Dogs Are Our Oldest Friends
Dogs follow and understand a shift in human gaze
Posted Feb 14, 2012
As I have explained in previous blogs, dogs were the first species to be domesticated by humans—and vice versa, of course. New evidence shows they were domesticated long before anyone thought: at least 32,000 years ago. (Just in case you are wondering, "domestication" involves genetic changes in the animal's make up while "taming" is a transient behavioral change. Domestication permanently transforms one species into a new one, while taming makes a single individual more amenable to interactions with humans.)
What does it mean that dogs are our oldest friends?
For one thing, it means we have worked out better systems of communication with each other. Experiments show that dogs are much more likely than wolves, even tame wolves, to follow and understand a shift in a human gaze. I believe this change in willingness to look at human faces and in ability to read human faces was one of the major changes that occurred as wolves were domesticated. Dogs understand how to communicate with humans, understand human communications, and actually think communicating with humans is a good thing (unless an unfortunate personal experience has persuaded them otherwise). Wolves don't, even though some wolves come to appreciate and communicate with some humans.
In fact, dogs are better at following a human gaze than great apes are. This fact is fairly astonishing because great apes are our closest relatives genetically but experiments carried out at the Max Planck Institute in Leipzig show that apes are more likely to follow the direction of a human face than of its eyes. Dogs are actually as good as human infants in following a shift in gaze and responding to it, whether or not the head or body of the human moves.
Humans are very probably adapted to communicate by changing the direction of their gaze, it turns out. One of the oddest things about humans is that, of all the primates, only humans have a prominent white sclera surrounding the colored iris of their eyes. Not only is the sclera or the eyeball darker in every other primate - often close in color to the iris an skin color - but more of the sclera is visible in humans because of the shape of our eyelids. The movement of the iris is thus very obvious in humans and not at all obvious in other primates. Putting all this together, the Japanese researchers who documented sclera color and eyelid shape concluded that humans were adapted to be able to communicate silently by shifting their gaze and following the gaze shifts of others. The advantage? Such silent communication might be very useful in coordinating hunting with other humans... and with dogs. This is a huge clue to one of the reasons wolves were domesticated into dogs: to help in hunting.
Thinking of dogs as fellow hunters reinforces one of our basic ideas about dogs: they are companions. They do things with us, go places with us, keep us company and help us. I like to think - no, I desperately hope - that we also help dogs and keep them company. It is certainly true that dog companions have enabled many humans to live fuller happier lives.
On February 2, 2012, Melissa Fay Greene published a remarkable story in The New York Times magazine called "Wonder Dog." She described in agonizing detail the struggles of the Winokur family who adopted two children from Russia, only to find that, at about age 3, the male child began to behave in inexplicable, destructive, and unacceptable ways. A diagnosis of fetal alcohol syndrome showed itself in minor physical traits but, behaviorally, in uncontrollable rages, violent, antisocial behavior, poor speech, low IQ, night terrors and other problems. When their son was 13, he needed a fulltime aide at school and his mother's constant attention at home. He was bigger physically but no better adjusted, no happier and in fact probably angrier. The family applied for a received a service dog from an agency called 4 Paws, run by Karen Shirk, a woman who is wheelchair-bound from myasthenia gravis, a neuromuscular disease. Shirk was turned down herself as "too disabled" by many agencies that place service dogs. She knows herself how much having a service dog transformed her life and now trains and places service dogs with others who are "too disabled."
Shirk repeated her own story by finding a dog for the Winokur boy. Within 24 hours of going home with Chancer, a genial golden retriever, the boy was able to sleep through the night without awakening in screaming terror; the dog's presence on the bed reassured him. The dog calms him during attacks of rage or fear, helps him break social barriers, gives him endless love and reassurance. The full story is amazing and I strongly recommend you all read it.
More than improved hunting, more than defense against other predators, warmth, hauling ability and the dozens of other benefits dogs have given us, this ability to be a constant loving companion is surely the greatest. No, I do not believe our Paleolithic ancestors ever envisioned what a service dog could do for a disabled child or adult; no, they didn't foresee that dogs would give unconditional love when they first raised a ferocious wolf puppy.
Funny how things work out sometimes.