A friend of mine recently convinced me to watch "Loose Change", a documentary about the alleged conspiracy and cover-up of the 9/11 terrorist attacks by the U.S. government. I'm not a big fan of conspiracy theories, and I knew little of the specific theories surrounding 9/11, but I watched the film with the most open mind I could muster.

I found the film to be very engaging, and though I didn't buy the film's conspiracy and cover-up hypotheses, it did make me question whether something important was being kept secret. Seeing the conspiracy theories laid out so confidently and so sensationalistically also helped me to understand why one-third to one-half of Americans believe that our government either was somehow involved in the attacks or covered up information about them.

One reason I generally have trouble accepting conspiracy theories is that they're usually based on far-fetched claims that are nearly impossible to disprove, or prove. My skepticism is further strengthened by the fact that we humans have an assortment of cognitive biases that can distort our judgments and allow us to maintain beliefs despite overwhelming evidence to the contrary. Some of these biases include the tendency to see patterns where none exist, and to interpret new information and recall old information in ways that confirm our expectations and beliefs. However, most of the time we're unaware of these biases and overly confident that our perceptions represent the objective truth.

This is not to say that conspiracies never happen, or that I'm immune from engaging in my own conspiracy-like thinking sometimes. It just means that one of my own biases is to doubt these sorts of theories.

Rather than speculating about the existence of specific conspiracies, I find a far more intriguing topic to be the psychology behind conspiracy thinking. Fortunately, an excellent book called Empire of Conspiracy by Tim Melley explores this issue.

Melley seeks to explain why conspiracy theories and have become so pervasive in American culture in recent decades. He discusses some of the paranoia behind our obsessions with political assassinations, and race relations, stalkers, mind control, bureaucracies, and the power of corporations and governments.

Melley proposes that conspiracy thinking arises from a combination of two factors, when someone: 1) holds strong individualist values and 2) lacks a sense of control. The first attribute refers to people who care deeply about an individual's right to make their own choices and direct their own lives without interference or obligations to a larger system (like the government). But combine this with a sense of powerlessness in one's own life, and you get what Melley calls agency panic, "intense about an apparent loss of autonomy" to outside forces or regulators.

Although Melley doesn't present any empirical data to show that conspiracy thinking has been increasing for these reasons, some research by psychologist Jean Twenge is consistent with his hypotheses. Twenge's research examines how Americans' traits have been changing over the past several decades. She reviews the results of hundreds of studies published from the 1960s through the end of the century, looking at the personality scores for each year. For example, she finds that trait anxiety (or ) has been rising dramatically in both children and adults over this period.

In another study, she shows that people have come to hold an increasingly stronger external " "; this refers to the feeling that external forces are determining what happens to you, as opposed to an internal locus of control, the feeling that you dictate your own outcomes. Twenge suggests that the stronger external locus of control reflects our ever-increasing exposure to uncontrollable events and a rise in the "victim mentality" of our culture. (Is this sounding familiar?)

Individualistic values have also been getting stronger in our culture, with greater importance attached to personal freedoms and self-reliance. The U.S. currently ranks highest in individualism compared to all other nations in the world.

The rise in anxiety, individualism, and external locus of control may therefore underlie the rise in conspiracy thinking. This is somewhat troubling because these personality trends show no sign of leveling off. In fact, given the current pace of globalization and the "Americanization" of other countries, it seems likely that these personality traits (and conspiracy thinking) will be increasing elsewhere too.

But what's the actual appeal of believing in conspiracy theories? What purpose do they serve people?

For one thing, conspiracy theories help us cope with distressing events and make sense out of them. Conspiracies assure us that bad things don't just happen randomly. Conspiracies tell us that someone out there is accountable, however unwittingly or secretly or incomprehensibly, so it's possible to stop these people and punish them and in due course let everyone else re-establish control over their own lives. Conspiracies also remind us that we shouldn't blame ourselves for our predicaments; it's not our fault, it's them! In these ways, believing in conspiracies serves many of the same self-protective functions as scapegoating.

In addition to the changes in personality, conspiracy theories are also growing more popular because of the mass media, which circulates these ideas to a wider audience and indoctrinates more believers. Plus, the sheer amount of information in today's media increases the odds that someone will detect "coincidences" or "patterns" that serve to fuel these beliefs. These trends in the media won't be reversing themselves anytime soon either.

Does all this mean we should expect even more conspiracy theorizing and paranoia to come? Will conspiracy theories ever become a dominant ideology in our culture the way scapegoating sometimes is in other cultures?

It's not clear whether we've reached any sort of tipping point yet. But if polls are any indication, the events of 9/11 may have transformed conspiracy theories from "implausible visions of a lunatic fringe" to a mainstream response to the most disturbing of events.

How are we to prevent this kind of thinking from taking us hostage?

(This post was co-authored by Josh Foster.)