Scientists' favourite jokes

"A statistician gave birth to twins, but only had one of them baptised. She kept the other as a control." David Spiegelhalter, professor of statistics, University of Cambridge

 "A psychoanalyst shows a patient an inkblot, and asks him what he sees. The patient says: "A man and woman making love." The psychoanalyst shows him a second inkblot, and the patient says: "That's also a man and woman making love." The psychoanalyst says: "You are obsessed with sex." The patient says: "What do you mean I am obsessed? You are the one with all the dirty pictures.''"
 Richard Wiseman, professor of public understanding of psychology, University of Hertfordshire

 "Don't worry. You're not deluded. You only think you are."
 Uta Frith, professor in cognitive neuroscience, University College London
 "After sex, one behaviourist turned to another behaviourist and said, "That was great for you, but how was it for me?"
 Charles Fernyhough, professor of psychology at the University of Durham

The Observer asked a sample of great minds for their favourite jokes.