Here’s a bit of science that’s contrary to what a heavy utilizer of social networks might expect. Researchers at Harvard tracked the Facebook activity of hundreds of college students for four years, and came away with the rather unexpected result that the interests of friends don’t, in fact, tend to influence one another. That’s not to say it doesn’t happen at all, of course, but it’s clear that propagation and virality are subtler and more complex than some people (marketers and, I suspect, researchers) tend to think they are.

But the study is also clearly flawed in ways that those versed in social graphs are likely to easily perceive. Pulling useful data from social networks is like catching lightning in a bottle, and I wonder whether the findings may in fact be, as the study attempts to avoid, “a spurious consequence of alternative social processes.”

The central source of data for the study, in fact, doesn’t strike me as solid. Tracking the interests of college kids is a sketchy endeavor in and of itself, but tracking it via their Facebook favorites (i.e. what shows on your profile, not what you post about or share) seems unreliable.

After all, not only does everyone use the network in their own way, but the network itself has changed. Putting Wilco in your favorites is a different act from liking Wilco’s Facebook page, their official band site, or posting their latest video. Gauging someone’s interest in a movie or band by the favorites factor alone is inadequate. Their findings are essentially that taste doesn’t diffuse the way you might expect. But while the data support this, nothing supports the data.

Flattening huge sets of data and removing potentially conflative or distracting connections (“disentangling,” to use the researchers’ well-chosen word) is the bane of social research, and with a limited window on a huge field of data, like that these researchers had, it’s especially