On Trails (11 page)

A few years ago, my partner and I moved from a small apartment in New York City to a small cabin in British Columbia. Behind our property stands a tall cedar forest, and behind that lie the cold green waters of the Georgia Strait. The cabin often startles visitors when they first see it. Our next-door neighbor, Johnny, a classical guitarist, built it in a fit of modernist whimsy; it looks like two railroad cars stacked one atop the other. The ground floor is made of polished concrete, and the windows are almost the size of the walls. The insulation is scant, the electricity is always cutting out, the garden is plagued with deer, and the nearest supermarket is a twenty-five-minute drive away, but it's quiet and the air is clean and there are plenty of walking trails nearby.

At the end of our dirt road, where it joins a bend in the main thoroughfare like a needle in the crook of an arm, there is a little trail leading off into the woods. Johnny informed us that it led to a place the locals call the Grassy Knoll: a soft green tuft atop a rock outcropping over the strait. It's a lovely perch, they say, to watch the sun set over the mountains of Vancouver Island. However, Johnny strongly advised us against staying that long, for fear we might get lost. “Even I get turned around in there,” he said, “and I've lived here for twenty years.” Another neighbor, Corey, told us that he'd once gotten lost while walking in the forest with his infant daughter. When the sun began to set, he felt the first electric touch of panic, an early sign of what psychologists call “woods shock,” or what used to be called simply “bewilderment.” He kept his wits and got out, but as he recounted the story one night around a campfire, I could see the feeling seep up, blackly, behind his eyes.

Remi and I were not worried. It was just a little provincial park, after all, only five hundred acres. If lost, one need only walk three miles in any direction to hit either the coast or a road. Setting off at about three o'clock, we walked down to the end of our street and ducked through the dark curtain of branches.

On the other side, the light clouded to the opacity of sea glass. We looked around, blinking, at a temple of riotous decay, evergreen, shade-blue. On the coasts of British Columbia, the prodigious rainfall, sunny summers, and rich soil thrust the trees upward; the taller ones shed their lower branches like the vestigia of a rocket ship. But eventually that which nourishes, topples. The trees fall to the ground quietly, with a huff, and there turn to moist brown crumbs. Everything, everywhere, is furred with moss and bearded with lichen. Slip on a wet root and you will fall, weirdly slowly, through the gray-green air, and the ground will rise up to receive you in its soft heft.

The trail wasn't built by the park service—some local do-gooders had apparently cleared it—which meant that it was less legible than it might otherwise be. The only trail markings were the occasional ribbon tied to a branch where the trail skirted a swamp. The paths tended to split and splice. Johnny had given us directions for finding the knoll: turn right at the first T-shaped fork in the path and keep left until you reach the shore. It seemed simple enough.

When we reached the first fork in the trail, Remi propped a stick up against a tree so we would have a point of reference in case we got lost. We turned right and followed the trail around in a wide arc, chatting happily, until we found ourselves standing at a fork in the path. There, off to the side, was the stick Remi had propped up against the tree. We had gone in a circle. Befuddled, we turned around and set off in the opposite direction this time, and, minutes later, found ourselves back at the stick again.

In
Roughing It
,
Mark Twain recalls heading out into a snowstorm, bound for Carson City. A man named Ollendorff, bragging that his instinct was as sure as any compass, promised to lead the group. After half an hour of plodding through the snow on horseback, the men came upon fresh hoof-tracks in the snow. “I knew I was as dead certain as a compass, boys!” shouted Ollendorff. “Here we are, right in somebody's tracks that will hunt the way for us without any trouble.”

The men began to trot along the tracks. Before long it became evident that they were gaining on whoever was up ahead, because the tracks grew more distinct.

We hurried along, and at the end of an hour the tracks looked still newer and fresher—but what surprised us was that the
number
of travelers in advance of us seemed to steadily increase. We wondered how so large a party came to be traveling at such a time and in such a solitude. Somebody suggested that it must be a company of soldiers from the fort, and so we accepted that solution and jogged along a little faster still, for they could not be far off now. But the tracks still multiplied, and we began to think the platoon of soldiers was miraculously expanding into a regiment—Ballou said they had already increased to five hundred! Presently he stopped his horse and said:

“Boys, these are our own tracks, and we've actually been circussing round and round in a circle for more than two hours out here in this blind desert!”

It has been thought for centuries that human beings have a natural tendency to walk in circles. In 1928, a biologist named Asa Schaeffer claimed to have shown experimentally that blindfolded people walk, run, swim, row, and drive automobiles in spiraling patterns, a phenomenon he attributed to a “spiral mechanism” in the brain. The navigator Harold Gatty believed that people circled because of simple biological asymmetry; one leg tends to be longer or stronger than the other. (“With regard to our anatomy,” he wrote, “we are all of us unbalanced.”) In 1896, the Norwegian biologist F. O. Guldberg argued that circling was one of the “general laws” of biology. He recounted stories of birds wheeling in front of lighthouses, schools of fish whirling in the lamps of deep-sea divers, hares
and foxes circling to escape hunters, and men lost in fog wandering in loops.

Guldberg didn't see circling as a form of error. The law of circular movement, he argued, assures that lost animals will always be able to find their way back to “the native place to which animals in the struggle for existence must so often return, be it the udder of the cow, the warmth-giving wings and the guiding experience of the hen, or the sheltering tree or bush chosen by maternal instinct.” Whether we like it or not, he argued, we circle to find our way back to familiar ground.

In 2009, a researcher named Jan Souman decided to test the circling instinct. He equipped volunteers with GPS tracking devices and instructed them to walk in a straight line across unfamiliar terrain, both in the forests of Germany and the deserts of Tunisia. Without the aid of directional cues, like the sun, the subjects did tend to circle back on their own trails; that much is true. “It seems easy to walk in a straight line,” Souman told me. “But if you think about it, it's actually not that easy at all.” Like riding a bicycle, walking a straight line is in fact a complex neural balancing act, which is what makes it an effective test of whether a person has had too much to drink.

Further experiments ruled out leg length and leg strength as factors. Souman also found no evidence to support the assumption that there is a “circling instinct” in the brain. The paths his subjects took were not big circles or spirals, but rather something more like the random squiggles a toddler makes with a crayon. At times, they looped back on themselves—the point at which walkers typically spot a familiar landmark, falsely conclude that they are
walking in a circle
,
and begin to panic—but walkers almost never circled all the way back to the start. Souman concluded that on average people who are lost, without external navigational cues, will typically not travel farther than one hundred meters from their starting point, regardless of how long they walk.

A horrifying thought: On a cloudy day, in tall woods, with no other cues and no compass, a person will not travel more than the length of a football field in any one direction.

Remi and I were in just such a situation. The sky was dull pewter. Everything was covered equally in moss, so that old trick wouldn't be of any help. We hadn't brought a compass, as Johnny had advised. I did have my phone, which had a digital compass, but the one time I ever needed it, the needle spun limply, like a wandering eye. We were cut off from every form of external reference, except the trail. At one point we grew so frustrated in our circling that we struck off, bushwhacking in the direction we guessed the water must be, but we soon became nervous about getting lost, so we dutifully returned to the charmed thread.

At last, as the sky was darkening, one of us realized there were in fact two forks in the trail that looked identical, because some other hiker had previously propped up another stick against a tree in precisely the same fashion we had. Remi kicked the stick into the woods and the spell was broken. The next turn at the fork took us directly home.

+

According to Guldberg, Norwegian country folk refer to the act of walking in circles as “approaching on a false scent.” The phrase—which must be somewhat rare, because the Norwegians I've spoken to have never heard it—wonderfully evokes the illusory sense of progress that attends the circling walker. Circular arguments function in much the same way: One side feels that an intellectual victory is just within reach, as does the other side. Both sides launch attacks and counterattacks and counter-counterattacks, but neither can win a decisive victory, and so the two continue “circussing round and round,” like a pair of rats chasing one another around the outer rim of a barrel.

Until the latter half of the last century, ant researchers generally fell into one of two camps: they either believed ants were sentient beings, capable of learning, or they believed they were instinctive machines. As explanations based on God's role as a “prime mover” fell out of fashion in the nineteenth century and evidence of ants' problem-solving abilities continued to mount, the proponents of sentience appeared to be gaining ground. But then, beginning in the 1930s, Konrad Lorenz, the father of a new field of science called ethology, injected new life into the mechanistic argument by showing how insects rely upon “fixed action patterns”—what, in a prior era, would have simply been called “instincts”—which were genetically
coded
,
rather than divinely ordained. God was swapped out, and genetics was swapped in, but the basic argument remained the same. At its heart, the debate revolved around a central paradox: If ants are intelligent, then why do individual ants behave so stupidly? But then, if ants are empty-headed, how can their colonies solve such a wide array of complex problems so brilliantly?

It was not until the advent of computing that this circle was finally broken; early computers opened up a new path forward. By programming computers to perform insect-like tasks, and by studying the (previously, overwhelmingly complex) behavior of swarms using computers, we began to understand that simple
machines following a simple set of rules can ultimately make highly intelligent decisions. They are not
either
simple
or
smart; they're
both
.

Regular conferences in the new field of “cybernetics”—the study of automated systems—were held throughout the late 1940s and early 1950s, where biologists and computer scientists began discussing the considerable overlap between their fields. At the second meeting, Schneirla gave a lecture on how he had trained a common black ant to navigate a maze—being careful to regularly swap out the paper linings on the floor, so that trails couldn't accumulate—which proved that some ants could memorize basic routes. This finding
suggested that individual ants had more powerful brains than many scientists had previously suggested. However, this proposition was later undercut when another attendee, Claude Shannon—famous for quantifying information into “bits”—successfully built a robotic ant, with a processor that was ten times simpler than even the most rudimentary pocket calculator. An electronic “antenna” on wheels, the robo-ant explored mazes following a simple trial-and-error program, bumping up against the walls until the antenna touched its “goal” (a button that shut off the robot's motor). On the second run-through, having memorized the maze, the robo-ant was able to complete it without touching any of the walls.

The roboticization of the insect world has continued steadily ever since. A few years ago, a researcher named Simon Garnier built robotic ants that could follow electronic pheromone trails. The trails were laid down by a row of overhead projectors, which automatically tracked each robo-ant's movement; meanwhile, light sensors were installed in each robo-ant's “head,” so it could follow the other robo-ants' glowing trails. Essentially, by following just two simple rules—explore randomly until you find either a “trail” or “food,” and follow the strongest trail you find—the robo-ants were ultimately able to find the shortest route through a maze.

The shift toward studying ant colonies as robotic rule-followers was mirrored by a growing sense that an ant colony could function as a single, self-organizing system, much as a computer is a collection of individual circuits. This idea was famously demonstrated in the 1970s by a Belgian researcher named Jean-Louis Deneubourg. One of his most famous experiments involved connecting a nest of Argentine ants and a food source with two different bridges. The two bridges were alike in all respects, except that one bridge was twice as long as the other. In the beginning, the ants chose between the two bridges randomly, but over time, the colony overwhelmingly chose the shorter bridge, for the simple fact that their pheromones
accumulated there more quickly. The ants' system was neatly self-­regulating—the shorter the path, the fresher the pheromones, and the more traffic it attracts. Here was the key: Ants may be individually stupid, but they have a high level of what Deneubourg calls “collective intelligence.”