abstract and paper too verbose... simply: "By examining precisely who had the different response times -- friends, colleagues, or acquaintances -- Uzzi and Wuchty uncovered a more telling pattern: the fastest responses went to friends and that the slowest responses went to acquaintances, with colleagues somewhere in between. Having established this, the researchers could use the response times to predict who was a friend, colleague, or acquaintance without checking the employee survey at all. According to Uzzi, it should be possible to go a step further and rank a person's friends just by peeking at their inbox and outbox and seeing who gets the fastest responses." \\ Duh! - Adriano