Mind in Motion

by Barbara Tversky

  We think about time as movement on a line in space. “We’re marching through time.” But there’s also “Time marches on.” Which is it? What’s moving, time or us? Are we moving through time, the way we move through space? Or is time moving past us? Are we sitting in place, like a king on a throne, with events coming to us, like subjects in the kingdom? Or are we moving through a crowd, like a politician before an election, hugging babies one after another? We face the future—it is in front of us (in English, but not in at least one other language). Do we boldly walk forward or do the events approach us? Actually, both, and there’s the confusion. Consider the Famous Ambiguous Question asked in many experiments: someone tells you that next Wednesday’s meeting has been moved forward two days. When is it? Half answer Friday—I am moving toward the meeting time; half answer Monday—the meeting time is moving toward me.

  These two metaphors for thinking about time have been called moving ego and moving time. For We’ve moved past the worst; the best is yet to come, the first clause uses moving ego and the second, moving time. Did you notice that switch the first time you read the sentence? In both, you are embedded firmly in the middle of the time line, you are facing forward in the deictic center separating the past from the future. The future is in front of you; the past is behind. Both moving ego and moving time take egocentric perspectives on time.

  Answers to the Famous Ambiguous Question depend on what’s moving, you or things in the world. If you are moving or have just moved, you are likely to be biased toward the moving ego metaphor and answer Friday. If you are stationary and watching something else move toward you or away, you are likely to be biased toward the moving time metaphor and answer Monday. Movement in space biases thought about time, but not the other way. More generally and central to the Sixth Law of Cognition: Spatial thinking is the foundation of abstract thought, thought about space biases thought about time, but not vice versa. Space, moving in it or watching motion, is the foundation. The rest follows. A highly significant consequence of the mapping of time to space is order. With our eyes, we can see that places are ordered in space; it is our movement from place to place that orders events in time. We cannot see events in time; ordering events in time is conceptual, the mind does it. Same for ordering by quantity or preference or power.

  Both ways, either way, one common way we talk about events in time is as though they were landmarks on a line in space, a space we move through or one that moves past us. Both metaphors, moving ego and moving time, place us inside, on the time line, just as route perspectives place us inside space. The path through time is lined with events just as the path through space is lined with landmarks. But in our minds and in our talk, we can get out of time and above it, just as we can get out of space and above it.

  Allocentric perspective on time

  Not every statement about time is ambiguous, just as not every statement about space is ambiguous. Outsider perspectives can reduce ambiguity. Let’s meet at the NW corner of Broadway and 42nd at 7:45 p.m. (yes, there’s still ambiguity; we didn’t specify where on the NW corner, nor did we specify the second). Just as there’s an outside perspective on space, there’s an outside perspective on time, an egoless, allocentric perspective. Another analogy from space to time. We can call it a calendar perspective. Or an absolute perspective. It can come with dates, hours, minutes just as space can come with names of locations or GPS coordinates. A calendar gives an overview of a swath of time just as a survey perspective gives us an overview of a swath of space. There’s no ambiguity about which day in the calendar view: we simply move Wednesday’s meeting to Friday. Or to Monday.

  Instead of a single line—a route—through space or a single line through time, an egoless overview gives many possible routes through space or lines through time. We can schedule lunches every Tuesday at noon and classes Monday, Wednesday, and Friday at three. That egoless calendar perspective on time surfaces in many places. In novels, newspaper reports, history books, in time lines on museum walls and in textbooks. One event after another, viewed from outside, not from a specific temporal perspective inside. Think of graphs of some variable like population or GNP changing over time; think of musical scores. Now think of the gestures we make or observe as someone relates events in time, a story or a procedure for doing something. Slices of the hand moving along a line, each slice a new event, viewed from the outside, the ego looking on.

  Distortions

  Because thought about time is based in thought about space, it should not be surprising that many of the distortions and biases we saw for space hold for time. There are landmarks in time just as there are landmarks in space, and ordinary events are judged as closer to temporal landmarks than they actually are, just as ordinary buildings in space are judged as closer to landmarks in space than they actually are. Remember Pierre’s house and the Eiffel Tower? College students tend to remember events like going to the movies or exams as closer to the beginnings or ends of semesters than they actually were. Events in time get telescoped, just like places in space. Events in the distant past are judged relatively closer together in time, and more recent events are judged relatively farther apart.

  But, alas, like most analogies, the analogy from space to time runs into trouble. Unlike space, time as we know it is unidirectional. Many’s the time that we wish we could go backward in time, to revisit the good times or revise the bad ones, the same way we can go back in space to revisit the good places and maybe even revise the bad ones.

  Cycles: Circular time?

  Many of you are undoubtedly balking at this point. What about seasons, cycles? What about other cultures? Think of clocks. We thought similarly. So, we asked dozens of people to think about a familiar repeating process, cyclical events like the seasons, washing clothes, the events of a day, or seed to flower. We then asked them to represent each on a page. We got many adorable diagrams with whimsical depictions (so much for least effort), but the vast majority were lines, not circles. We next pushed hard, giving events that began and ended with the same event, say seed-to-flower-to-seed, and listing the events in columns rather than rows. Even so, linear diagrams always outnumbered circular ones. For those of you who believe that Asian cultures think about time circularly, we collected data in China. Chinese participants responded the same as Americans, overwhelmingly creating linear representations of cyclical events.

  Okay, ordinary people (and extraordinary people as well) aren’t inclined to spontaneously use circles to represent cyclical events—but do they understand them? After all, cyclical events are so often depicted as circles in newspapers and textbooks. We asked large numbers of people to interpret a variety of circular diagrams of cyclical events, scientific, like the rock cycle and cell division, and everyday cycles, like the seasons and washing clothes. Fortunately, they had no trouble interpreting circular diagrams; they simply didn’t spontaneously produce them. They could even fill in templates of circles with cyclical events like seed to flower or cell division or the seasons. But those circles weren’t never-ending, with no beginning and no end. On the contrary, they had beginnings and ends; they began at twelve o’clock and proceeded clockwise.

  After many attempts, we finally succeeded in getting a majority of participants to create circular representations of time. Perhaps you remember that from Chapter Five. The trick was gesture. We sat with them and explained the events using a circular gesture, putting the first stage at twelve o’clock, the second at three, the third at six, and the last at nine. Then we gave them a piece of paper and asked them to put something on the page to represent the events. In that case, a majority of people made circular diagrams. Interestingly, that set of gestures not only changed their diagrams but also changed their understanding. In a follow-up study, we explained the sequence of events, the seed to flower, with circular gestures for half our participants and with linear gestures for the other half. Then we asked, “What comes next?” Those who had viewed circular gestures went back to the beginning. They said th
ings like, “A new seed is formed.” Those who had viewed linear gestures continued to a different event. They said things like, “I gather the flowers for a bouquet for my girlfriend.” Gestures changed their thought!

  It was a struggle to get people to produce circular representations of familiar cyclical events, like the seasons and doing laundry. When you think about it, circular diagrams of cyclical processes defy time. Time doesn’t go back on itself. Nor does the process. The seed that generated the flower isn’t the same seed that the new flower forms. Each winter is a new winter. Perhaps even deeper, we think about processes in time as having beginnings, middles, and ends—outcomes. You start somewhere and end somewhere else, with something different. A journey. An explanation. A story. A process that creates a product. Circles are never-ending—they have no beginning and no end.

  That linear bias, the strong tendency to see and explain events as unfolding in time, as linear processes with beginnings, middles, and ends that are outcomes, has dominated the conduct of life, including the conduct of science. But that linear bias has also impeded progress in science. Remember the First Law of Cognition: There are no benefits without costs. One enormously important phenomenon that is not linear and that appears across the sciences is self-regulation, processes that oscillate to support a steady state, typically represented by circles. For self-regulation, the circles are true to geometric circles; they have no beginning and no end. Self-regulatory systems are crucial in biology under the rubric homeostasis. Homeostasis wasn’t recognized until the late nineteenth century by Claude Bernard and only popularized by Cannon half a century later.

  A familiar example of homeostasis is the maintenance of body temperature: when it gets too high, processes set in to lower it, and when it gets too low, other processes set in to raise it. A thermostat is similar but simpler: sensors that detect room temperature send messages to turn up the heat when the temperature gets below the set point or to turn on the AC when the temperature gets above the set point.

  Representations of brains as well as computers are still dominated by linear conceptualizations. For the nervous system, sensory input central processing motor output. For computers, input throughput output. Yet feedback, also self-regulatory, is as fundamental to the workings of the brain as it is to computer systems. So strong was the input-throughput-output model of the brain that only after years of studying the feedforward pathways from sensory areas to central areas of the brain and from central areas to motor ones did neuroscientists notice that there are as many feedback pathways as feedforward pathways. This discovery has opened exciting new research: How does feedback modulate feedforward? And feedforward feedback? It feels a bit like defying time. After all, this is circular. Or perhaps a spiral. Either way, the change of perspective, from linear to circular, enabled new discoveries. Biases can impede perception and certainly discovery. Change of perspective like this underlies many leaps of creativity. More on that in Chapter Nine.

  Directionality

  Back to barebones time. We’ve seen that for the most part, people think of events in time as linked one after another on a line. But which way does the line go? Vertical or horizontal? If horizontal, does it go sagittally, sideways, across the body, or coronally, through the body, in front or back of the body? The answer seems to be all three, depending. Depending on whether we’re talking or drawing or gesturing. Depending on the language we speak. Whatever the direction, the time line never goes diagonally and, as we have seen, only rarely circularly. Lines like stability, either supported horizontally or balanced vertically. Now a closer look.

  Talk about time: Is the future in front or behind?

  In English and many other languages, the future is in front of us whether we are moving forward or events are moving toward us. The past is behind us. Motion in space is key to putting the future in front. We are facing forward whether we are moving past events or we are greeting events moving toward us. Now is in the middle of the time line, like here in space. For at least one other language, notably Aymara, an Amerindian language spoken in the Andes in South America, perception of space rather than action in it is key to talk and thought about time. The horizontal plane representing events in time goes the opposite direction. The past lies in front because it can be seen; the future is behind because it cannot be seen. Whether this is a curiosity of a single language or more general remains to be seen.

  Talk about time: The future is down. Calendars and some spontaneous sketches of time use the vertical dimension, with earlier events higher and later events lower. There is no “now,” no deictic center in a calendar. In speech, Mandarin uses the vertical plane in addition to the horizontal plane. Earlier events are sometimes spoken of as up and later events spoken of as down.

  On the page and in the air. Hundreds of kids and adults were asked to put stickers or marks on a page to represent the times for breakfast, lunch, and dinner. Most, even the preschoolers, ordered the meals of the day on a line, a horizontal one, but the starting point depended on reading and writing habits. Those who spoke a language written left to right, namely, English, lined up the events left to right, starting with breakfast. Those who spoke a language written right to left, namely, Arabic, lined up the events right to left, starting with breakfast. A sizable minority of the Arabic speakers used the vertical, as in a calendar, with earlier events higher and later ones lower. Intriguingly, speakers of Hebrew went fifty-fifty. Like Arabic, Hebrew is written right-to-left, but unlike Arabic, numbers increase left to right, as in Western languages.

  Now to gesture, in the air. When describing events in time, speakers of languages written left to right do the same, their gestures line up the events horizontally across the body starting from the left. Interestingly, speakers’ gestures go left to right from their point of view, so listeners see them as right to left. This is a general phenomenon for gesture: speakers gesture from their own points of view. We saw in the last chapter that in spoken languages, speakers frequently assume the perspective of listeners. However, in signed languages, speakers take their own perspective; speaker perspective is embedded in the syntax, so listeners often need to flip the direction.

  Again, something that seemed simple has gotten complicated. Space has two (or three) dimensions, time has only one—why is time so complicated? There is a bottom line, and it is indeed a line: people order events in time on a line in talk, gesture, and graphics. Which way the line goes is where it gets complicated. For most cases, the line is horizontal and sideways. The preference for sideways in gesture and graphics is likely to be pragmatic; sideways is easier to see, both on the page and face-to-face. The order, from left to right or right to left, seems driven by a cultural artifact, reading and writing order. The front-back plane is used in talk but rarely in graphics; most languages seem to put the future in front, the direction of movement, but at least one puts the past in front, the direction of perception. The vertical dimension shows up frequently in graphics, notably calendars, and some in talk, in Mandarin and perhaps other languages. Time is a neutral dimension, in contrast to quantity, value, and preference. As we will soon see, neutral dimensions tend to land on the horizontal and dimensions with value tend to favor the vertical. The latter seems to have something to do with countering gravity. Countering gravity takes strength, power, health, wealth—all things that have value.

  Ordering events on a time line entails abstraction; it means ignoring everything else about the events except their order in time. At the same time, ordering events by time makes order, in one’s life, in the lives of others, in science, in politics, and in history. Ordering by time or any attribute allows comparisons and inferences. Importantly, what event precedes another. Roughly how far apart in time pairs of events are from each other; the more intervening events, the farther. This is a qualitative judgment, not a quantitative calculation. Which event preceded or followed another. Ordering allows transitive inference: if A came before B and B before C, then A came before C. Knowing which event ca
me before another underlies inferences about causality. Except for some arcane theories of physics, causes precede effects. Ordering events in time is a fundamental first step to understanding causality. Without an appreciation of causality, we would not reach for a glass or lift our legs one after another to climb stairs. We would not try to catch a falling object or turn a door handle. Understanding causality is crucial to understanding ourselves and others and everything else that happens or happened or might happen.

  ORDERS: WHO’S ON TOP?

  Quantity, preference, value—anything that can be ordered on a dimension

  The worst time to rob a house and the best time to go out to eat is during the Oscars, the Super Bowl, the World Cup finals. People are obsessed with ordering: who’s the best singer, actor, football player? Who’s the wealthiest? The strongest? What’s the best film, TV show, restaurant, wine, guacamole recipe, cell phone, car? Among chimps (and other species), who’s the alpha male? Orders have enormous implications and enormous power. The alpha male gets the best pickings, ensuring his continued dominance. Prizewinning books, computer games, and movies can make fortunes. The runners-up, second-bests, also-rans—alas, soon forgotten. Reducing a set of people, places, or things to a single order leads to fascinating discussions or endless arguments. Ordering seems embedded in our biology, certainly in the biology of our ancestors: pecking orders, dominance orders. And it is certainly built in to our lives: elections, the World Series, the Olympics, contests that grip nations for weeks.