Why did Marc hang this poster on his office door for so many years?  Like much of Marc’s humor, the poster mocks the human tendency to systematize. It recognizes the irrational aspects of formal scholarly study.  The joke presumes that, as sociologists-in-training, students will at times feel utterly frustrated, even defeated.

The joke’s punchline is that sociology students would adhere to a precise, rigorous process even in banging their heads to relieve stress.  In other words, by the time you’re overwhelmed by the constraints of the discipline, its conventions have conditioned you to follow its rules even in resisting them.