Dept. of Misinformation

Whether or not he can bring America’s jobs home, Donald Trump is certainly keeping one group of workers gainfully employed: fact checkers. The cottage industry that has arisen as a result of Trump’s refusal to acknowledge error or prevarication in his campaign shows no sign of shrinking. Which is ostensibly a good thing. As Michael Kinsley wrote in Vanity Fair, it has at least shifted public focus from gaffes—those old standbys of campaigns—to lies. On the other hand, even when exposed, the falsehoods—whether about rates of crime committed by immigrants in the United States or America being the highest-taxed country in the world, or Trump doing more for veterans than anyone else has—have done little to shake Trump’s large and devoted following. A similar dynamic played out in the Brexit vote, where the leaders of the “leave” campaign repeated exaggerations and fabrications long after they had been publicly disproven. They acted as though the truth were a trivial riposte to the more profound story they were telling.

Lies and half-truths have always been put to use by the unscrupulous in the political arena, but this bare-faced indifference to truth is a rare and more disturbing phenomenon. The timing could not be better then, for Daniel J. Levitin’s new book, A Field Guide to Lies: Critical Thinking in the Information Age, a survival manual for the post-factual era. Political campaigners are hardly the only guilty parties. Dismayed by the virulent spread of misinformation in the socially networked world, Levitin offers a set of intellectual tools to help distinguish the real from the unreal, and often surreal. “Sometimes the people giving you the facts are hoping that you’ll draw the wrong conclusion; sometimes they don’t know the difference themselves,” Levitin says. “And misinformation is promiscuous—it consorts with people of all social and educational classes, and turns up in places you don’t expect.”

A McGill University psychologist and behavioural neuroscientist, Levitin is celebrated for his 2006 bestseller, This Is Your Brain on Music: Understanding a Human Obsession. But this book is a more direct descendent of his 2014 work, The Organized Mind: Thinking Straight in an Age of Information Overload. Both works promote intellectual hygiene through rigorous mental exercise. The Organized Mind focuses mainly on the evolutionary reasons we must engage in constant self-questioning. Rationality is an achievement of mental effort, not a natural endowment. Field Guide instructs us in how to interrogate others—even the well-meaning authorities who once enjoyed our automatic trust.

The tone sometimes resembles Baden-Powell’s Scouting for Boys: A Handbook for Instruction in Good Citizenship, worthy and hortatory. Pay critical attention to everything you hear or read, he urges, because no matter what the source, the assertions could be wrong. All received truths and accepted wisdom must be put to the test.

And indeed some of the material he cites is so outrageous it makes his sometimes starchy tone easy to condone. Consider the California anti-marijuana crusaders who claim that grass users in the state have doubled each year since possession laws ceased to be enforced in 1982. As Levitin notes, if there were merely one Californian toker in year one—an unrealistically conservative assumption—annual doubling would raise the druggie count to between 8.6 billion and 11 billion users today. As that result is in excess of the population of the entire earth, you have to wonder what those drug busters have been smoking.

Well-meaning campaigners against anorexia do no better when they claim that the illness kills 150,000 young American women a year. Only about 8,500 girls and young women die of all causes annually.

Equally nonsensical assertions are made by people who ought to know better, Levitin writes: a Science magazine article claims the cost of a telephone call has fallen 12,000 percent in recent years, while a peer-reviewed paper in the Journal of Management Development lauds a customer-care program that reduced consumer complaints by 200 percent. In the real world, when 100 percent of a cake is eaten, there is nothing left but crumbs. And yet serious researchers and writers continue to talk about losses or reductions of more than 100 percent.

Much confusion enters the world through mischievously labelled charts, incomplete graphs and distorting averages. While it is true that humans have on average one testicle, the number is as useful as knowing that the average temperature in Death Valley is a temperate 25°C. Likewise, some of the most confusing, and frequent, political arguments are conducted between people who have an underlying difference in how they define the terms they are using. The crucial debate about inequality in Canada has one character when it focuses on market income inequality and another when the question is income after taxes and transfers.

Interpreting business trends or global temperature movement, say, requires, at the very least, strict attention to baselines, units of measurement and measurement periods. But, as data visualizations and infographics keep growing in popularity, it is worth remembering that not all of the information we get scrolling through charts on Twitter may be put through this rigorous process. “Bad statistics are everywhere,” says Levitin. Because you do not know whom to trust, you need to be capable of testing all assertions for yourself.

That may be easier said than done. One source of honest but potentially devastating error is in the application of probability. Levitin tells of a surgeon who persuaded 90 women from a high-risk group to have their healthy breasts removed because he had understood that 93 percent of breast cancers occurred in women with the related genetic markers. But as almost 60 percent of all women fall into this high-risk group and only eight percent of women overall have cancer, his patients’ risk of getting breast cancer was actually only 13 percent—not 93 percent as he thought.

Levitin offers a relatively simple way of calculating conditional probabilities; that is, a determination of probabilities influenced by several factors such as genetic makeup or family history. It is the kind of tool that can help with complex medical and legal decisions.

The news media, too, come in for criticism for sometimes forgetting that “the plural of anecdote is not data,” as Levitin says. The media also rank story ideas according to how much they appeal to the instincts or interests of audiences, and not how they conform to reality, he charges. Five times more people die of stomach cancer than of drowning, but you would not know it from watching or reading the news. Cognitive science has found that media can create huge misperceptions of risk, leading people to pay too much attention to some matters and too little to others. Most of us know rationally there is not a psycho killer or predator on every block, but we nonetheless make decisions for our kids, and ourselves, based on an inflated sense of risk.

Levitin is of less help when it comes to dealing with people who are indifferent or inimical to the truth. Hostility to the gathering and interpretation of information marked the tenure of Prime Minister Stephen Harper and his regressive Conservatives. Nothing symbolized their purposeful retreat into ignorance more than the suspension of the long-form Canadian census and the muzzling of government scientists.

When power ignores the discipline of truth, it is only answerable to competing power. And that can initiate a descent into brutishness. For this, Levitin offers no answer. But for much else in the struggle against error and ignorance, lies and mistakes, he is both engaging and rewarding.