In The United States of Paranoia: A Conspiracy Theory, Walker, the books editor at Reason magazine, examines a litany of conspiracy theories, ranging from the Kennedy assassination to devil-worshipping cults. It’s a masterful assessment that will have even the most stalwart reader looking over his shoulder.

You write that paranoia and conspiracy theories have been around since America’s inception. What do our conspiracy theories say about us as a culture?

You can learn a lot about a culture from what it’s afraid of. When a conspiracy theory catches on, it reveals some truths about the anxieties and experiences of the people who believe and repeat that story, whether or not it’s true. It’s no surprise, for instance, that people who feel like they’re losing control over their lives would be attracted to stories in which cabals are plotting to erode American liberty and sovereignty. Or that black Americans who have had to deal with high-handed or abusive treatment from white doctors would believe in a white plot to inject black babies with AIDS. Powerful people frequently have conspiracy theories, too: historians often have a hard time telling which slave rebellions were real and which ones were just imagined by nervous planters who couldn’t see two slaves talking without worrying that a plot was afoot. Add all these up and you get a panoramic portrait of the fears that have afflicted Americans in different times and places.

Is there a certain level of fear or skepticism that is useful?

Skepticism is a good thing, and that includes skepticism toward the officially sanctioned narratives as well as skepticism toward conspiracy theories. I have a chapter in the book about the Watergate-era probes of the CIA, FBI, and other agencies, when senators and investigative journalists uncovered a host of ugly abuses. Some of that stuff has a real hall-of-mirrors quality. The FBI’s COINTELPRO, for example, was basically a government conspiracy to defeat alleged subversive conspiracies by convincing the conspirators that they were being conspired against. The more I think about that one, the more I need an aspirin.

What is so appealing about the idea behind The Matrix—that this is all an illusion?

The most fascinating thing about it, to me, is the way these stories about people trapped in false worlds then produce imaginary worlds that people are eager to be a part of: games, fan cultures, and so on. People may hate the thought of being forced or tricked into a false world, but they’ll jump at the opportunity to enter one at will. I have a quote in the book from the comics writer Grant Morrison: “We should be grateful that we live in a culture so insulated from true horror it can afford to play with fear as entertainment.” Now, I don’t think we’re suffering from a shortage of true horrors. But I think he was onto something. Conspiracy stories aren’t just about anxiety. They can be a leisure activity.