Professor Robert Cialdini, emeritus professor of psychology ("and marketing") at Arizona State, was purporting to talk about clarity of language. "Cognitive chute" was his best shot.

Prof Cialdini had been called in to answer the question of the question. You know the one: "Do you agree that Scotland should be an independent country?" Alex Salmond wants to make the inquiry in 2014. A lot of people – the professor, a former Chancellor, purveyors of opinion polls – think he has no right.