Are We Smart Enough to Know How Smart Animals Are?(83)

We have also met a second type of slayer, though, and they have been even harder to deal with since they don’t share an interest in animal behavior. All they care about is humanity’s position in the cosmos, which science has been undercutting since the days of Copernicus. Their struggle has become rather hopeless, though, because if there is one overall trend in our field, it is that the wall between human and animal cognition has begun to resemble a Swiss Gruyère full of holes. Time after time we have demonstrated capacities in animals that were thought to set our species apart. Proponents of human uniqueness face the possibility that they have either grossly overestimated the complexity of what humans do or underestimated the capacities of other species.

Neither possibility is a pleasant thought, because their deeper problem is evolutionary continuity. They can’t stand the notion of humans as modified apes. Like Alfred Russel Wallace, they feel that evolution must have skipped the human head. Although this view is currently on its way out in psychology, which under the sway of neuroscience is edging ever closer to the natural sciences, it is still prevalent in the humanities and most of the social sciences. Typical is a recent reaction by the American anthropologist Jonathan Marks to the overwhelming evidence that animals pick up habits from one another, hence show cultural variability: “Labeling ape behavior as ‘culture’ simply means you have to find another word for what humans do.”3

How much more refreshing was David Hume, the Scottish philosopher who held animals in such high esteem that he wrote that “no truth appears to me more evident than that beasts are endow’d with thought and reason as well as men.” In line with my position throughout this book, Hume summarized his view in the following principle:

’Tis from the resemblance of the external actions of animals to those we ourselves perform, that we judge their internal likewise to resemble ours; and the same principle of reasoning, carry’d one step farther, will make us conclude that since our internal actions resemble each other, the causes, from which they are deriv’d, must also be resembling. When any hypothesis, therefore, is advanc’d to explain a mental operation, which is common to men and beasts, we must apply the same hypothesis to both.4

Formulated in 1739, more than a century before Darwin’s theory saw the light, Hume’s Touchstone offers a perfect starting point for evolutionary cognition. The most parsimonious assumption we can make about behavioral and cognitive similarities between related species is that they reflect shared mental processes. Continuity ought to be the default position for at least all mammals, and perhaps also birds and other vertebrates.

When this view finally gained the upper hand about twenty years ago, supportive evidence poured in from all sides. It was not just the primates anymore but also the canines, corvids, elephants, dolphins, parrots, and so on. The stream of discoveries became unstoppable, featured in the media on a weekly basis to the point that The Onion felt like spoofing the trend in an article claiming that dolphins are not nearly as smart on land as they are in the ocean.5 Joking aside, this was a valid point related to the species-appropriate testing that is one of our field’s main challenges. The public got used to a great variety of claims, including news stories and blogs about animals liberally sprinkled with terms like thinking, sentience, and rational.

Some of it was hype, but many reports presented serious peer-reviewed studies based on years of painstaking research. As a result, evolutionary cognition began to gain standing and attract a growing influx of students ready to cut their teeth on a promising topic. Students like nothing better than a new area where fresh ideas matter. Nowadays many scientists studying animal behavior proudly put the word cognitive in statements about their research, and scientific journals add this trendy term to their names, realizing that it attracts more readers than any other in behavioral biology. The cognitive view has won.

But an assumption is still only an assumption. It doesn’t absolve us from working hard on the issues at hand, which is to determine at what cognitive level a given species operates and how this suits its ecology and lifestyle. What are its cognitive strengths, and how do these relate to survival? It all goes back to the kittiwake story: some species need to recognize their young and others just don’t. The first will pay attention to individual identities, while the second can safely ignore them. Or recall how Garcia’s nauseated rats broke the rules of operant conditioning, as if to drive home the point that remembering toxic food is a magnitude more important than knowing which bar delivers pellets. Animals learn what they need to learn and have specialized ways of sifting through the massive information around them. They actively seek, collect, and store information. They are often incredibly good at one particular task, such as caching and remembering food items or fooling predators, whereas some species are endowed with the brainpower to tackle a wide array of problems.

Cognition may even push physical evolution in a particular direction, such as the reliance of New Caledonian crows on tools crafted out of leaves and twigs. These crows have straighter bills than other corvids and also more forward-facing eyes. The bill shape helps them get a stable grip on their tools, whereas binocular vision lets them peer deeply into the crevices from which they extract caterpillars.6 Cognition is not merely a product of an animal’s senses, anatomy, and brainpower, therefore, but the relation also works the other way around. Physical features adapt to an animal’s cognitive specializations. The human hand may be another example, having evolved its fully opposable thumbs and remarkable versatility to suit our reliance on refined tools, from stone axes to the modern smartphones. This is why evolutionary cognition is such a perfect label for our field, because only evolutionary theory can make sense of survival, ecology, anatomy, and cognition all at once. Instead of searching for a general theory that covers all cognition on the planet, it treats every species as a case study. Of course, some cognitive principles are common to all organisms, but we don’t seek to downplay variation between species with lifestyles, ecologies, and Umwelten as different as, say, a dolphin and a dingo or a macaw and a monkey. Each one faces its own specific cognitive challenges.