27-7 What do we know about thinking in other animals?

Other animals are smarter than we often realize. In her 1908 book, The Animal Mind, pioneering psychologist Margaret Floy Washburn argued that animal consciousness and intelligence can be inferred from their behavior. In 2012, neuroscientists convening at the University of Cambridge added that animal consciousness can also be inferred from their brains: “Nonhuman animals, including all mammals and birds,” possess the neural networks “that generate consciousness” (Low et al., 2012). Consider, then, what animal brains can do.

Even pigeons—mere birdbrains—can sort objects (pictures of cars, cats, chairs, flowers) into categories, or concepts. Shown a picture of a never-before-seen chair, pigeons have reliably pecked a key that represents chairs (Wasserman, 1995). By touching screens in quest of a food reward, black bears have learned to sort pictures into animal and nonanimal categories (Vonk et al., 2012). The great apes also form concepts, such as cat and dog. After monkeys learned these concepts, certain frontal lobe neurons in their brains fired in response to new “catlike” images, others to new “doglike” images (Freedman et al., 2001).

368

Until his death in 2007, Alex, an African Grey parrot, categorized and named objects (Pepperberg, 2009, 2012, 2013). Among his jaw-dropping numerical skills was the ability to comprehend numbers up to 8. He could speak the number of objects. He could add two small clusters of objects and announce the sum. He could indicate which of two numbers was greater. And he gave correct answers when shown various groups of objects. Asked, for example, “What color four?” (meaning “What’s the color of the objects of which there are four?”), he could speak the answer.

Psychologist Wolfgang Köhler (1925) showed that we are not the only creatures to display insight. He placed a piece of fruit and a long stick outside the cage of a chimpanzee named Sultan, beyond his reach. Inside the cage, he placed a short stick, which Sultan grabbed, using it to try to reach the fruit. After several failed attempts, he dropped the stick and seemed to survey the situation. Then suddenly (as if thinking “Aha!”), Sultan jumped up and seized the short stick again. This time, he used it to pull in the longer stick—which he then used to reach the fruit. Apes have even exhibited foresight by storing a tool they could use to retrieve food the next day (Mulcahy & Call, 2006).

Birds, too, have displayed insight. One experiment, by (yes) Christopher Bird and Nathan Emery (2009), has brought to life an Aesop fable in which a thirsty crow was unable to reach the water in a partly filled pitcher. See its solution in FIGURE 27.8a.

Like humans, many other species invent behaviors and transmit cultural patterns to their peers and offspring (Boesch-Achermann & Boesch, 1993). Forest-dwelling chimpanzees select different tools for different purposes—a heavy stick for making holes, a light, flexible stick for fishing for termites (Sanz et al., 2004). They break off the reed or stick, strip off any leaves, carry it to a termite mound, twist it just so, and carefully remove it. Termites for lunch! (This is very reinforcing for a chimpanzee.) One anthropologist, trying to mimic the animal’s deft fishing moves, failed miserably.

Researchers have found at least 39 local customs related to chimpanzee tool use, grooming, and courtship (Claidière & Whiten, 2012; Whiten & Boesch, 2001). One group may slurp termites directly from a stick, another group may pluck them off individually. One group may break nuts with a stone hammer, their neighbors with a wooden hammer. These group differences, along with differing communication and hunting styles, are the chimpanzee version of cultural diversity. Several experiments have brought chimpanzee cultural transmission into the laboratory (Horner et al., 2006). If Chimpanzee A obtains food either by sliding or by lifting a door, Chimpanzee B will then typically do the same to get food. And so will Chimpanzee C after observing Chimpanzee B. Across a chain of six animals, chimpanzees see, and chimpanzees do.

369

A baboon knows everyone’s voice within its 80-member troop (Jolly, 2007). Great apes and dolphins have demonstrated self-awareness by recognizing themselves in a mirror. So have elephants, which in tests also display their abilities to learn, remember, discriminate smells, empathize, cooperate, teach, and spontaneously use tools (Byrne et al., 2009). As social creatures, chimpanzees have shown altruism, cooperation, and group aggression. Like humans, they will kill their neighbor to gain land, and they grieve over dead relatives (Anderson et al., 2010; Biro et al., 2010; Mitani et al., 2010).

There is no question that other species display many remarkable cognitive skills. But one big question remains: Do they, like humans, exhibit language? In the next module, we’ll first consider what language is and how it develops.

Returning to our debate about how deserving we humans are of our name Homo sapiens, let’s pause to issue an interim report card. On decision making and risk assessment, our error-prone species might rate a C+. On problem solving and creativity, where humans are inventive yet vulnerable to fixation, we would probably receive a better mark, perhaps a B. And when it comes to cognitive efficiency, our fallible but quick heuristics and divergent thinking would surely earn us an A.