Unfortunately there has been little research carried out into what kind of events trigger conspiracy theories, who tends to believe them, and why. We do know, however, that people who believe in one theory are more likely to believe in others: there is a good chance that someone who believes the moon landings were faked will also believe that JFK was killed by a second gunman from the infamous grassy knoll.
There are some variations in who believes what, though, as shown by an as yet unpublished study I carried out recently in the UK with psychologist Chris French at Goldsmiths College, London. We found that beliefs in JFK conspiracies are highest among people aged 36 and over, while those between 20 and 35 are most likely to see a conspiracy behind the 9/11 attacks. Surprisingly, perhaps, the youngest age group - 19 and under - are least likely to endorse any theory.
One possible explanation of these findings is the phenomenon known as "flashbulb memory" - the recall of a sudden event, often shocking and international in scale, that affects individuals on a personal level. This type of memory is more easily formed when individuals are between 20 and 35 years old, so for different generations there are certain events - the assassination of JFK, space shuttle Challenger exploding on take-off, the death of Princess Diana - that tend to trigger flashbulb memories. Some of these iconic, shared events can provide fertile ground in which conspiracy theories are sown.
Age is not the only demographic to influence conspiracy beliefs. Several US studies have found that ethnic minorities - particularly African and Hispanic Americans - are far more believing of conspiracy theories than white Americans. In our recent UK study, we found a similar race effect, coupled with an even stronger association between income and belief levels. People who describe themselves as "hard up" are more likely to believe in conspiracies than those with average income levels, while the least likely to believe are the well off.
How can we account for the link between race, income level and conspiracy theories? Theorists tend to show higher levels of anomie - a general disaffection or disempowerment from society. Perhaps this is the underlying factor that predisposes people more distant from centres of power - whether they be poorer people or those from ethnic minorities - to believe in conspiracies.
So what kind of thought processes contribute to belief in conspiracy theories? A study I carried out in 2002 explored a way of thinking sometimes called "major event - major cause" reasoning. Essentially, people often assume that an event with substantial, significant or wide-ranging consequences is likely to have been caused by something substantial, significant or wide-ranging.
I gave volunteers variations of a newspaper story describing an assassination attempt on a fictitious president. Those who were given the version where the president died were significantly more likely to attribute the event to a conspiracy than those who read the one where the president survived, even though all other aspects of the story were equivalent.
To appreciate why this form of reasoning is seductive, consider the alternative: major events having minor or mundane causes - for example, the assassination of a president by a single, possibly mentally unstable, gunman, or the death of a princess because of a drunk driver. This presents us with a rather chaotic and unpredictable relationship between cause and effect. Instability makes most of us uncomfortable; we prefer to imagine we live in a predictable, safe world, so in a strange way, some conspiracy theories offer us accounts of events that allow us to retain a sense of safety and predictability.
Other research has examined how the way we search for and evaluate evidence affects our belief systems. Numerous studies have shown that in general, people give greater attention to information that fits with their existing beliefs, a tendency called "confirmation bias". Reasoning about conspiracy theories follows this pattern, as shown by research I carried out with Marco Cinnirella at the Royal Holloway University of London, which we presented at the British Psychological Society conference in 2005.
The study, which again involved giving volunteers fictional accounts of an assassination attempt, showed that conspiracy believers found new information to be more plausible if it was consistent with their beliefs. Moreover, believers considered that ambiguous or neutral information fitted better with the conspiracy explanation, while non-believers felt it fitted better with the non-conspiracy account.
The same piece of evidence can be used by different people to support very different accounts of events.
This fits with the observation that conspiracy theories often mutate over time in light of new or contradicting evidence. So, for instance, if some new information appears to undermine a conspiracy theory, either the plot is changed to make it consistent with the new information, or the theorists question the legitimacy of the new information. Theorists often argue that those who present such information are themselves embroiled in the conspiracy. In fact, because of my research, I have been accused of being secretly in the pay of various western intelligence services (I promise, I haven't seen a penny).
It is important to remember that anti-theorists show a similar bias: they will seek out and evaluate evidence in a way that fits with the official or anti-conspiracy account. So conspiracy theorists are not necessarily more closed-minded than anti-theorists. Rather, the theorist and anti-theorist tend to pursue their own lines of thought and are often subject to cognitive biases that prevent their impartial examination of alternative evidence.
How then can we predict who will become believers and non-believers? My hunch is that a large part of the explanation lies in how individuals form aspects of their social identities such as ethnicity, socioeconomic status and political beliefs. The reasoning and psychological biases that create believers or their opposites are fostered by social origins.
For conspiracy believer and non-believer alike, there is a kind of truth out there. It's just a rather different truth that each seeks.
, but its called 'Voodoo Histories'
