in attachment behavior.

Professor Miho Kikusui and his colleagues invited 30 of their friends with pets to test the theory. The first step was to have each owner and their pet interact separately with each other in a room for 30 minutes. Urine samples were taken from both owner and dog to scan for changes in oxytocin levels. Researchers found that the more a dog gazes into a human's eyes, the more pleasure and child-like feelings of love it has. The spike was also found in their human BFF's. 

"It's an incredible finding that suggests that dogs have hijacked the human bonding system," Brian Hare, an expert on canine cognition at Duke University, North Carolina, who was not involved in the research, was quoted as saying in a Science article. 

So now you know when your favorite furry friend looks into your eyes adoringly, they really do love you as much as you love them.