A research group at Azabu University and others has announced experimental results that dogs secrete more tears when they meet their owners again after a while.
A dog with tears in its eyes gives a favorable impression to people, and the research group said, ``It provides a hint to think about how dogs have built intimate relationships with humans in the process of domestication. ”.
A group led by Associate Professor Miho Nagasawa of Azabu University's Faculty of Veterinary Medicine investigated changes in the amount of tears in dogs when they were usually with their owners and when they met again after being away from them for more than five hours.
As a result, dogs produced an average of 15.9% more tears when reunited with their owners.
On the other hand, the amount of tears did not increase in non-owners.
In addition, when we quantified the impressions people received when we showed them pictures of dogs with watery eyes and dogs with watery eyes, we found that dogs with watery eyes gave a more favorable impression. .
In this study, it was also found that the hormone oxytocin, which is secreted when dogs engage in intimate behavior with humans, is related to the amount of tears they produce.
Associate Professor Nagasawa says, ``The way in which dogs show their emotions to their owners, making their eyes water, can be said to be one of the strategies to make people want to take care of them. So, it will give you a hint to think about how you have built a close relationship with people."
This research was published in the online version of the biology journal "Current Biology" on the 23rd, Japan time.