One of the first things a person does when she or he gets a dog is teach the dog tricks — sit, stay, shake, roll over — so it seems like a given that we humans can communicate with dogs. But can dogs intuit what humans are thinking?
Most dog owners would unequivocally answer “yes”, and it turns out there’s scientific evidence to back them up. For my first post, I’d like to talk about one of my favorite research areas in animal cognition: the use of human social cues by dogs.
The experiment is simple: a person places a piece of food under one of two opaque cups (merely pretending to place the food under the other cup). Next, the person uses some sort of cue (pointing, looking at, etc.) to indicate which cup the food is under. The dog then approaches the cup he thinks contains the food, and the person lifts that cup — if the dog is right, he gets the food as a reward. The whole process is repeated many times and if the dog performs significantly better than chance (he chooses the food “baited” cup more than half the time), then we can conclude that he understood the communicative intent of the cue used by the person (i.e. that the person was indicating where the food was located).
Researchers found that dogs chose the “baited” cup significantly more often when people pointed at, looked at, or tapped that cup. This indicates that the dogs understood not only that the people were using those cues to communicate something, but also WHAT the people were communicating. The dogs had never been trained to associate the cues with finding food — they were able to intuit the intent of the person giving the cue.
This experiment suggests that, at some level, dogs may be able to think about what’s going on in our heads. That’s a fascinating finding in and of itself (though probably an obvious one to dog owners), but here’s where it REALLY gets interesting.
Researchers tried the same experiment with chimpanzees, one of our closest genetic relatives.
[Slight tangent: The cognitive abilities of chimps and other primates are often studied in order to better understand the evolution of human cognitive abilities. If chimps share a particular cognitive ability with humans, then we can infer that that ability evolved before humans and chimps evolved into separate species. If, on the other hand, humans have a cognitive ability that is not shared with chimps, then that ability probably evolved after chimps and humans separated on the evolutionary tree.]
So researchers wanted to see if chimps could also understand human social cues. They did the exact same experiment as was done with the dogs, but the results were very different: the chimps were unable to use humans’ gestures to find the food!
These results posed an interesting puzzle: how are dogs able to use human social cues, while our closest evolutionary and genetic relatives cannot?
The answer to that question is another blog post in itself (at least), so check back here next week for that! In the meantime, here’s a video that’s a nice summary of everything in this post (including a demo of the experiment). The researcher in the video is Dr. Brian Hare, who runs the Canine Cognition Center at Duke University. He conducted one of the first studies investigating dogs’ understanding of human social cues (Hare et al. 1998), and has since done many experiments extending that research.
For those interested in reading the original scientific papers of this research, Hare et al. (2002) is a great place to start — it includes comparison experiments between dogs of different ages, dogs and chimps, and dogs and wolves (preview for next week!). You can find most of Dr. Hare’s papers on canine cognition (including those mentioned above) here.
Other related papers:
Agnetta, Bryan, Brian Hare, and Michael Tomasello. “Cues to food location that domestic dogs (Canis familiaris) of different ages do and do not use.” Animal cognition 3.2 (2000): 107-112.
Itakura, Shoji, et al. “Chimpanzee use of human and conspecific social cues to locate hidden food.” Developmental Science 2.4 (1999): 448-456.
Miklósi, Ádám, et al. “Use of experimenter-given cues in dogs.” Animal Cognition 1.2 (1998): 113-121.