others agreement with the statements, as well as their perceived retrospective attitudes. They found that participants significantly underestimated how much the conspiracy theories influenced their own attitudes.In an earlier study, McHoskey (1995) predicted that conspiracy theories concerning the assassination of JFK, and possibly all conspiracy theories, would continue endlessly because of the processes of biased assimilation and attitude polarisation. In the first instance, when opposing sides were presented with the same evidence, McHoskey (1995) showed that there was a tendency to uncritically accept evidence that was supportive of ones own argument, while scrutinising and discrediting contrary evidence. When participants were presented with mixed evidence, there were signs of attitude polarisation, with participants reporting that they were more in favour of their initial viewpoint, rather than reporting a reversal of their beliefs. In a similar vein, Leman and Cinnirella (2007) found that conspiracy believers judged fictitious accounts of an assassination more plausible if it was consistent with their beliefs, a tendency called confirmation bias. Conspiracy believers found that ambiguous information fitted better with a conspiracist explanation, whereas non-believers believed it suited a non-conspiracist account. In other words, the same piece of information can be used to support very different accounts, depending on who it is presented to.Individual differences Perhaps one of the most important conclusions to emerge from the handful of studies to focus explicitly on the individual antecedents of belief in conspiracy theories was Goertzels (1994) assertion that conspiracy beliefs form part of a monological belief system. This allows conspiracy theorists to easily assimilate explanations for new phenomena that would otherwise be difficult to understand or would threaten their existing beliefs. Recent work supports this, showing that those who more strongly endorsed 9/11 conspiracy theories were also more likely to believe in other, seemingly unrelated conspiracy theories (Swami et al., in press).Related work in this area has provided some support for early sociological work on conspiracy theories. For example, studies have variously reported significant associations between conspiracist ideation and anomie, distrust in authority, political cynicism, powerlessness and self-esteem (Abalakina-Paap et al., 1999; Goertzel, 1994; Swami et al., in press). Interestingly, at least two studies have also reported significant associations between conspiracist beliefs and authoritarianism (Abalakina-Paap et al., 1999; McHoskey, 1995), which the former study explained as a manifestation of the tendency of believers in conspiracy theories to blame outgroups for problems experienced by the ingroup.Most recently, Swami and colleagues (in press) found that 9/11 conspiracist beliefs were significantly associated with the Big Five personality factor of Openness to Experience, with the authors suggesting that intellectual curiosity, an active imagination, and a proclivity for new ideas results in greater exposure and subsequent assimilation of conspiracist beliefs. Interestingly, Swami et al. (in press) also found that individuals who more strongly believed in conspiracy theories were more supportive of democratic principles. They went on to argue that, for participants who reject the political system as undemocratic, mainstream explanations of social events are unsatisfactory precisely because they are provided by the very sources that these participants doubt.Good or bad? What practical impact do conspiracy theories have?