When Brian Hare started college in 1994, he apprenticed himself to a top chimpanzee researcher. His mentor, Michael Tomasello, was just beginning to investigate whether chimpanzees can understand what another chimp—or perhaps even a human—is thinking. Hare said such a skill couldn't be that difficult. After all, he told Tomasello, "my dog does that." Tomasello looked skeptical. And then he spoke the words that often inspire scientific discovery: "Prove it."
From This Story
So Hare did. Using his parents' garage as his lab and the family dogs as his research subjects, the 19-year-old devised a simple experiment. When a dog wasn't watching, he hid a treat beneath one of two plastic cups. He then showed the dog the cups and either pointed to or looked at the one covering the treat. "They knew exactly what to do," he recalls. "They headed straight for the right cup and got their treat." (The dogs couldn't smell where the food was hidden.)
Although the results of Hare's experiment might not have surprised many dog owners, the study caught the attention of scientists who study animal cognition. At the time, most were hesitant to credit any animal with the ability to infer what another being is thinking—only humans were supposed to have that facility.
"These experiments test whether an animal is able to think about the thoughts of others, as we do," says Hare. "If you hide food and look at it, giving the dog a social cue, it should understand: ‘He's looking at where the food's hidden. He wants me to find it. And he knows where it's hidden, because he hid it.' "
But Hare didn't set out to study man's best friend—chimpanzees were what made him want to be a scientist. He dreamed of heading to the dense forests of East Africa, like his hero, Jane Goodall, to follow and study chimpanzees. "I'd seen a film about Jane when I was about 9," he recalls. "I thought, ‘Wow! I'm going to do that too!'"
That's why he joined Tomasello at Emory University's Yerkes National Primate Research Center in Atlanta. Oddly, though, when he and Tomasello investigated the ability of chimpanzees to follow a person's pointing finger or the direction of his gaze, the apes performed more poorly than the dogs. "I was surprised," Hare says. "After all, chimps are our closest relatives, and when you spend any time around them, you immediately see how smart and social they are."
Perplexed at the chimps' inability to follow a simple social cue, Hare resolved to delve deeper into their minds when he went to Harvard for his doctorate. He thought he'd go off to Uganda with Richard Wrangham, a primatologist who studies chimpanzees in Kibale National Park in Uganda. "But then Wrangham said he wanted me to go to Siberia to study some foxes," Hare says. "I thought, ‘Oh my god, I must have blown it! He's banishing me—I'm being exiled in Siberia.'"
Actually, Wrangham wanted Hare to look into an intriguing experiment at the Institute of Cytology and Genetics near Novosibirsk, Russia. Since 1959, researchers there had been breeding silver foxes for a single trait: compatibility with people. Foxes who readily approached people were allowed to breed; those showing fear or aggressive behaviors were disqualified from the gene pool (that is, made into fur coats). After 30 generations, the foxes' behavior had utterly changed. They'd not only lost their fear of people, but they were eerily like dogs. They ran up to people and wagged their tails. They evolved floppy ears, patterned coats, curly tails, and smaller teeth and bones.
Recent genetic studies have shown that dogs were domesticated from wolves—not foxes—so the scientists at Novosibirsk weren't simply recapitulating the origin of domestic dogs; they wanted to know how tameness could be bred. Wrangham suspected that the tame foxes could help Hare understand dogs. "I thought that the mere reduction of aggressiveness, resulting from domestication, might be the reason that dogs paid better attention to humans," says Wrangham. "I knew this hypothesis could be tested by studying these foxes and that Brian would think up a clever, creative experiment."
Hare already suspected that dogs had evolved the ability to understand human pointing signals sometime after they were domesticated from gray wolves about 15,000 years ago. "Wolves are more like chimps on these tests," says Hare. "From the first trial, the dogs—even puppies—just crushed the wolves. From the time puppies open their eyes, they can do it; it's not something they have to learn. And that means their ability to read human social cues must be something that has evolved since living with us."