Dogs understand us best and can understand human pointing gestures, much more so than chimpanzees. By Claudia Benismoun
Thousands of years of living with humans and domestication have most likely given our furry friends an evolved ability to pay attention to and understand most human visual communication. The main question is how flexible dogs' understanding of human communication really is. Dogs are more skillful in making use of human pointing gestures than wolves and even chimpanzees are. By investigating how dogs perceive such gestures and if they understand their referential nature, says Dr. Juliane Kaminski, a cognitive psychologist at the Max Planck Institute for Evolutionary Anthropology, investigated a dog's ability to comprehend other forms of human communication, including object labels and non-linguistic gestures such as symbolic and other non-directional representations. "We think that we are looking at a special adaptation in dogs to be sensitive to human forms of communication. There is multiple evidence suggesting that selection pressures during domestication have changed dogs such that they are perfectly adapted to their new niche, the human environment." Kaminski says. She suggests that dogs may even be born with this inherent gift, because 6-week-old puppies with no major training possess it.
During this study, Kaminski and her team compared how well chimpanzees and dogs understood human pointing. The person pointed at a visible object out of human reach, yet within the reach of the animal subject. If the chimp or dog retrieved the object, they would be rewarded with a treat. The chimps did not do well, ignoring the human gestures, even though they were interested and motivated to get the treats. The dogs did really well in the test.
Kaminski and her team concluded that the chimps failed to comprehend the referential intention of the human in the task. They did not see the pointing as important to their goal of receiving their treats, so they simply ignored the people during the study. "We know that chimpanzees have a very flexible understanding of others," says Kaminski. "They know what others can or cannot see, when others can or cannot see them." Kaminski suggests that wolves do not have this skill. "Wolves, even when raised in a human environment, are not as flexible with human communication as dogs. Dogs can read human gestures from very early ages on," says Kaminski.
Breed of the dog may also be an important factor in whether the dog easily understands human communications, according to Marta Gacsi, from the University of Eotvos, Hungary. Gasci worked with her researchers to examine the performance of different breeds of dogs in making sense of the human pointing gesture and found that gun dogs and sheep dogs were better than other hunting dogs, earth dogs (dogs used for underground hunting), livestock guard dogs, and sled dogs.
Kathryn Clark points out her pet rat, Friday, to Bella, an Italian Greyhound. Photo courtesy of Kathryn Clark.
In a study about intentional verses unintentional signaling to dogs, it was found that dogs clearly differentiate between the pointing and gazing cues by responding to intentional signals. Dogs differentiated acts in which a human communicated a location to them from situations in which a human produced similar but non-communicative movements in the same direction, meaning that dogs do not follow just any directional behavior of a human. The main cue that indicates a human's intent of communication is eye contact and the main cue indicating the human's intentional communicative act is also eye contact. This proves that eye contact is very important in dog-human interactions.
Nonetheless, another experiment suggests that eye contact was not very important to the dog, as he was still able to recognize that a cue was meant for the