While the capacity for our social networks has no real limit, social scientists agreed upon a threshold by which we can comfortably manage our relationships. That magical number, according to Bernard and Killworth (1979), is approximately 140 people. Beyond that, members will naturally sub-divide so they can better understand their position in the group and function effectively. Extending past this core group, people can have roughly 2,500 in their informal network. If that sounds like a high number, just think about every memorable acquaintance, colleague, consultant, medical professional, vendor, classmate, and customer service representative. It adds up pretty quickly.

It goes to show that new technologies do value and use this knowledge to design new applications. Social media platform Path draws on this number directly – it is used to share life’s moments, but users have to limit followers to 150. It’s a closed network where followers have to be approved and the private space allows for more control over the social sharing. (It is one of my favourite apps!)