conspiracy theory an element within a belief system in which social consequences, identified as harmful or unwanted, are seen as arising from the activities of groups believed able to influence the operation of power, economic decision-making, etc., in surreptitious ways. Members of successful religious or ethnic minority groups, political extremists, freemasons, etc., may be identified in such theories, e.g. the ‘witch hunt’ of members of the Communist Party (and alleged fellow travellers) carried out by Joseph McCarthy in the United States in the early 1950s, or the so-called ‘Doctors’ Plot’ in the USSR prior to Stalin's death in 1953, in which Jewish doctors were accused of plotting to poison Stalin. Whether or not there are elements of truth in the claims made in such conspiracy theories, it is the exaggerated nature of the claims, and the often slender evidence advanced, that leads conspiracy theories to be regarded as a phenomenon requiring explanation rather than being seen as ‘true’ theories. Thus, they might be explained as arising from the believers’ powerlessness and structurally precarious situation, and the need for the believers themselves to find a reason’ for this and some hope of resolution.