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Insects that must travel over long distances before returning home may carry out several of these orientation exercises in order to memorize the sequence of landmarks they should observe on the path to home. Insects use these snapshots by moving about until they are able to match a view of the terrain that they face with a memorized view, almost as if trying to find the right puzzle piece to complete a picture. Collett discovered this behavior by using methods much like those pioneered by Tinbergen. By manipulating the landmarks that surround the target, one can force insects to make predictable errors. For example, by replacing the landmarks seen on orientation flights with other landmarks that look similar but are larger, one can fool insects into thinking that they have arrived home early. This is because the insects misconstrue the larger landmarks as being closer to them than they really are. This is exactly the same principle we use when we judge the size of a building to orient ourselves. The closer we are to it, the larger we expect it to be.
Tinbergen rushed through his doctoral thesis based on the digger wasp experiments because he and his young wife were anxious to set off on a new adventure. Tinbergen had found an opportunity to accompany a small Dutch expedition to Greenland for the International Polar Year in 1933, where he ended up staying for fourteen months living among a small group of isolated Inuit who maintained a largely traditional lifestyle. While Tinbergen’s ostensible role as a biologist was to study several Arctic species, including husky dogs and snow buntings, there is no question that the Inuit community where he lived was a natural match for his careful, observational approach to nature. These people, having survived for thousands of years in forbidding environments, lived by their wits, foresight, and, most important, their keen sense of observation.
There are different regional specializations among Arctic navigators, but the Greenland Inuit, like their Baffin Island cousins, live in regions where there are normally plenty of environmental landmarks, such as the cliffs that form the walls of the steep valleys and fjords. Such landmarks can be seen from great distances and, even when bad weather makes visibility poor, it is usually possible to cling to the valley wall and to keep it in view so as to avoid becoming lost.
A few years ago, on a visit to the community of Clyde River on Baffin Island, I experienced this form of navigation firsthand. On a day trip to explore the stunning beauty and rugged terrain of a nearby fjord, my group traveled over sea ice by snowmobile for about 50 kilometers into a deep valley. When the skies suddenly clouded over and the air filled with the foreboding heaviness of a blizzard, we began a nervous retreat. As the gloom closed in, we lost so much visibility that it was no longer possible to see a horizon or to make any distinction between land and sky. In spite of this, we never lost sight of the difference in color between the rock face on our left and the open ice on our right. Although unnerved that I could see nothing other than the thin contour between brown rock and white ground in my left periphery, I knew we were in no danger of becoming lost provided we maintained visual contact with that dark ridge. I was so used to living in overdetermined visual environments teeming with navigational cues that I clung to my visual lifeline like a child clinging to his mother’s hand.
My sense of danger was considerably heightened by the possibility that, as far out as we were on the sea ice, we might encounter a polar bear. The head of the local Royal Canadian Mounted Police detachment had not helped when, before we set out, he had carefully explained a deep truth for dealing with bears on the ice. With a somewhat concealed twinkle of amusement, he had told me to keep my eyes open and to always remember one thing. “If you’re out on the ice away from your snowmobile and you spot a polar bear, remember the thirty-second rule.”
I bit. “Thirty-second rule? What’s that?”
“In thirty seconds, you’ll be dead.”
When we caught our first glimpse of the village, there was a palpable spirit of celebration. Having come close to a loss of spatial orientation that could have led to a quick death, I had never cherished my sense of place so dearly.
One reason the Inuit are such excellent navigators is that they have an exquisitely tuned ability to pay attention to the visual features of objects and scenes. One oft-cited study, conducted in 1996 by psychologist John Berry, compared the visual abilities of Inuit, modern urban Scots, and the Tenne people, an African agricultural society.4 On a small battery of standard psychological tests of visual function, the Inuit proved equal or superior to the Tenne and Scottish group on all measures. For the Inuit, survival on the land is so dependent on careful visual attention to detail that it is embedded in their language. Inuktitut, one of the languages of the Barren Inuit, contains what have been referred to as obligatory localizers. Just as some languages, such as French or German, require that the gender of nouns be specified and embedded into the syntax of a sentence, Inuktitut requires that the location and orientation of an object be specified as a part of the grammatical structure of a sentence. One example is the three-word Inuktitut sentence “Ililavruk manna ilunga,” which translates as the twenty-word English sentence “Please put this slender thing over there crosswise on that end of that slender thing to which I am pointing.”4 Not only do the Inuit cultivate such sharp observational skills that they possess linguistic specializations obliging them to notice and include spatial references in simple statements about objects but they also use a rich vocabulary to describe the land. Every small feature, hill, or outcropping of rock has a name. The names are woven into stories of events that took place there or describe objects they resemble. The cliff that I followed on my narrow escape from the closing blizzard was called Naujaaraaluit. Nauja is a seagull nest. Raaluk is a size modifier (big seagull nest). Uk changes to uit to denote a place. Naujaaraaluit is the place of the big seagull nests.
By naming landmarks and embedding them into stories, Inuit trekkers are using a tactic analogous to one that is used by digger wasps, but this tactic is much less dependent on geography. The wasps memorize routes using orientation flights in which they simulate their paths to a goal by carrying out the same set of flight movements that they will use later to return to a target. While these movements are taking place, the wasps are recording in memory the appearances of key landmarks. Though skillful Inuit navigators may be just as successful at finding their way home, there has been a key shift in tactics. An Inuit explorer can sit inside by the fire recounting a story to himself and his clan that can have some of the same net effect as the wasp’s orientation flight. This pattern—a human shift from the use of space and geometry to navigate long distances to one based on a mental landscape of words, stories, and ideas—is one that we will see repeated often in the pages to come.
No discussion of Inuit navigation can ignore the prominent built landmarks referred to as inukshuks. These stone sculptures, constructed to resemble human figures, are usually built on high ground with their arms pointing toward shelter. Occasionally, they are used to indicate productive fishing grounds, with their distance from the water’s edge meant to approximate the distance at which fish are to be found. Sometimes strings of inukshuks are built such that peering through a hole in the middle of one can lead to a sighting of another. In addition to their role in navigation, inukshuks can be used as icons to represent departed family members. They can also serve as a kind of hunting aid, like a scarecrow, influencing the direction of movement of caribou herds. Though these structures are certainly used by Inuit for navigation, they have functions that go well beyond those of simple landmarks. Inukshuks are embedded in the cultural fabric of the Inuit.
This is an interesting extension of the human penchant for carrying wayfinding directions in our heads in the form of words and stories. In the case of inukshuks, physical symbols of the stories and legends are placed directly into the picture using carefully balanced piles of rocks. We mark up our environment in ways that adapt it to the mental toolkit we use to find our way through it. In Inuit culture, the connection between land, story, and inukshuk symbol is f
airly straightforward. In modern urban cultures, our uses of landmarks to glue culture and memory to place may be much more dramatic, but the impulses that cause us to create such connections may be universal, with origins in the unique nature of our cognitive makeup.
In recent times, a powerful demonstration of the power of a landmark concerns something that is really the inverse of my experience of watching the growth of the tower in Toronto. On September 11, 2001, the world watched as the World Trade Center in New York City was shattered by the murderous act of a terrorist group. The Twin Towers, initially accepted with great reluctance by New Yorkers, had eventually come to be seen as emblematic of the city’s image, in much the way that their architect, Minoru Yamasaki, had envisioned. Not only could the towers act as an explicit navigational beacon for confused travelers but their iconic value in identifying the skyline of the city was beyond limit. When the towers were destroyed, the response was experienced globally as a combination of disbelief, grief, and, among the local population especially, a yearning for what had been lost so strong that it produced an obsessive tendency to visualize or even reproduce the iconic form of the towers. The most dramatic example of this tendency appears in the annual “Tribute in Light,” in which powerful spotlights shine into the sky from south Manhattan as a reminder of what was lost. To this day, it is almost impossible for the eyes not to be drawn to the former location of the towers as one flies into the city or observes the skyline from across the waters in New Jersey.6 It is a tremendous tribute to the power of the human mind to organize space by attaching it to our stories that the hole left in the landscape by what has been lost can also help to connect us to a place.
HOW WE USE LANDMARKS TO SEARCH FOR WHAT WE’VE LOST
My wife, though she is able to keep track of the locations of all of our children, our social schedule, the birthdate of everyone she has ever met, and all of her secret hiding places for cookies that she doesn’t want me to eat, is utterly incapable of keeping track of her car keys. One of her more notorious episodes of key loss took place in a municipal park with a large grassy playing field. In the middle of a game with the children, she put her keys down in the grass and walked away. At the conclusion of the game, a mad hunt for the small fob of keys in the large field ensued. The experience will be familiar to many. We walked around, trying to recall which particular features of the landscape we had noticed in the area where we had played. Our intuition told us, correctly, that the smaller the distance between such landmarks and the possible location of the keys, the more likely would be our success. If we could only find a way to identify the clumps of grass that we’d been near during our game, it would be much easier for us to find what we had lost. But alas, there were no such easy landmarks, and the keys were never found.
Looking for a lost ring on a beach, gloves forgotten in a shopping center, or a wayward screw in a basement renovation project, we are most likely to take stock of our surroundings and to try to narrow down our search location until all visible landmarks match the orientation and distance that we remember seeing when the lost object was last in our hands. When such strategies fail, it is most often because our memory of the appearances and locations of the landmarks has let us down. We are more likely to succeed when we have carried out a similar search in a similar location on many previous occasions, just as the digger wasp has made many round trips between nest and field to provision the larder for its offspring.
A clever experimenter can ask detailed questions about how we use landmarks in such cases. For example, imagine that, like the digger wasp, you have learned to look for one particular location that is defined by its relationship with a series of closely spaced landmarks. Over the course of thousands of trials, athletes learn to place a hand or foot, throw a ball, or place a stick into a particular location based on its relationship with a set of visible landmarks. What would happen if the relationships among the landmarks themselves were changed? Imagine that your target is always placed in the middle of a square whose corners are marked by four orange pylons. Without your knowledge, a devious experimenter comes along and moves all four of the orange pylons to make the square larger. Suppose that the change is small enough that you fail to notice it. Where do you think you would look for the target?
The answer seems to depend on what kind of animal you are. In experiments that are exactly analogous to the situation I’ve described, some insects and some other animals (rats and gerbils, for instance) will search in a series of four different locations, each related to one landmark, and each one the same distance and direction from that landmark as before the change. It is as if the animal has memorized the exact geometric relationship between each of the landmarks and the target, so it searches four places, each one the predicted target location according to the position of one of the landmarks.
Human beings, on the other hand, continue to search in the center of the square as defined by all four landmarks, even though the distances between them have changed. It is as if the “code” for the location of the target is made up of the relationship between the target and all of the landmarks, rather than any one of them.7
It isn’t completely clear what these differences in behavior might mean, especially since other animals, such as certain birds, also treat landmark arrays in the human fashion. But one possibility is somewhat related to the Inuit tendency to navigate according to named landmarks connected by stories. Suppose that the four orange pylons in our hypothetical experiment were mentally encoded not as a set of four discrete objects but instead as a single shape—a square. We could even imagine that this shape is encoded in our memory not as a very specific collection of corners of a particular size and in a particular location but as something much simpler—like the mental equivalent of the word square.
This kind of encoding would have a couple of advantages. For one thing, it would ease our memory load considerably. But in addition, it would allow us to make predictions about how the shape of the collection of landmarks might look from different points of view without our necessarily being at those viewpoints. Like an Inuit navigator describing the route through a storm-ridden Arctic fjord from the comfort of the fireside, we could describe the location of the target as being at the center of the square. The whole geometric problem is boiled down to, in this case, two simple ideas—center and square. Encoding locations in this highly schematized form, though it has some advantages for memory load and mental portability, also has liabilities. Because such forms jettison geometry, we are prone to make errors when landmarks move around. What if it is the case that one or two of the landmarks we’ve been using have moved? How do we then find our target? In such cases, a rat might have the advantage over us because one of the landmarks could still be used to define the position of the target. For us, on the other hand, if the four landmarks no longer define a nice square, we are left to guess where the center of the square used to be, and any guess would lack precision.
DISTANT LANDMARKS, DIFFERENT RULES
Recently, I visited a colleague in Santa Barbara at one of the campuses of the University of California. I had never been to this campus before, and so my friend sent me directions to his office. The first part of his instructions consisted of a short list of commands to be followed while driving. Provided that I paid attention to the road signs listing highway interchanges and followed the right sequence of left and right turns, I was assured of landing in the correct parking lot at the university. The crucial part of his directions dealt with what happened to me after I left the car. He instructed me to leave the parking garage and then walk so that the mountains were behind me and the ocean was in front of me. In a way, this seems to be entirely in accord with everything we discussed in the last chapter—I was following a simple taxic strategy by using the ocean as an attractive target and the mountains as a repulsive one. In spite of appearances, though, there is a crucial difference. The real target of my movements was not the ocean but my friend’s office. In other words, I was using the moun
tains and the ocean in an entirely different way—these large, obvious, and clearly visible objects were serving as landmarks for a target that, from my starting position, was entirely invisible. Fortunately for me, the man I was meeting was an expert in spatial navigation, so his directions, efficient and precise, guided me to his office with laser accuracy, almost as if I were performing like a small insect on a homing mission.
When I used landmarks to find my colleague’s office in Santa Barbara, I didn’t need to think about the shapes of collections of landmarks at all. I got out of the car, set the mountains behind me and the ocean before me, and I walked. Why are situations such as these so different from those such as looking for lost keys in the grass? In part, because the landmarks involved are very large and very distant. These types of landmarks, sometimes called distal or global landmarks by scientists interested in navigation, behave differently from the clumps of grass or orange pylons that we have been discussing.
Distal landmarks would not work at all to help locate a lost wedding ring on a forest floor, but they can help a monarch butterfly find its way from a summer home in Canada or the United States to overwintering sites in Mexico, or a savvy hiker find her way out of a dense forest and to the nearest highway. Landmarks like the sun, moon, distant mountain ranges, or even skyscrapers or cityscapes enjoy special status among the tools used by navigators both human and otherwise because they have an ideal collection of properties that can assist wayfinders. If they are both very distant and visible, then they are also probably very large and therefore immobile. Large, immobile objects can be relied upon to stay where they are, and so define locations and directions. (The sun, moon, and stars are exceptions. Such objects change position as the earth rotates, but because such movements are predictable, we can learn their patterns and use these objects as landmarks anyway.) The other kind of landmark—pinecones near a wasp nest, clumps of grass, or bits of rock in a meadow—are not nearly as reliable. They might remain in place, or they might be kicked away, eaten, or even disturbed by curious scientists.