Updated: Jan 20
Not only is it easy to lie with maps. It’s essential. To portray meaningful relationships for a complex, three-dimensional world on a flat sheet of paper or a screen, a map must distort reality. As a scale model, the map must use symbols that almost always are proportionally much bigger or thicker than the features they represent. To avoid hiding critical information in a fog of detail, the map must offer a selective, incomplete view of reality. There’s no escape from the cartographic paradox: to present a useful and truthful picture, an accurate map must tell white lies. Mark Monmonier
How to Lie with Maps takes the reader into the complex world of the cartographer or map maker. Maps have an aura of authority, yet every decision in map design represents a compromise and the final map is one of many possible alternatives. Many decisions go into making a final map. These decisions can lead to results that may not be “wrong” in the common sense of the word, but they can be deceiving.
Monmonier, a Distinguished Professor Emeritus in Geography and the Environment Department at Syracuse University is a preeminent authority on maps and cartography. He has written more than 15 books on cartography, covering topics such as weather maps, news maps, geographic names, coastlines, and map projections. He also edited The History of Cartography, Volume 6 Cartography in the Twentieth Century, which contains more than 500 articles and 1,000 illustrations. Given his extensive experience, he is in an authoritative voice for addressing lying with maps.
Catchy chapter titles make the book’s message memorable. Some of my favorites were “Map Generalization: Little White Lies and Lots of Them,” “Development Maps (Or, How to Seduce the Town Board),” and “Data Maps: A Thicket of Thorny Choices.”
The book is divided into two parts. The first part covers the basics of map making, where Monmonier reveals the myriad of decisions the cartographer faces. Virtually everything you see on a map is either the result of a conscious decision … or the product of a lazy map maker who took shortcuts and relied on the default values of a software application.
Monmonier starts the book with “Elements of the Map,” where he reviews the three basic attributes of any map: scale, projection, and symbolization. The “white lies” that maps tell begin here. Map projections are especially tricky, as there is no way to take a globe and flatten it without distorting its spatial properties. A flat map can only preserve a limited number of properties, such as areas, distance, direction, or gross shape. By selecting an inappropriate map projection, the cartographer can change the relative sizes of countries, draw straight lines which are not the shortest distances between two places, and change the shape of features.
Monmonier moves on to discuss the many cartographic manipulations in “Map Generalization: Little White Lies and Lots of Them.” Here he reveals the twisting and manipulation of the geometry of map features using processes such as selection, simplification, displacement, smoothing, enhancement, and aggregation. As an example, displacement of line features, such as roads, railroads, and rivers is necessary when the map symbols might overlap as a result of the map’s scale. To maintain their relationship, the cartographer may move them apart, so they are clearly separated. This is what is known as “cartographic license,” a term used in the same sense as “poetic license.”
In “Blunders That Mislead,” Monmonier tells tales of both honest mistakes and intentional deception. When the American Automobile Association left the town of Seattle off its road maps, it was a simple mistake caused by carelessness. On the other hand, when a mischievous University of Michigan fan designed the Michigan state road map, the names “goblu” (the University of Michigan’s color) and “beatosu” (for Michigan’s rival Ohio State University) mysteriously appeared in the Ohio portion of the map.
Monmonier wraps up the first half of the book with “Color: Attraction and Distraction.” Color is an essential, but challenging part of map design. Colors seen in traditional physical wall maps, as those often seen in schools, may be misleading. They use a color scale that goes from green, for lower elevations, through yellow and orange, ultimately showing the highest elevations as white. Map readers may associate the greens with fertile areas, while low-elevation areas might be deserts.
In the second part of the book, Monmonier demonstrates how different types of maps lie. This section is engaging and informative. Three of the chapters are especially relevant today.
In ”Maps that Advertise,” Monmonier starts by saying “What do advertising and cartography have in common? Without doubt the best answer is their shared need to communicate a limited version of the truth.” His examples show how advertisers may straighten curvy patterns or reduce distances between places to present a more favorable view; to convince the map reader that places may be closer, more central, or better connected than they are in reality.
“Maps for Political Propaganda” is especially relevant given the current Ukraine-Russia conflict. While the examples may be taken from the past, we see similar maps today. Every country draws its maps and typically will include disputed territory as part of their country. They will use their language and names, as opposed to others’ language and names, for places to promote their political ambitions. Maps can be manipulated to show that an area is surrounded by unfriendly areas, that an area peacefully surrounds other areas, or that a country is minuscule in comparison with its opponents. Monmonier notes that symbols such as arrows and circles or place names can be used as “cartographic assault weapons.” His examples of Nazi propaganda maps are particularly striking.
“Data Maps: A Thicket of Thorny Choices” starts with the observation, “A single set of numerical data can yield markedly dissimilar maps.” Monmonier discusses issues with data aggregation, classification, and the outliers on the visual appearance of maps. Using John Snow’s famous London 1854 cholera map, Monmonier shows how different ways of aggregating street-level data can produce wildly different views of the outbreak pattern.
He also shows how indexes, rates, and rates of change can be used to “shade” a map’s message. He observes that
A useful index for the optimist is one with relatively low values, such as the unemployment rate, if conditions have improved, or an index with comparatively high values, such as employment level, if conditions are worse.
How to Lie with Maps provides insight into the numerous small decisions that go into making a map. With so many decisions, it is clear that any map is only one of many possible maps. Maps can lie, or be misleading, while still being “technically” correct. Monmonier explains the cartographer’s many decisions and discusses “lying” in different types of maps, so the reader will become a more critical map reader.
My only concern is that the Third Edition of the book, reviewed here, was published in 2018 and is somewhat dated. Technology has changed rapidly in the past four years. There are descriptions of manual processes that are no longer in wide use and the author uses terms like “Fast Maps,” which never caught on. While the older information is interesting, it is not current. Despite this minor quibble, the book is a great read and I hope that the author has a new version in the works.
This wraps up our “lying” series of book reviews. How to Lie with Statistics, How Charts Lie, and How to Lie with Maps, are all directed to the public and tell cautionary tales. How to Lie with Statistics led the way; it was a slight volume, written in a light, breezy tone, which used the term “Lie” as a teaser in the title to engage a wide audience in a subject that might otherwise be overlooked. Both How Charts Lie, and How to Lie with Maps followed this successful formula to create engaging reads. What’s next, How to Lie with Data Science?
How to Lie with Maps (3rd edition) at Amazon
Mark Monmonier’s website