The Great Mental Models Read online

  As a rational being, each herdsman seeks to maximize his gain. Explicitly or implicitly, more or less consciously, he asks, “What is the utility to me of adding one more animal to my herd?” This utility has one negative and one positive component.

  The positive component is a function of the increment of one animal. Since the herdsman receives all the proceeds from the sale of the additional animal, the positive utility is nearly +1.

  The negative component is a function of the additional overgrazing created by one more animal. Since, however, the effects of overgrazing are shared by all the herdsmen, the negative utility for any particular decision-making herdsman is only a fraction of 1.

  Adding together the component partial utilities, the rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another; and another. . . . But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein is the tragedy. Each man is locked into a system that compels him to increase his herd without limit—in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons. Freedom in a commons brings ruin to all.” 3

  What is common to many is taken least care of, for all men have greater regard for what is their own than for what they possess in common with others. –Aristotle

  Here’s another way to think about it. Economist Elinor Ostrom wrote about being cautious with maps and models when looking at different governance structures for common resources. She was worried that the Tragedy of the Commons model (see sidebar), which shows how a shared resource can become destroyed through bad incentives, was too general and did not account for how people, in reality, solved the problem. She explained the limitations of using models to guide public policy, namely that they often become metaphors.

  “What makes these models so dangerous … is that the constraints that are assumed to be fixed for the purpose of analysis are taken on faith as being fixed in empirical setting.”4

  This is a double problem. First, having a general map, we may assume that if a territory matches the map in a couple of respects it matches the map in all respects. Second, we may think adherence to the map is more important than taking in new information about a territory. Ostrom asserts that one of the main values of using models as maps in public policy discussions is in the thinking that is generated. They are tools for exploration, not doctrines to force conformity. They are guidebooks, not laws.

  «Remember that all models are wrong; the practical question is how wrong do they have to be to not be useful.»

  George Box5

  In order to use a map or model as accurately as possible, we should take three important considerations into account:

  Reality is the ultimate update.

  Consider the cartographer.

  Maps can influence territories.

  Reality is the ultimate update: When we enter new and unfamiliar territory it’s nice to have a map on hand. Everything from travelling to a new city, to becoming a parent for the first time has maps that we can use to improve our ability to navigate the terrain. But territories change, sometimes faster than the maps and models that describe them. We can and should update them based on our own experiences in the territory. That’s how good maps are built: feedback loops created by explorers.

  We can think of stereotypes as maps. Sometimes they are useful—we have to process large amounts of information every day, and simplified chunks such as stereotypes can help us sort through this information with efficiency. The danger is when, like with all maps, we forget the territory is more complex. That people have far more territory than a stereotype can represent.

  In the early 1900s, Europeans were snapping pictures all over Palestine, leaving a record that may have reflected their ethnographic perspective, but did not cover Karimeh Abbud’s perception of her culture. She began to take photos of those around her, becoming the first female Arab to set up her own photo studio in Palestine. Her pictures reflected a different take on the territory—she rejected the European style and aimed to capture the middle class as they were. She tried to let her camera record the territory as she saw it versus manipulating the images to follow a narrative.

  Her informal style and desire to photograph the variety around her, from landscapes to intimate portraits, have left a legacy far beyond the photos themselves.6,7 She contributed a different perspective, a new map, with which to explore the history of the territory of Palestine.

  We do have to remember though, that a map captures a territory at a moment in time. Just because it might have done a good job at depicting what was, there is no guarantee that it depicts what is there now or what will be there in the future. The faster the rate of change in the territory, the harder it will be for a map to keep up to date.

  _

  Dividing a large chunk of the Middle East into simply A and B, the Sykes-Picot line proposed borders that paid little regard to ethnic or geographical features.

  «Viewed in its development through time, the map details the changing thought of the human race, and few works seem to be such an excellent indicator of culture and civilization.»

  Norman J.W. Thrower8

  Consider the cartographer: Maps are not purely objective creations. They reflect the values, standards, and limitations of their creators. We can see this in the changing national boundaries that make up our world maps. Countries come and go depending on shifting political and cultural sensibilities. When we look at the world map we have today, we tend to associate societies with nations, assuming that the borders reflect a common identity shared by everyone contained within them.

  However, as historian Margaret MacMillan has pointed out, nationalism is a very modern construct, and in some sense has developed with, not in advance of, the maps that set out the shape of countries.9 We then should not assume that our literal maps depict an objective view of the geographical territory. For example, historians have shown that the modern borders of Syria, Jordan, and Iraq reflect British and French determination to maintain influence in the Middle East after World War I.10 Thus, they are a better map of Western interest than of local custom and organization. Models, then, are most useful when we consider them in the context they were created. What was the cartographer trying to achieve? How does this influence what is depicted in the map?

  « As a branch of human endeavor, cartography has a long and interesting history that well reflects the state of cultural activity, as well as the perception of the world, in different periods. … Though technical in nature, cartography, like architecture, has attributes of both a scientific and artistic pursuit, a dichotomy not satisfactorily reconciled in all presentations. »

  Norman J.W. Thrower11

  Maps can influence territories: This problem was part of the central argument put forth by Jane Jacobs in her groundbreaking work, The Death and Life of Great American Cities. She chronicled the efforts of city planners who came up with elaborate models for the design and organization of cities without paying any attention to how cities actually work. They then tried to fit the cities into the model. She describes how cities were changed to correspond to these models, and the often negative consequences of these efforts. “It became possible also to map out master plans for the statistical city, and people take these more seriously, for we are all accustomed to believe that maps and reality are necessarily related, or that if they are not, we can make them so by altering reality.” 12

  Jacobs’ book is, in part, a cautionary tale of what can happen when faith in the model influences the decisions we make in the territory. When we try to fit complexity into the simplification.

  _

  Jacobs demonstrated that mapping the interaction between people and sidewalks was an important factor in determining how to improve city safety.

  «In general, when building statistical models, we must not forget that the aim is to understand somethin
g about the real world. Or predict, choose an action, make a decision, summarize evidence, and so on, but always about the real world, not an abstract mathematical world: our models are not the reality. »

  David Hand13

  Conclusion

  Maps have long been a part of human society. They are valuable tools to pass on knowledge. Still, in using maps, abstractions, and models, we must always be wise to their limitations. They are, by definition, reductions of something far more complex. There is always at least an element of subjectivity, and we need to remember that they are created at particular moments in time.

  This does not mean that we cannot use maps and models. We must use some model of the world in order to simplify it and therefore interact with it. We cannot explore every bit of territory for ourselves. We can use maps to guide us, but we must not let them prevent us from discovering new territory or updating our existing maps.

  While navigating the world based on terrain is a useful goal, it’s not always possible. Maps, and models, help us understand and relate to the world around us. They are flawed but useful. In order to think a few steps ahead we must think beyond the map.

  Model of Management

  Let’s take a model of management. There are hundreds of them, dating back at least to the Scientific Theory of Management by Frederick Taylor, which had factory managers breaking down tasks into small pieces, forcing their workers to specialize, and financially incentivizing them to complete those tasks efficiently. It was a brute force method, but it worked pretty well.

  As time went on and the economy increasingly moved away from manufacturing, other theories gained popularity, and Taylor’s scientific model is no longer used by anyone of note. That does not mean it wasn’t useful: For a time, it was. It’s just that reality is more complicated than Taylor’s model. It had to contend with at least the following factors:

  As more and more people know what model you’re using to manipulate them, they may decide not to respond to your incentives.

  As your competitors gain knowledge of the model, they respond in kind by adopting the model themselves, thus flattening the field.

  The model may have been mostly useful in a factory setting, and not in an office setting, or a technology setting.

  Human beings are not simple automatons: A more complete model would hone in on other motivations they might have besides financial ones.

  And so on. Clearly, though Taylor’s model was effective for a time, it was effective with limitations. As with Einstein eclipsing Newton, better models came along in time.

  Maps Are Necessarily Flawed

  Maps, or models, are necessary but necessarily flawed. Lewis Carroll once jabbed at this in a story called Sylvie and Bruno, where one of the characters decided that his country would create a map with the scale of one mile to one mile. Obviously, such a map would not have the limitations of a map, but it wouldn’t be of much help either. You couldn’t use it to actually go anywhere. It wouldn’t fit in your pocket or your car. We need maps to condense the territory we are trying to navigate.

  _

  Illustration from the first edition of Sylvie and Bruno, published in 1889

  I’m no genius. I’m smart in spots—but I stay around those spots.

  Thomas Watson1

  The People Who Appear in this Chapter

  Norgay, Tenzing, born Namgyal Wangdi.

  1914-1986 - Nepali Sherpa mountaineer. Time named him one of the 100 most influential people of the 20th century.

  Gawande, Atul.

  1965 - American surgeon, writer, and public health researcher. He practices medicine in Boston, is a professor at Harvard University, and has been a staff writer for The New Yorker since 1998.

  Elizabeth I.

  1533-1603 - Queen of England and Ireland. One of the most famous monarchs of all time, her image and legacy continue to capture the imagination. Elizabeth was a great orator, could speak about 11 languages, and wrote her own speeches and letters.

  Circle of Competence

  When ego and not competence drives what we undertake, we have blind spots. If you know what you understand, you know where you have an edge over others. When you are honest about where your knowledge is lacking you know where you are vulnerable and where you can improve. Understanding your circle of competence improves decision-making and outcomes.

  In order to get the most out of this mental model, we will explore the following:

  What is a circle of competence?

  How do you know when you have one?

  How do you build and maintain one?

  How do you operate outside of one?

  What is a circle of competence? Imagine an old man who’s spent his entire life up in a small town. He’s the Lifer. No detail of the goings-on in the town has escaped his notice over the years. He knows the lineage, behavior, attitudes, jobs, income, and social status of every person in town. Bit by bit, he built that knowledge up over a long period of observation and participation in town affairs.

  The Lifer knows where the bodies are buried and who buried them. He knows who owes money to whom, who gets along with whom, and who the town depends on to keep spinning. He knows about that time the mayor cheated on his taxes. He knows about that time the town flooded, how many inches high the water was, and exactly who helped whom and who didn’t.

  Now imagine a Stranger enters the town, in from the Big City. Within a few days, the Stranger decides that he knows all there is to know about the town. He’s met the mayor, the sheriff, the bartender, and the shopkeeper, and he can get around fairly easily. It’s a small town and he hasn’t come across anything surprising.

  In the Stranger’s mind, he’s convinced he pretty much knows everything a Lifer would know. He has sized up the town in no time, with his keen eye. He makes assumptions based on what he has learned so far, and figures he knows enough to get his business done. This, however, is a false sense of confidence that likely causes him to take more risks than he realizes. Without intimately knowing the history of the town, how can he be sure that he has picked the right land for development, or negotiated the best price?

  After all, what kind of knowledge does he really have, compared to the Lifer?

  The difference between the detailed web of knowledge in the Lifer’s head and the surface knowledge in the Stranger’s head is the difference between being inside a circle of competence and being outside the perimeter. True knowledge of a complex territory cannot be faked. The Lifer could stump the Stranger in no time, but not the other way around. Consequently, as long as the Lifer is operating in his circle of competence he will always have a better understanding of reality to use in making decisions. Having this deep knowledge gives him flexibility in responding to challenges, because he will likely have more than one solution to every problem. And this depth increases his efficiency—he can eliminate bad choices quickly because he has all the pieces of the puzzle.

  What happens when you take the Lifer/Stranger idea seriously and try to delineate carefully the domains in which you’re one or the other? There is no definite checklist for figuring this out, but if you don’t have at least a few years and a few failures under your belt, you cannot consider yourself competent in a circle.

  «We shall be unable to turn natural advantage to account unless we make use of local guides.»

  Sun Tzu2

  For most of us, climbing to the summit of Mount Everest is outside our circles of competence. Not only do we have no real idea how to do it, but—even more scary—should we attempt it, we don’t even know what we don’t know. If we studied hard, maybe we’d figure out the basics. We’d learn about the training, the gear, the process, the time of year, all the things an outsider could quickly know. But at what point would you be satisfied that you knew enough to get up there, and back, with your life intact? And how confident would you be in this assessment?

  There are approximately 200 bodies on Everest (not to mention the ones that have been removed). All of those people t
hought they could get up and down alive. The climate preserves their corpses, almost as a warning. The ascent to the summit takes you by the bodies of people who once shared your dreams.

  Since the first recorded attempts to climb Everest in 1922, all climbers have relied on the specialized knowledge of the Sherpa people to help navigate the terrain of the mountain. Indigenous to the region, Sherpas grew up in the shadows of the mountain, uniquely placed to develop the circle of competence necessary to get to the top.

  Sherpa Tenzing Norgay led the team that made the first ascent3, and a quarter of all subsequent ascents have been made by Sherpas (some going as many as 16 times). 4,5 Although the mountain is equally risky for everyone, most people who climb Everest do it once. For the Sherpas, working and climbing various parts of the mountain is their day job. Would you try to climb Everest without their help?

  _

  Sherpa Tenzing Norgay and his ilk are the real lifers. Yet strangers often ignore their advice much to their peril.

  The physical challenges alone of reaching the summit are staggering. It is a region that humans aren’t suited for. There isn’t enough oxygen in the air and the top is regularly pummeled by winds of more than 150 miles an hour—stronger than a Category 5 hurricane. You don’t get to the top on a whim, and you don’t survive with only luck. Norgay worked for years as a trekking porter, and was part of a team that tried to ascend Everest in 1935. He finally succeeded in reaching the summit in 1953, after 20 years of climbing and trekking in the region. He developed his expertise through lots of lucky failures. After Everest, Norgay opened a mountaineering school to train other locals as guides, and a trekking company to take others climbing in the Himalayas.