Randomized Instruction Sheets A set of 20 Randomized Instruction Sheets for use with these experiments is now available: Click here for html version If you want to print the sheets, click here for the pdf version You will require Acrobat Reader for the pdf version. Introduction The feeling of being looked at from behind is remarkably common. So is the experience of looking at someone from behind and finding that they turn round. Surveys show that about 90% of the population have personally experienced these phenomena. If people really can tell when they are being looked at...