In this chapter I will give textual evidence for several claims. First, I will argue that there is a pop culture paradigm that demands
surprising similarity between humans and nonhuman primates in terms of their mental lives, especially in terms of cognition and emotionality. As I discuss headlines from popular media,
1 I will review the originating scientific studies of nonhuman primate cognition and note that they too aim at similarity finding and are actually structured to reveal similarity rather than to uncover disparity or profound difference.
2 I will finally suggest that similarity seeking ultimately narrows the way science is being done and propose, with Uexküll (1985 [1909]), that a good cognitive ethology should also incorporate studies that concentrate on a broader, less anthropocentric range of cognition and emotional states and that such a science will prove to be more useful than we might immediately imagine.
Surprising Similarity in Scientific Studies and the Media
Which similarities between nonhuman primates and humans are surprising, and which are not? Evolutionarily speaking, all higher organisms must be able to navigate using the senses and avoid danger. So we would not be surprised if we were told that cotton-topped tamarins can see or feel or that orangutans can sense heat and move toward the shade on a sunny day. We are also not surprised if we hear that rhesus monkeys express fearful behaviors or that great apes can demonstrate aggression (Balcombe 2006:19).3 Why not? First, we come from a long Western tradition that expects certain things of animals and not others. Living a life based on sensations and primal emotions such as fear and aggression is the paradigmatic case of living an animalistic life rather than a thoughtful, reflective human life. René Descartes (1999 [1637]) claimed, in the Discourse on Method, that animals do “not act on the basis of knowledge, but merely as a result of the disposition of their organs” (p. 40). To be governed by the physical drives and bodily passions is the Cartesian definition of what it is to be animal and to be unconscious. But Descartes did not found this dividing line. Aristotle (1941 [322 bc]) writes in De Anima, “In all animals other than man there is no thinking or calculation” (book 3, part 10, p. 597). Immanuel Kant (1981 [1785]), in the Groundwork, dismissed the moral status of animals: “If they are irrational beings, [they have] only a relative value as means, and are therefore called things; rational beings, on the contrary, are called persons, because their very nature points them out as ends in themselves, that is as something which must not be used merely as means” (pp. 35–36). The dividing line between humans and animals continues in the present day, where we find Daniel Dennett (1996) arguing that animals often have “Skinnerian” or “Popperian” but not “Gregorian” minds. He claims they can learn through stimulus and response (Skinnerian), as well as can model reality internally (Popperian—so their hypotheses can die in their stead), but they are fundamentally unable to incorporate their tools into their conceptual structure and thus modify their mental landscapes through the use of technology. He claims that “we, and only we, have developed [a technique of] deliberately mapping our new problems onto our old problem-solving machinery” (p. 145). For Dennett, animals simply do not have the cognitive equipment that humans do. From this brief survey, we can see that major philosophers across several time periods have argued that there is a clear dividing line between human and beast, and that dividing line has something to do with rationality, cognition, thoughtfulness, self-reflection, and the higher, more esoteric forms of mentality. As a result of participating in this culture of teachings, we tend to expect basic similarity between human and animal in the ability to perceive the world and feel primitive emotions and drastic difference in cognition. That which violates these expectations, then, is what I will take to be surprising.
Headlines are designed to grab our attention, and thus the familiar line mocking the news media “if it bleeds, it leads” is well-known to all. Headline makers are alert for discoveries that somehow bump up against our traditional beliefs and expectations. This is as true for news in the science of animal minds as it is for news in the human world, and headlines often reveal the traditional presuppositions of human-animal division: rationality, cognition, self-reflection, etc. For example, note these headlines about parrots who can do mathematics, “Parrot Prodigy May Grasp the Concept of Zero” (Pickrell 2005), or speak as humans do, “Counting, Speaking Parrot Alex Dies” (2007), or apparently join the ranks of MENSA, “Alex, Genius Parrot Who Dazzled Scientists Dead at Thirty-one” (“That Damn Bird” 2007). These headlines show we have not changed much in what seduces our attentions since the social sensation of the horse, Clever Hans, who was purported to count, add, and subtract. Likewise, reports on New Caledonian crows who make their own tools lead with headlines such as “Crow Reveals Talent for Technology” (Pain 2002) and “Crows Match Great Apes in Skilful Tool Use” (Randerson 2007).4 But birds are not the only ones that can surprise and excite us, and the abilities of mammals everywhere have a full share of the media. Headlines spotlight the symbolic skills of vervet monkeys who practice gestural communication in “Monkeys Terrorize Village in Kenya” (Njeri 2007), “African Monkeys Sexually Harass Women” (Kalla 2007), “Sexist Monkeys Terrorize Village” (Rolen 2007), and the very clever “Monkeys Ape Sex Harassment” (Neighbour 2007). The media is likewise alert to dolphins, those cooperative social predators of the sea who understand syntax: “Dolphin Whistles Offer Signs of Language Ability” (2000). And the spotlight falls on creatures from chimpanzees to elephants who gaze at their own mirror reflections: “Mirror Test Reveals Elephants Are No Dumbos” (2006) and “Dolphin Self-Recognition Mirrors Our Own” (Wong 2001). We can see that surprising similarities across the animal kingdom have caught the attention of reporters in a variety of popular venues.
Of course, there are headlines based on differences, specifically, on astounding abilities some animals have that far outstrip those of humans.5 After all, if headlines sell media subscriptions based on generating surprise and interest, then differences are good candidates for startling the public into reading the article. Headlines showcasing remarkable differences include, “Weird Shrimp Has Astounding Vision” (2008), “Cancer-Sniffing Dog to Be Cloned” (Chan-Kyong 2008), “Cat Plays Furry Grim Reaper at Nursing Home” (2007), “Chihuahua Saves Boy from Rattlesnake” (2007), “Electric Shark Snot” (2007),6 and “Animals That Glow in the Dark—Bioluminescence Is Not New Technology” (Bourque 2008). This essay is not arguing that such astounding differences and their corresponding headlines do not exist. Rather, I am suggesting that one common media project is that of highlighting (and perhaps exaggerating) surprising similarity. There may well be several other media projects aimed at other aspects of animal behavior and cognition, though I suspect that these too are founded on assumptions about what humans can or cannot do and go on to measure animals by the same yardstick.
Primate Similarities in Cognition
While all animals are candidates for presenting us with some sort of surprising similarity, primates are ideal candidates for bringing us subtle and sophisticated similarities because they are closely related to us in evolutionary terms and bear both physical and sometimes social resemblances to humans.
“Go Ahead, Rationalize, Monkeys Do It Too” is a New York Times science section headline from November 6, 2007. Far beyond mere addition or toolmaking, rationalization is a sophisticated mental feat in self-deception—we gather evidence that our decisions are good while ignoring evidence to the contrary, we paint ourselves in a rosy light to preserve a sense of self or self-efficacy that may not be entirely true. What is a compelling human example? In a decades-old study by Brehm (1956), adult humans were asked to rank the desirability of different household items and then asked to choose one (for example, juicer versus toaster). Upon selecting one—e.g., the juicer—the subjects were once again asked to rank the desirability of the toaster. Without fail, the unchosen item was later ranked as less desirable than it had been ranked originally, suggesting that we unconsciously bolster our choices with rationalizations to place them in the best light. In the partner primate study (Egan, Santos, and Bloom 2007), Capuchin monkeys who preferred red, green, and blue M&Ms equally were asked to select a single color. Once red was chosen over blue, for example, the monkeys would consistently favor other colors over blue, even though before the forced choice, the blue ones were seemingly just as tasty. So, capuchins seem to devalue the item not chosen just as humans do, thus avoiding the cognitive dissonance known as “buyer’s remorse.”
In a moment, I will point out alternative interpretations for these study results that may be slightly less anthropocentric, but first I note that the primate study is a fairly precise imitation of the human study. That is, this primate research clearly sought to reproduce results found in a human study: The experimental structure is similar, and the understanding of the results appears to have been developed from the standpoint of the human study. While science must bootstrap from one study to the next, this example suggests that we use established facts and interpretations of human behavior to set up our exploration of animal behavior and nonhuman mental states.
I now turn to a brief complication of the standing interpretation of these experimental results. Far from establishing rationalization, these experiments could easily support alternative interpretations. For example, when forced to choose, one may suddenly find oneself weighing all sorts of attributes that were previously not present to consciousness. Perhaps I liked the toaster and the juicer equally well until I had to select one, at which point I decided that I toast items far more often than I juice, that the juicer takes more counter space, and that I have a supply of bagels in the freezer already, while fresh fruit has become rather expensive. That is, further reflection may reveal reasons that are not rationalizations, but legitimate and thoughtful indicators of preference. To interpret these experimental results as indicative of rationalization that protects us from buyer’s remorse is to take a rather cynical (and human) approach to the data.
Likewise, there is more than one interpretation of the capuchin behavior. When allowed only one M&M, perhaps the capuchins do favor the taste of the red dye over the blue, or perhaps they favor a specific experimenter who is offering them the forced red choice. We should not assume so readily that capuchins do not taste the M&M dyes or that they do not have social motivations for their behaviors. The correct placement of Occam’s razor here is quite unclear. Should we consider their behaviors to be based on gustatory sensations? On social proclivities? Or on a tendency to rationalize their choices? The fact that the researchers chose to mirror the interpretation and conclusion of the human experiment rather than keep to the probably more conservative interpretation of sensory preference (or even social preference in a social mammal) shows a departure from the Aristotelian and Cartesian tradition that can be explained by a bias toward finding surprising similarity between the species.
Another interpretive problem appears when we explore the structure of the study more closely. In this study baseline preference was measured by how long the capuchin subjects took to retrieve individual M&Ms. Since individual M&Ms were presented, a hungry monkey might find any color equally desirable and reach for it equally quickly. After being forced to choose, the fact that the monkeys will favor the color they previously chose is not necessarily a sign of rationalization. They may simply follow a conservative paradigm of selecting again what has been successful in the past. Well-trained laboratory monkeys who have been subjects of many types of cognitive tests may well believe that remembering what has been presented in the past, and selecting it again, will lead to further rewards. (This is a common cognitive paradigm known as win-stay—one continues to choose what one has been rewarded for choosing. Such behaviors are often rewarded, as win-stay behavior is considered to be rational and revelatory of mental processes common to executive function.) But the study was explicitly designed to attempt to measure a common response to cognitive dissonance and was specifically modeled according to the choices the humans made between toasters and juicers in the original cognitive dissonance study. In their article, Egan, Santos, and Bloom (2007) ask, “Are humans unique in their drive to avoid dissonant cognition, or is this process older evolutionarily, perhaps shared with nonhuman primate species?” (p. 978). Clearly, the researchers were motivated by the possibility of finding commonality—surprising similarity in cognitive process—between humans and capuchins. Thus the popular headline emerging from the cognitive dissonance study, “Go Ahead, Rationalize, Monkeys Do It Too,” is not so far from the intentions of the researchers, and the goal of finding similar behavior toward cognitive dissonance obscures both other possible similar reactions and potential cognitive differences that can manifest in the same reaction.
Another example will serve to illustrate similar points. In an article with the headline “Young Chimp Beats College Students” (Ritter 2007), researchers report that chimps do better on tests of short-term memory than human adults. The popular article explicitly notes that we generally think that humans are overall better at “executive function” type cognitive tasks than nonhuman primates, so to discover that chimps actually outperform us is surprising. In the partner scientific article, the authors assert this same motivation for their research when they note, “The general assumption is that, as with many other cognitive functions, it [chimpanzee memory] is inferior to that of humans; some data, however, suggest that, in some circumstances, chimpanzee memory may indeed be superior to human memory” (Inoue and Matsuzawa 2008). While one might debate exactly what it means to have a better memory (the chimp performance advantage was not in accuracy but in speed—chimps could press a series of presented numbers faster than we humans could), the explicit research agenda was to explore the similarities in cognition between humans and chimps, and the authors of both articles work on the implicit assumption that a case in which chimps outperform humans would be surprising.
In a third popular article, “Primates Expect Others to Act Rationally” (Lavoie 2007), we find that a variety of primates, ranging from cotton-topped tamarins to chimps to rhesus macaques, seem to respond to the gestures of people using theory of mind, that is, they respond to actions using behaviors consistent with their attributing intentionality to humans. These primates could distinguish between the case of an experimenter intentionally tapping on a container to indicate that it was full of food and unintentionally knocking it with a swinging or flopping hand. The second experiment added to these findings, indicating that these primates distinguished between an experimenter “pointing” to a container with an elbow when her hands were full and an experimenter with empty hands motioning the elbow accidentally toward a food container. Like humans, tamarins, chimps, and macaques assumed that an elbow would be used for pointing when the hands were full, but that hands were more likely to be used for pointing if they were free. While it is not clear that these experiments actually test for “rationality” in any classical sense of the term, they do seem to indicate that these primates perceive and act on goal-directed behavior and treat certain human gestures as intentional.
In the companion scientific article (Wood et al. 2007), the authors explicitly note that their experiments were designed to reveal whether these primates have the same “mindreading” capabilities as humans do, and whether they use them in the same ways. While the researchers make no specific claims about the rationality of their subjects, they do note evidence for both theory of mind and an understanding of intentional, goal-directed behavior and suggest that the ability to use such an “intentional stance” may have evolved over forty million years ago in our shared ancestors.7 The researchers pose the puzzle early in the article that while “humans are capable of making inferences about other individuals’ intentions and goals … presently unclear is whether this capacity is uniquely human or is shared with other animals” (Wood et al. 2007:1402).
Such findings in nonhuman primate cognition mirror other recent findings regarding the emotional landscape of nonhuman primates, showing that chimps become more frustrated when an experimenter intentionally teases them by offering food and then taking it away than they do when an experimenter offers food and then accidentally drops it (Call et al. 2004). In popularized studies of surprising emotional sophistication such as “Chimps Get Angry, Not Spiteful” (2007), we find that chimps seek revenge on those who purposefully steal food (that is, they try to destroy the food), but they leave in peace those who are just luckier than they are to get food. Chimps would collapse a table containing food when a thieving chimp was eating, but when food was simply made unavailable to them but available to other chimps, the others were left to eat in peace. This media article suggests that chimps are acting on a rather sophisticated and shared principle of just behavior, leaving punishment for thieves but otherwise accepting fate. The original scientific article, “Chimpanzees Are Vengeful But Not Spiteful,” explicitly states the exploration of a human behavioral parallel as a motivation for the study when they explain, “People will willingly suffer a cost to punish others…. However, it is not known whether animals other than humans react to harmful actions directed toward them by retaliating against the perpetrator, and whether they react to disproportionate outcomes by behaving spitefully toward the fortunes of others” (Jensen, Call, and Tomasello 2007). The authors are curious about the evolution of a sense of justice and whether humans uniquely will sacrifice themselves in order to achieve punishment of wrongdoers. In a rare moment the researchers conclude that the chimps do not achieve exactly the same responses as humans.8
These examples strongly suggest that researchers often participate in actively attempting to uncover surprising similarity between human and nonhuman primate cognition. This is not, in itself, a completely wrongheaded endeavor. Seeking surprising similarity might be scientifically valuable, as clearly the development of shared capacities over millennia gives us clues as to the importance of those capacities for survival as well as their environments of origin, their lineage, and their relative success as adaptive capacities. Science ought to commit itself to potentially uprooting biases in traditional thought, and we progress by recognizing when our a priori commitments are not supported by empirical evidence. However, when we search for similarity we place ourselves at the center of the research and explore animals in relation to us. This may interfere with our ability to discover animals’ cognitive abilities and propensities on their own terms, in their own context, and in light of their own goals and biases. Thus the hopeful directive of this chapter is that we ought to try to notice when we are being self-centered and strive to do better in order to best serve our processes of discovery.
Anthropocentrism in Measuring Intelligence and Emotionality
All these studies reveal presuppositions we have for defining and measuring emotionally sophisticated or intelligent behavior. Intelligent creatures, according to these experiments, do such things as use symbols, attribute mental states to other creatures, and have good memories. Likewise, emotionally sophisticated creatures tend to reduce cognitive dissonance and displays of frustration, anger, and spite through rationalization (that is, they control spiteful urges). Clearly, these are limiting and distorting parameters for both intelligence and emotionality. While intelligence probably does demand symbolic manipulation and memory, the attribution of mental states to other creatures (theory of mind) may well be only a likely rather than an essential component of intelligence and not at all a prerequisite. As humans it is easy for us to conflate intelligence with rationality and both of these with the ability to attribute mental states to others, but other important components of intelligence, such as the ability to problem solve and exhibit flexible behaviors when presented with new stimuli, may be independent of symbol use and intentionality attributions. Our form of life, as Wittgenstein might call it, pulls us to navigate the world through intentionality and symbolic thought. Similarly, we humans often take subtle shades of emotion (beyond the simpler feelings of fear, anger, desire, and contentment) to indicate cognitive sophistication, and so we find it easy to look for the more complicated feelings of spite or jealousy (or the ability to control spite and jealousy) in similar animals.
This approach, while important in terms of noting evolutionary points of similarity as well as evolutionary origins of certain traits and abilities, is inadequate in at least three respects. First, for such experiments to reveal similar traits, the subjects must also be cooperative, food motivated, trusting, and familiar with people, as well as implicitly accepting of basic principles of folk physics, object permanence, cause and effect, and the correctness of generalizing from past experience; and they also must generalize in specific ways along salient features of the experiments. That is, relevant similarities are assumed in order for us to prove other relevant similarities. Of course, with Quine (1977), we might simply think that all experiments test multiple, conceptually linked hypotheses and that results confirm or disconfirm complex hypothetical premises as wholes rather than as atomistic postulates. We have no way of knowing, given disconfirming evidence, exactly which of our dozens of assumptions is incorrect or faulty. But we can step back from the entire project and note that it is motivated by the discovery of similarity and that it assumes concomitant similarities in the psychology of nonhuman primates. We can note that other projects that both assume and seek difference are equally possible and perhaps equally valuable.
Second, these assumptions about primate cognition stand in partial contrast to what we explore in humans using standard IQ tests such as the Stanford Binet, making the claims about animal intelligence incomparable to our studies on human intelligence. The Binet focuses on vocabulary, mathematical problem solving, pattern recognition, and visual and verbal memory, and human children are ranked in terms of their general intelligence as a result of their performance on these subsections of the test. Of course, the Binet has been widely criticized as being a measure of enculturation, whiteness, and relative affluence as well as exposure to specific educational opportunities; however, it also is a proven measure of relative successfulness and achievement later in life. Given the importance of Binet scores to children, parents, and scientists studying intelligence, we should perhaps be surprised that ethologists have not in recent years developed any type of cognitive test that is particularly parallel to vocabulary or word definition tasks, or mathematical problem solving, when they have approached the study of primate cognition.
Some of this is because primates are not verbal in the way that we are and so cannot be asked to define terms or solve word problems. Some of this is because training primates to complete far simpler tasks takes years and significant training talent. And I think some of this is because we have no clear idea of what constitutes successful achievement in the later lives of nonhuman primates. The Binet was developed to predict scholastic achievement, which it does to some extent, but it has proven to be a fabulous predictive tool for financial and social success in the Western world. What would a pseudo-Binet predict for primates? We do not have a clear standard against which we can measure the external validity of such a test. We can critique the ability of the Binet to measure intelligence by finding students with low IQs who achieve good grades in college or locating young adults with high IQs who are unsuccessful in the workplace and in providing for themselves in other ways. But what is the parallel to academic and personal success for a nonhuman primate? When we say that chimps are smarter than, as smart as, or equal to their human counterparts, nothing clearly counts as the falsifying case—both because a nonhuman primate Binet does not exist and because, if one did exist, it would be quite unclear what sort of success it would have to measure in order to measure intelligence. So it is unclear what any of our claims about the comparability of human and nonhuman primate intelligence actually mean.
My third point follows from the second; none of these studies is focused on, or designed to measure, any emotions or cognitive processes that are distinctively nonhuman. While mapping the evolutionary progression and development of cognitive abilities is important, some of the most interesting aspects of evolution are anomalies. The duck-billed platypus gives us wonderful information about flexibility, adaptability, and genetic mutation, even though these creatures are far from human. Likewise, creatures that make different sorts of inferences or sport different types of concepts or practice other forms of species-specific cognition (having nonpropositional content, using context-based thought patterns, etc.) can offer us much information for the overall research project of cognitive ethology. Rather than measure the relative lack of spitefulness in chimpanzees, why not develop new notions of emotional response that are particular to chimpanzee life in the wild and then study it in a controlled setting? Humans, after all, may well get jealous because they very often live in a competitive world of private possessions and exclusive, serially monogamous relationships. Why would we expect to find jealousy in species that live communally and polygamously? (Perhaps, but perhaps not.) And more expansively, in a communal, polygamous society of apes, what emotions might develop with which humans in general might be less familiar? Can traditional Mormon society, with its practices of marrying many wives to one husband, help us reconceive our experimental design? Big Love might inform the typical Western atheist, Christian or Jewish scientist in a surprising way. What nuances of emotion does the third wife feel toward the first and second wives? To the fourth? Such a model could productively inform experiments in several primate societies, and I call for such nuances of emotion to be explored, defined, and developed for experimental use. Better yet, can polygamous primate societies explain Mormon culture, rules, emotions, and mores?9
Moving away from emotions and more toward thought and cognition, I want to raise the question of nonpropositional inferences. Last semester one of my Ph.D. students stated both that primates make inferences and that they do not think. I thought it was a brilliant confusion that reflects the general state of thought in the field. On the one hand, as cognitive ethologists and comparative psychologists, we are intrigued by the potential to discover exactly what types of inferences nonhuman animals make. On the other hand, we make every attempt to stay away from anthopomorphisms such as attributing “thought” or “deduction” to nonhuman animals. We can’t have it both ways. If animals make inferences, then they participate in some form of thought, even though we suspect that they do not think in sentences or make word-based deductions. Fodor (1990) may well be right to say that dogs probably cannot distinguish between thoughts such as “the meat in my dish is good tonight” from “the food in that receptacle in the corner that I usually eat from is delicious.” There is substantial difference in content at a refined level, and dogs are probably unable to discuss those differences. However, they are well able to make inferences about the location of the food and the familiar eating situation (so as to locate that food behind a screen, to actively beg for the food in order to have a door opened for them, or to perform a sequence of tricks in order to have access to food). Since our basic intuition is that animals do make inferences without propositional thought, and since we are highly propositional thinkers, experiments that seek to highlight nonpropositional inferences could reveal the necessary conditions of thought broadly construed and familiarize us with the structure of nonlogocentric inference. Nonpropositional inference patterns will probably still depend on assumptions of object permanence, linear time, and some form of autobiographical memory in the animals tested. But such experiments can be refined to reveal deductions that support the survival and flourishing of the animal rather than explore what we might expect them to be able to do when we have trained them to use a symbol board, human-constructed syntactical patterns, or human labels for objects.
We could begin our science with fewer assumptions of similarities and aim our experiments at discovering differences. We could think about what we actually mean by intelligence and emotional sophistication and define these terms in such a way that they apply across species, rather than using terms designed to describe humans in animal cognition research. We could reconsider the structures of inference and cast them in a way that is nonpropositional. This sort of science would tell us about minds generally, rather than how animal minds relate to human minds, and would stop placing the human mind at the center with the other minds merely in orbit. If thought has a structure, then the lack of propositionality of that structure may be more interesting than seeking how much we can get nonhuman primates to poke at keyboards, gain vocabularies, and work in our propositional world. And from this type of scientific project, a new series of headlines might emerge: headlines about the nature of thought in the animal kingdom or contributing factors for survival for creatures with specific capabilities in specific contexts or new forms of emotion that humans have yet to experience commonly. Rather than react to the dividing line between humans and animals that has been produced by an insecure Western tradition clinging to the (shrinking) specialness of humanity, we can actively seek to explore the nature of mind and intrigue the public with the findings that will emerge from this new paradigm.
In the meantime, we will be confronted with more headlines like this one: “Smarter Than You Think: The Animal Kingdom Is Home to Much Greater Intelligence Than Has Been Previously Acknowledged, with Scientists Seeing Evidence of Human-like Traits Everywhere” (Leake and Warren 2010).
Notes
References
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