December 21, according to much-hyped misreadings of the Mayan calendar, will mark the end of the world. It's not the first "end is nigh" proclamation—and it's unlikely to be the last. That's because, deep down for various reasons, there's something appealing—at least to some of us—about the end of the world.

Enjoy the Self-Fulfilling Prophecy

University of Minnesota neuroscientist Shmuel Lissek, who studies the fear system, believes that at its heart, the concept of doomsday evokes an innate and ancient bias in most mammals. "The initial response to any hint of alarm is fear. This is the architecture with which we’re built," Lissek says. Over evolutionary history, organisms with a better-safe-than-sorry approach survive. This mechanism has had consequences for both the body and brain, where the fast-acting amygdala can activate a fearful stress response before "higher" cortical areas have a chance to assess the situation and respond more rationally.

But why would anyone enjoy kindling this fearful response? Lissek suspects that some apocalyptic believers find the idea that the end is nigh to be validating. Individuals with a history of traumatic experiences, for example, may be fatalistic. For these people, finding a group of like-minded fatalists is reassuring. There may also be comfort in being able to attribute doom to some larger cosmic order—such as an ancient Mayan prophecy. This kind of mythology removes any sense of individual responsibility.

There’s an even broader allure to knowing the precise end date. "Apocalyptic beliefs make existential threats—the fear of our mortality—predictable," Lissek says. Lissek, in collaboration with National Institute of Mental Health neuroscientist Christian Grillon and colleagues, has found that when an unpleasant or painful experience, such as an electric shock, is predictable, we relax. The anxiety produced by uncertainty is gone. Knowing when the end will come doesn't appeal equally to everyone, of course—but for many of us it's paradoxically a reason to stop worrying.

This also means people can focus on preparing. Doomsday preppers who assemble their bunker and canned food, Lissek believes, are engaged in goal-oriented behaviors, which are a proven therapy in times of trouble.

The Power of Knowledge

Beyond the universal aspects of fear and our survival response to it, certain personality traits may make individuals more susceptible to believing it's the end of the world. Social psychologist Karen Douglas at the University of Kent studies conspiracy theorists and suspects that her study subjects, in some cases, share attributes with those who believe in an impending apocalypse. She points out that, although these are essentially two different phenomena, certain apocalyptic beliefs are also at the heart of conspiracy theories—for example, the belief that government agencies know about an impending disaster and are intentionally hiding this fact to prevent panic.

"One trait I see linking the two is the feeling of powerlessness, often connected to a mistrust in authority," Douglas says. Among conspiracy theorists, these convictions of mistrust and impotence make their conspiracies more precious—and real. "People feel like they have knowledge that others do not."

Relatively few studies exist on the individuals who start and propagate these theories. Douglas points out that research into the psychology of persuasion has found that those who believe most are also most motivated to broadcast their beliefs. In the Internet age, that's an easier feat than ever before.

Lessons from Dystopia

Steven Schlozman, drawing both from his experiences as a Harvard Medical School child psychiatrist and novelist (his first book recounts a zombie apocalypse) believes it's the post-apocalyptic landscape that fascinates people most.

"I talk to kids in my practice and they see it as a good thing. They say, 'life would be so simple—I'd shoot some zombies and wouldn't have to go to school,'" Schlozman says. In both literature and in speaking with patients, Schlozman has noticed that people frequently romanticize the end times. They imagine surviving, thriving and going back to nature.

Schlozman recently had an experience that eerily echoed Orson Welles's 1938 The War of the Worlds broadcast. He was discussing his book on a radio program and they had to cut the show short when listeners misconstrued his fiction for fact. He believes the propensity to panic is not constant in history but instead reflects the times. In today's complicated world with terrorism, war, fiscal cliffs and climate change, people are primed for panic.

"All of this uncertainty and all of this fear comes together and people think maybe life would be better" after a disaster, Schlozman says. Of course, in truth, most of their post-apocalyptic dreams are just fantasies that ignore the real hardships of pioneer life and crumbling infrastructure. He points out that, if anything, tales of apocalypse, particularly involving zombies, should ideally teach us something about the world we should avoid—and how to make necessary changes now.