Most troubling for journalists is Manjoo’s evidence that even-handed and neutral reports are the most vulnerable to being discredited. He chalks up much of this problem to naïve realism—the psychological shorthand by which we assume the world is as we observe it. “We all think our views are essentially objective and when people disagree with us, we’re apt to decide that they’re not being reasonable,” he writes. “They’re being unfair.” In other words, when people with strongly held views read about, say, the Israelis and the Palestinians, a truly fair and balanced article will be perceived as biased—because to a zealot, even-handedness is bias.

Much of what Manjoo explores is captured in a single word: truthiness. The satirist Stephen Colbert reinvigorated that hoary term during the premiere of his television show in 2005. America, he said, is a nation divided between those who “think with their head” and those who “know with their heart.” Colbert was going after some of the principal PR techniques of the Bush administration, but the problem with things that are just true enough to be believed is far more pervasive.

Manjoo reminds us of how Oprah Winfrey reacted when a memoir she had chosen for her book club, James Frey’s A Million Little Pieces, turned out to be a fraud. At first, Winfrey stood up for the serial fibber—until Frank Rich, who had done yeoman work exposing official truthiness and outright lies, took her to the woodshed. To her credit, Winfrey saw the problem she had created for herself, and invited Frey back onto her show for a national display of contrition. (Also worth noting: even after Frey conceded his fabrications to an irate Winfrey, his book continued to sell many thousands of copies per week.)

Purveyors of truthiness often pander to viewers on issues they know little about. Make up stories about the price of gasoline, says Manjoo, and the easy availability of pricing information will unmask you. But make stuff up about economic policy or the war in Iraq or other “grand, sprawling topics where information is difficult to come by, hard to make sense of, and given to competing explanations and interpretations,” and you can get away with Swift Boating and its spawn.

Here lies the core of Manjoo’s argument: the vast majority of people want their beliefs to be reinforced, not challenged by inconvenient facts. To show the power of desire to warp perception, he focuses on the work of three Stanford University researchers, Lee Ross, Mark Lepper, and Charles Lord. In a 1979 study, the trio asked people with strong views for and against capital punishment to read materials that made substantial arguments for both sides. Then the subjects were asked to discuss their beliefs.

“This led to a funny result,” recounts Manjoo. “People in the study became polarized. Taken together, the two reports they’d been given suggested that it was hard to know whether or not capital punishment deterred crime; after looking at the research, a truly dispassionate person should have moderated his or her extreme position. But people moved the other way instead.”

Surely this is a troubling outcome for journalists who believe in empirical facts as the basis of reality. But for Manjoo, truthiness is only part of the problem. He cites the transformation of CNN’s Lou Dobbs: a man who once revered Big Business is now one of its great detractors, even as he conducts a one-man crusade against illegal immigrants. “When you investigate the roots of bias in the media,” Manjoo writes, “Lou Dobbs’s personal motivations begin to appear less important than the system in which he operates.” And according to the logic of that system, viewers will invariably consider stories on controversial topics “slanted away from their own views.” So why not throw in their collective lot with Dobbs (and Glenn Beck and Olbermann and O’Reilly)? The bottom line: in contemporary media, “objectivity doesn’t pay as well as taking a strong, mad-as-hell stance.”

Dobbs has shifted his approach, says the author, because audiences have bought into the notion that news is not, and cannot be, objective. If viewers outside Dobbs’s target demographic find many of his reports bizarre, so what? Attacks by critics may actually reinforce the broadcaster’s ties to his audience. “Dobbs is not a raving idiot,” Manjoo assures us. “He just plays one on TV. Given the circumstances, he’d be a fool not to.”

David Cay Johnston covers fiscal and budget matters for CJR’s United States Project. He is a reporter with 46 years of experience, including 13 at The New York Times; a columnist for Tax Analysts; teaches tax and regulatory law at Syracuse University Law School; and is president of Investigative Reporters & Editors (IRE). Follow him on Twitter @DavidCayJ.