Laughter is social lubricant. There is lots of research on this: people laugh more in groups; inferiors laugh more than superiors; nervous people laugh at thems

Laughter is social lubricant. There is lots of research on this: people laugh more in groups; inferiors laugh more than superiors; nervous people laugh at themselves, and laughing at yourself is also kind of way to efface yourself and show that you are part of a group. If only HNers would read basic Intro to Psychology books, there would not be so many chimes of "I noticed this too" and, hopefully, more discussion of what actually goes on in the world and how things actually work.