Enlarge / Ooooh, I should share this on Facebook. (credit: Getty | Bert Hardy)

To figure out if a story will go viral on the Web, a crystal ball might seem useful. After all, any equation or formula to figure it out would have to account for some magical mix of a story’s qualities, quirky human preferences, and online habits—at least, that’s what you might expect. But, according to neuroscientists at the University of Pennsylvania, our brains might actually have a simple, generic calculation for it.

While perusing news stories, our brains gauge whether a story is interesting to ourselves, to others, and if sharing it could improve our standing or relationships, the researchers report. Then our wily noggins seem to use standard valuation machinery in the brain to essentially combine those assessments, score the story, and ultimately decide whether to share it or not. By monitoring those brain processes as people flipped through New York Times health articles, the researchers could better predict which stories actually went viral on the Web. Their results were published Monday in PNAS.

“It’s cool that the brain has developed this kind of specialized ability,” senior author, Emily Falk, director of Penn’s Communication Neuroscience Lab, told Ars. Psychologists might expect that if you simply provide health information to people in a logical way, that’s enough—people will have an objective understanding of its value. “But our data suggests that two of the really important inputs to ‘the value signal’ are these potentially holistic assessments of how self relevant and socially relevant information is.”