Are We Smart Enough to Know How Smart Animals Are?(65)
Despite their deep-seated fear, the apes would set out on a long trek to a specific fig tree where they had recently eaten. Their goal was to beat the early fig rush. These soft, sweet fruits are favored by many forest animals, from squirrels to flocks of hornbills, so that an early arrival would be the only way to take advantage of the abundance. Remarkably, the chimps would get up earlier for trees far from their nests than for those nearby, arriving at about the same time at both. This suggests calculation of travel time based on expected distances. All this makes Janmaat believe that the Ta? chimpanzees actively recall previous experiences in order to plan for a plentiful breakfast.5
The Estonian-Canadian psychologist Endel Tulving defined episodic memory as the recall of what happened at which place and at what time. This has prompted research into memory of the three W’s of events: their what, when, and where.6 While the above ape examples seem to fit the bill, we need more tightly controlled experiments. The first challenge to Tulving’s claim that episodic memory is limited to humans came from precisely such an experiment, not on apes, but on birds. Together with Anthony Dickinson, Nicky Clayton took advantage of the hoarding tendency of her western scrub jays to see what they remembered about cached foods. The birds were given different items to hide, some perishable (waxworms), others durable (peanuts). Four hours later the jays looked for the worms—their favorite food—before they looked for nuts, but five days later their response was reversed. They didn’t even bother to find the worms, which by that time would have spoiled and become distasteful. They did remember the peanut locations after this long interval, though. Odor could be ruled out as a factor, because by the time they were tested, the scientists recorded search patterns in the absence of food. This study was quite ingenious and included a few additional controls, leading the authors to conclude that jays recall what items they have put where and at what point in time. They remembered the three W’s of their actions.7
The case for episodic memory in animals was further strengthened when the American psychologists Stephanie Babb and Jonathon Crystal let rats run around in an eight-armed radial maze. The rodents learned that once they had visited an arm and eaten the food in it, it would be permanently gone, so there would be no point returning to it. There was one exception, though. They occasionally found chocolate-flavored pellets, which would be replenished after long time intervals. The rats formed an expectation about this delicious food based on where and when they had encountered it. They did return to those specific arms, but only after long intervals. In other words, the rodents kept track of the when, what, and where of chocolate surprises.8
Tulving and a few other scholars were hardly satisfied with these results, however. They fail to tell us—the way Proust did so eloquently—how aware the birds, rats or apes are of their own memories. What kind of consciousness, if any, is involved? Do they view their past as a piece of personal history? Since such questions are unanswerable, some have weakened the terminology by endowing animals only with “episodic-like” memory. I don’t agree with this retreat, however, since it gives weight to an ill-defined aspect of human memory known only through introspection and language. While language is helpful to communicate memories, it is hardly what produces them. My preference would be to turn the burden of proof around, especially when it comes to species close to us. If other primates recall events with equal precision as humans do, the most economic assumption is that they do so in the same way. Those who insist that human memory rests on unique levels of awareness have their work cut out for them to substantiate such a claim.
It may, literally, be all in our heads.
The Cat’s Umbrella
The debate about how animals experience the time dimension heated up even further in relation to the future. Who’d ever heard of them contemplating events that lay ahead? Tulving drew on what he knew about Cashew, his cat. Cashew seems capable of predicting rain, he said, and is good at finding places to take cover, yet “never thinks ahead and packs an umbrella.”9 Generalizing this astute observation to the entire animal kingdom, the eminent scientist explained that while animals adapt to their present environment, they sadly fail to imagine the future.
Another human uniqueness proponent noted that “there is no obvious evidence that animals have ever agreed on a five-year plan.”10 True, but how many humans have? I associate five-year plans with central government and prefer examples drawn from the way both humans and animals go about their daily business. For example, I may plan to buy groceries on my way home, or decide to surprise my students with a quiz next week. This is the nature of our planning. It is not unlike the story with which I opened this book regarding Franje, the chimpanzee who gathered all the straw from her night cage to build a warm nest outdoors. That she took this precaution while still indoors, before actually feeling the cold outside, is significant because it fits Tulving’s so-called spoon test. In an Estonian children’s story, a girl dreams of a friend’s chocolate pudding party where she can only watch other children eat, because everyone has brought their own spoon, and she has not. To prevent this from happening again, she goes to bed that night clutching a spoon. Tulving proposed two criteria to recognize future planning. First, the behavior should not follow directly from present needs and desires. Second, it should prepare the individual for a future situation in a different context than the current one. The girl needed a spoon not in bed, but at the chocolate pudding party she expected in her dream.11