Two weeks ago, Facebook’s “in house sociologist” Cameron Marlow shared interesting data with The Economist on Facebook users’ social behavior patterns – essentially, while Facebook users have many friends, they only actively communicate with a core group of them.

Today, Marlow has shared additional thoughts and data on the findings in his personal blog. A few highlights:

1) Facebook’s Data Team calculated the number of friends for whom users “maintain” Facebook relationships, where “maintain” is defined as having clicked on a News Feed story or visited their profile more than twice. Their findings?

• For those users with 500 friends, men maintain 7.8% of Facebook relationships, while women maintain 9.4% of Facebook relationships
• For those users with 120 friends, men maintain 15.8% of Facebook relationships, while women maintain 18.3% of Facebook relationships
• For those users with 50 friends, men maintain 18% of Facebook relationships, while women maintain 20% of Facebook relationships

2) The number of maintained, one-way, and reciprocal relationships scales on the order of 10% of total network size, as you would expect.

3) The News Feed is allowing more people to stay connected. As Facebook’s Marlow says,

The stark contrast between reciprocal and passive networks shows the effect of technologies such as News Feed. If these people were required to talk on the phone to each other, we might see something like the reciprocal network, where everyone is connected to a small number of individuals. Moving to an environment where everyone is passively engaged with each other, some event, such as a new baby or engagement can propagate very quickly through this highly connected network.

To get the full details on the Facebook Data Team’s approach and analysis, check out Marlow’s full post here.