From Popular Science:
Most pet owners probably know what it’s like to cave to those “puppy dog” eyes—no matter the age of their canine. When your dog looks at you with that curled brow and doleful stare, it’s difficult not to give it a loving scratch or meaty treat. And why not: You and your furry friend have been conditioned by thousands of years of evolution for this moment, according to a growing body of research by biological anthropologists like Anne Burrows.
“Dogs are our closest companions,” she says. “They’re not closely related to us [as a species], but they live with us, they work with us, they take care of our children and our homes. So investigating different aspects of the dog-human bond, I thought, would help me understand human evolution and human origins.”