For those interested in sociological patterns within Facebook, Professor Jason Hoffman over at Harvard’s Berkman Center for Internet and Society has been running some tests on the same group of students over the last 4 years (about as longitudinal of a study as you’re going to get on Facebook at this point, given that the site is just over 4 years old) and has posted a video of his presentation here.

It’s about 50 minutes long, so here are some Cliff’s Notes that hit the highlights:

(via)