New Study Shows Dogs Cry Emotional Tears When Reunited With Owners

You know your dog loves you – there’s no doubt about it – but did you know that your pooch can get all teary-eyed when they are overwhelmed with emotions? For the longest time, it was believed that humans are the only ones that produce tears when emotional, but a new study done in Japan shows that man's best friend adopted the same trait, too. 

A team of Japanese researchers published their findings in the Current Biology journal, and the results are quite curious. They measured tear levels before and after the reunion of dogs with their owners and noted a significant increase in tear volume after the dogs have been reunited with their humans – and all because of oxytocin. Seeing their owners again after a period of separation produced oxytocin, or “love hormone”, in the dog’s bodies, and that stimulated the tearful response. In turn, the eye contact of owners with their dogs increases oxytocin levels in humans, which strengthens their bond on both sides. The study involved 18 dogs, and the results were consistent across the board – but that’s not all they wanted to learn.

After concluding this part of the research, scientists rounded up 74 participants to test how people react to dogs with moist eyes, and if the perception of teary-eyed dogs elicits an emotional response. They were shown 10 photos of dogs, some with moist eyes and others without, and were asked to rate how much they were inclined to care for a specific dog, on a scale from 1 to 5. Not surprisingly, dogs that appeared teary-eyed, had 10 to 15% more responses from people, indicating that increased tear volume in dogs elicits an emotional response in their owners.

In some way, it doesn’t come as a big surprise to learn that dogs are capable of subtle body language such as this one, having in mind that they’ve evolved alongside humans and have picked up many useful traits along the road. For instance, dogs know that raising their eyebrows makes humans want to care for them – so-called “ puppy eyes” that work without fail. 

A lot remains a mystery, though. Do dogs have the same response when reunited with their canine friends or siblings? Do they rely on tears as a form of communication with other dogs? It’s definitely something interesting to think about, and the researchers behind this study hope to get the answer to these questions, as well.