Did we have to go through this bleak period? In earlier days, the thinking was noticeably more liberal. Charles Darwin wrote extensively about human and animal emotions, and many a scientist in the nineteenth century was eager to find higher intelligence in animals. It remains a mystery why these efforts were temporarily suspended, and why we voluntarily hung a millstone around the neck of biology—which is how the great evolutionist Ernst Mayr characterized the Cartesian view of animals as dumb automatons.2 But times are changing. Everyone must have noticed the avalanche of knowledge emerging over the last few decades, diffused rapidly over the Internet. Almost every week there is a new finding regarding sophisticated animal cognition, often with compelling videos to back it up. We hear that rats may regret their own decisions, that crows manufacture tools, that octopuses recognize human faces, and that special neurons allow monkeys to learn from each other’s mistakes. We speak openly about culture in animals and about their empathy and friendships. Nothing is off limits anymore, not even the rationality that was once considered humanity’s trademark.
In all this, we love to compare and contrast animal and human intelligence, taking ourselves as the touchstone. It is good to realize, though, that this is an outdated way of putting it. The comparison is not between humans and animals but between one animal species—ours—and a vast array of others. Even though most of the time I will adopt the “animal” shorthand for the latter, it is undeniable that humans are animals. We’re not comparing two separate categories of intelligence, therefore, but rather are considering variation within a single one. I look at human cognition as a variety of animal cognition. It is not even clear how special ours is relative to a cognition distributed over eight independently moving arms, each with its own neural supply, or one that enables a flying organism to catch mobile prey by picking up the echoes of its own shrieks.
We obviously attach immense importance to abstract thought and language (a penchant that I am not about to mock while writing a book!), but in the larger scheme of things this is only one way to face the problem of survival. In sheer numbers and biomass, ants and termites may have done a better job than we have, focusing on tight coordination among colony members rather than individual thought. Each society operates like a self-organized mind, albeit one pitter-pattering around on thousands of little feet. There are many ways to process, organize, and spread information, and it is only recently that science has become open-minded enough to treat all these different methods with wonder and amazement rather than dismissal and denial.
So, yes, we are smart enough to appreciate other species, but it has required the steady hammering of our thick skulls with hundreds of facts that were initially poo-pooed by science. How and why we became less anthropocentric and prejudiced is worth reflecting on while considering all that we have learned in the meantime. In going over these developments, I will inevitably inject my own view, which emphasizes evolutionary continuity at the expense of traditional dualisms. Dualisms between body and mind, human and animal, or reason and emotion may sound useful, but they seriously distract from the larger picture. Trained as a biologist and ethologist, I have little patience with the paralyzing skepticism of the past. I doubt that it was worth the oceans of ink that we, myself included, have spent on it.
In writing this book, I do not seek to provide a comprehensive and systematic overview of the field of evolutionary cognition. Readers may find such reviews in other, more technical books.3 Instead, I will pick and choose from among many discoveries, species, and scientists, so as to convey the excitement of the past twenty years. My own specialty is primate behavior and cognition, an area that has greatly affected others as it has been at the forefront of discovery. Having been part of this field since the 1970s, I have known many of the players firsthand—human as well as animal—which allows me to add a personal touch. There is plenty of history to dwell on. The growth of this field has been an adventure—some would say, a roller-coaster ride—but it remains endlessly fascinating, since behavior is, as the Austrian ethologist Konrad Lorenz put it, the liveliest aspect of all that lives.
1 MAGIC WELLS
What we observe is not nature in itself, but nature exposed to our method of questioning.
—Werner Heisenberg (1958)1
On Becoming a Bug
Opening his eyes, Gregor Samsa woke up inside the body of an unspecified animal. Equipped with a hard exoskeleton, the “horrible vermin” hid under the sofa, crawled up and down walls and ceilings, and loved rotten food. Poor Gregor’s transformation inconvenienced and disgusted his family to the point that his death came as a relief.
Franz Kafka’s Metamorphosis, published in 1915, was an odd opening salvo for a less anthropocentric century. Having selected a repulsive creature for metaphorical effect, the author forced us from the very first page to imagine what it is like to be a bug. At around the same time, Jakob von Uexküll, a German biologist, drew attention to the animal point of view, calling it its Umwelt. To illustrate this new concept (German for the “surrounding world”), Uexküll took us on a stroll through various worlds. Each organism senses the environment in its own way, he said. The eyeless tick climbs onto a grass stem to await the smell of butyric acid emanating from mammalian skin. Since experiments have shown that this arachnid can go for eighteen years without food, the tick has ample time to meet a mammal, drop onto her victim, and gorge herself on warm blood. Afterward she is ready to lay her eggs and die. Can we understand the tick’s Umwelt? It seems incredibly impoverished compared to ours, but Uexküll saw its simplicity as a strength: her goal is well defined, and she encounters few distractions.
Uexküll reviewed other examples, showing that a single environment offers hundreds of realities peculiar to each species. Umwelt is quite different from the notion of ecological niche, which concerns the habitat that an organism needs for survival. Instead, Umwelt stresses an organism’s self-centered, subjective world, which represents only a small tranche of all available worlds. According to Uexküll, the various tranches are “not comprehended and never discernible” to all the species that construct them.2 Some animals perceive ultraviolet light, for example, while others live in a world of smells or, like the star-nosed mole, feel their way around underground. Some sit on the branches of an oak, and others live underneath its bark, while a fox family digs a lair among its roots. Each perceives the same tree differently.