I was pointed to an interesting paper called "Social Transmission and Viral Culture" (PDF) by an article in the NY Times. Wharton researchers Berger and Milkman looked at most shared articles on the nytimes site, coded them for qualitative properties such as awe, surprise, and valence, and controlled for other properties such as topic area and location of article placement. They found that more awe-inspiring, surprising, useful, and positive articles were more likely to be shared or become viral. The element of awe seemed to be particularly influential.
Ok, so it is focusing on a potentially skewed demographic (readers of a single publication who share stories online) and the intercoder reliability was only in the 75% range, a little low but probably ok for an exploratory study. But overall it's a well-done study with a lot of potential future directions and implications for news readers and news reporters alike.
What's really cool about this work is that, if shown to be more generally applicable, it could have influences on how news is reported, what news is emphasized, and how it is presented to us. I for one would welcome news with a more positive or useful slant that potentially strengthens my understanding of things beyond, well, me.
Moreover, this provides an additional glimpse into the psychological properties of what we share and potentially why we share it, something to add to the already-extensive literature on gift-giving and storytelling and the more recent work in online media sharing.