When a dog looks at you with big puppy-dog eyes, it' s hard for you to go away, and you may speak out " Awww" without hesitation. However, there' s a reason why you find a dog' s stare so attractive. That sweet stare actually causes the release of a particular hormone, or chemical messenger in the body. This hormone creates feelings of affection in humans. The same thing happens to dogs when people look back at them. Scientists believe this helps people and their four-legged friends bond, or feel connected. Scientists have wondered what causes dogs to lovingly stare at their owners. To find out, a team of researchers from Azabu University in Japan studied 30 owners and their dogs.
The researchers found that after the pets and their owners spent half an hour together, both showed a rise in oxytocin (催产素). One key role of this hormone in many animals is to promote bonding, like that between a mother and newborn. The increase of oxytocin didn' t happen, though, when scientists repeated the experiment with wolves and the humans who had raised them.
A second experiment also found that if dogs were given oxytocin, they looked at their owners longer. Scientists aren' t sure exactly why, but this reaction occurred only with female dogs. Their owners' oxytocin levels also rose as a result.
The result of these experiments might help answer an age-old question: How did the fearsome wolf ancestor of modern dogs turn into man' s best friend? Takefumi Kikusui, an animal scientist who worked on the study, thinks that the change happened when dogs first became domestic (驯养的).
According to Kikusui, there may have been a small group of wild dogs that were naturally friendlier. " Humans are very sensitive to eye contact. By using this special communication tool, the dogs are able to win over our hearts. If they are more likely to make eye contact, it would be easier for them to bond with dog owners," Kikusui said.
