George Washington's Rules, Rule #37

Working my way through George Washington's Rules, we are up to Rule #37 which states:

 In speaking to men of quality do not

lean nor look them full in the face, nor

approach too near them at lest keep a full pace from them. 

 I think this rule must have been based on societal norms of the time. For instance, nowadays, when you are speaking to someone, leaning toward them and looking them straight in the eye IS considered polite. It is still true, though, that people like to have about 12-18" of personal space.