Are We Smart Enough to Know How Smart Animals Are?(71)
Mike was impressed by Sally’s research showing that chimps can’t get the reversal right with actual candies. This was obviously a matter of self-control. When he tried the same test on his own chimps, they didn’t pass either. Sally’s idea to replace the candies with numbers was brilliant. Whether it is the symbolizing or just the removal of the hedonic property, chimps trained with numerals were really good at it. When I asked if the same had ever been tried with children, Mike’s answer reflected the deep concern of students of animal cognition with fair comparisons: “It may have been tried, I don’t recall, but they probably explained it to the kids, and I would prefer that nothing is explained. We can’t explain it to the apes either.”
Know What You Know
The claim that only humans can mentally hop onto the time train, leaving all other species stranded on the platform, is tied to the fact that we consciously access past and future. Anything related to consciousness has been hard to accept in other species. But this reluctance is problematic: not because we know so much more about consciousness, but because we have growing evidence in other species for episodic memory, future planning, and delayed gratification. Either we abandon the idea that these capacities require consciousness, or we accept the possibility that animals may have it, too.
The fourth spoke on this wheel is metacognition, which is literally cognition about cognition, also known as “thinking about thinking.” When the contestants in a game show are allowed to pick their topic, they obviously name the one they are most familiar with. This is metacognition in action, because it means they know what they know. In the same way, I may answer a question by saying “Wait, it’s on the tip of my tongue!” In other words, I suspect that I know the answer, even though it’s taking me time to recall it. A student raising her hand in class in reaction to a question is also relying on metacognition, because she only does so if she thinks she knows the solution. Metacognition rests on an executive function in the brain that allows one to monitor one’s own memory. Again, we associate these processes with consciousness, which is exactly why metacognition, too, was deemed unique to our species.
Animal research in this area began perhaps with the uncertainty response noticed by Tolman in the 1920s. His rats seemed to hesitate before a difficult task as reflected in their “lookings or runnings back and forth.”36 This was most remarkable, since at the time animals were thought to simply respond to stimuli. Absent an inner life, why be in turmoil about a decision? Decades later the American psychologist David Smith gave a bottlenose dolphin the task to tell the difference between high and low tones. The dolphin was an eighteen-year-old male named Natua, in a pool at the Dolphin Research Center in Florida. As in Tolman’s rats, Natua’s level of confidence was quite manifest. He swam at different speeds toward the response, depending on how easy or hard it was to tell both tones apart. When they were very different, the dolphin arrived with such speed that his bow wave threatened to soak the electronics of the apparatus. They had to be covered with plastic. If the tones were similar, though, Natua slowed down, waggled his head, and wavered between the two paddles that he needed to touch in order to indicate a high or low sound. He didn’t know which one to pick. Smith decided to make a study of Natua’s uncertainty, mindful of Tolman’s suggestion that it might reflect consciousness. The investigator created a way for the animal to opt out. A third paddle was added, which Natua could touch if he wanted a fresh trial with an easier distinction. The tougher the choice, the more Natua went for the third paddle, apparently realizing when he had trouble coming up with the right answer. Thus the field of animal metacognition was born.37
Investigators have essentially followed two approaches. One is to explore the uncertainty response, as in the dolphin study, while the other is to see if animals realize when they need more information. The first approach has been successful with rats and macaques. Robert Hampton, now a colleague at Emory University, gave monkeys a memory task on a touchscreen. They would first see one particular image, say a pink flower, then face a delay before being presented with several pictures, including the pink flower. The delay varied in length. Before each test, the monkeys had the choice to either take it or decline it. If they took the test and correctly touched the pink flower, they gained a peanut. But if they declined, they only got a monkey pellet, a boring everyday food. The longer the delay, the more the monkeys declined taking the test despite its better reward. They seemed to realize that their memory had faded. Occasionally, they were forced to take a trial without a chance of escape. In those cases they fared rather poorly. In other words, they opted out for a reason, doing so when they couldn’t count on their memory.38 A similar test with rats gave similar results: the rats performed best on tests that they had deliberately chosen to take.39 In other words, both macaques and rats volunteer for tests only when they feel confident, suggesting that they know their own knowledge.
A rhesus macaque knows that food has been hidden in one of four tubes, but he has no idea which one. He is not allowed to try every tube and will get only one pick. By bending down to first peek into the tubes, he demonstrates that he knows he doesn’t know, which is a sign of metacognition.
The second approach concerns information seeking. For example, jays placed at peepholes were given an opportunity to watch food—waxworms—being hidden before they were allowed to enter the area to find it. They could look through one peephole to see an experimenter put a waxworm in one of four open cups, or they could look through another to see another experimenter with three covered cups plus one open one. In the second case, it was obvious where the worm would end up. Before entering the area to find the worm, the birds spent more time watching the first experimenter. They seemed to realize that this was the information they needed most.40