Focusing on Twitter, the basic theme of the paper is that within any large social network, people tend to interact primarily within a small subset of more strongly connected, reciprocal relationships --which the authors refer to as “friends”. It’s hard to disagree with that basic premise, which we can readily observe in all our social networks, from the workplace to the neighborhood.
But, I have a lot of trouble with their conclusion. I don’t doubt “the existence of two different networks: a very dense one made up of followers and folowees, and a sparser and simpler [“hidden”] network of actual friends”. But then they assert that
most of the links declared within Twitter were meaningless from an interaction point of view. Thus, we need to find the hidden social network; the one that matters when trying to rely on word of mouth to spread an idea, a belief, or a trend. [emphasis added]The authors show lots of statistical associations, but I think it’s a big leap to assume that degree of “influence” necessarily resides within that “network of actual friends”.
It is particularly ironic that the authors cite Mark Granovetter’s groundbreaking 1973 article The Strength of Weak Ties (which Philly networking pioneer Stan Pokras introduced me to nearly 30 years ago, and which Wikipedia refers to as “one of the most influential sociology papers ever written”). My understanding of Granovetter is that he would regard these “networks of actual friends” as exhibiting “strong ties” among themselves, and that many of them also have “weak ties” with members of other “networks of actual friends”. His main thesis is that weak ties can have disproportionally strong influence because they help to bridge between otherwise unfamiliar networks.
In my own experience (admittedly without the statistical backup) new social networks like Twitter only validate and reinforce Granovetter’s insight that so-called “weak” ties can have unexpected “strength”:
- Some of the people I follow on Twitter are my favorite authors and thinkers, who don’t have any idea who I am (a weak tie). But they’ve influenced me greatly with some of the ideas and references to resources from their tweets.
- The authors don’t even mention “retweeting”, the fairly common practice of “forwarding” a tweet. People retweet posts specifically in order to bridge from one of one’s networks to another. (Retweeting has little value within one’s own “network of friends”.)
- Because of the profusion of hyperlinks within tweets, it’s really easy to follow-up on any weak-link tweet that seems even a little interesting, thereby enhancing their potential influence.