I thought of Derek's post when I listened to the part of the Corbett Report podcast, Episode 050 The C Word, 'c' referring to the word 'conspiracy', in the expression conspiracy theory (ist, ists).
So I decided to plug 'conspiracy theorists' into ngram ...
...an expression supposedly dreamt up by the CIA in order to undermine those who criticised the Warren Commission's
Whilst over in the UK the expression took a little longer (between 1970 - 1975) to appear in the British English corpus of literature.
Click the images for a clearer view but better still, do your own analysis using ngram.
Update 1st June 2011. In his Nobel lecture, Pinter says,
"Language is actually employed to keep thought at bay."As I read Pinter's speech I couldn't help but think that the expression, conspiracy theorist, is another expression employed to keep thought at bay.
Here's the part of the speech where the expression appears,
"Listen to all American presidents on television say the words, 'the American people', as in the sentence, 'I say to the American people it is time to pray and to defend the rights of the American people and I ask the American people to trust their president in the action he is about to take on behalf of the American people.'
"It's a scintillating stratagem. Language is actually employed to keep thought at bay. The words 'the American people' provide a truly voluptuous cushion of reassurance. You don't need to think. Just lie back on the cushion. The cushion may be suffocating your intelligence and your critical faculties but it's very comfortable."