If you’ve ever had a baby in your household, you know that humans are hard-wired to respond to the cries of an infant.
We can get used to tractor-trailers rumbling past our front door, or the 24-hour drone of a factory in the neighborhood, but there is something about the pitch and tone of a crying baby that cuts through all other noises and reaches down and sends an electric bolt to the nervous system. When Richard and Russell were in their cribs, their tiny, initial cries always jolted us instantly awake, no matter how tired we might have been.
Are humans similarly responsive to the barking of dogs? Kasey, unlike Penny, is a big barker. She barks when she wants food, she barks when food is being prepared, and she barks when she sees a stranger walking by or a cat stretching in our yard. Her shrill barks have an impact on my nervous system that is similar to a baby’s cries — they are disturbing and profoundly irritating.
There’s an evolutionary reason why we respond to baby cries, obviously. Human infants are helpless, and if evolution didn’t condition adults to react to their cries they would starve or be carried away by wolves, and the human species would cease to exist.
Could there similarly be an evolutionary reason why humans respond to a barking dog? Have dogs been domesticated for so long that natural selection has preferred humans who awaken when they hear the barking of man’s best friend and thereby can respond to whatever dangers the dog’s animal instincts have perceived?
I’m sticking with that theory, because it will be a lot easier to endure Kasey’s barking sprees if I believe that there is some Darwinism at work.