Ben Hyde pointed me at the review of The Media Equation, one passage from which intrigued me so much I have to buy it: "Pick a finding describing a social rule governing people's interaction with each other. One example, which is used in the book, is 'people like other people whose personalities are like their own.' So you have a rule which describes social behaviour. According to the media equation, media and real life are the same, so people should also like media whose personalities are like their own". All of which is very interesting, especially if you're thinking about the intrinsic properties of inbuilt social grammar. Which I am.

See also: 14 Principles of Polite Apps.