The internet currently has two very different models of social networking. There is, of course, Facebook – a massive sprawl of friends and acquaintances that allows us to keep track of people we know in real life. I’m “friends” with my grandmother, a bunch of second cousins and it seems like most of my high school class. The defining feature of this network is its focus on “social closeness” – I want to keep track of these people because I have some kind of connection to them. We are all part of the same “clan”.

The second model of online social networking is Twitter. The interesting thing about Twitter is that it encourages us to follow people who we have no social connection to at all. If I follow Ashton Kutcher or LeBron James or Margaret Atwood it’s not because I know them from high school, or because I met Ashton at a party last week. Instead, it’s because we share a set of common interests and beliefs. In other words, our connection is abstract – it’s rooted in perceptions of social similarity, and not literal social closeness.