The news site Upworthy has earned a reputation for engineering "curiosity gap" headlines—story titles that coerce a click through just the right balance of information and intrigue.
In posing a question or teasing readers with a potential a mystery, curiosity-gap headlines can be two or even three sentences long. Some feel like story leads in and of themselves. Exhibit A, from a Fall 2013 list of the site's greatest hits: "This Amazing Kid Just Died. What He Left Behind Is Wondtacular."
The media has criticized the approach for being repetitive and manipulative. (Reuters blogger Felix Salmon, calling curiosity-gap headlines "annoying," compared them to German sentences in that "you don't know what they mean until you get to the end.")
Yet those headlines are wildly effective. A recent web traffic chart reveals that Upworthy generated about 75,000 Facebook likes for each article. If that sounds impressive, get this: The second-best performing site generated fewer than 10,000 likes.
Whatever you think of Upworthy or Facebook traffic formulas (or the German language), the power of curiosity-gap headlines is, possibly, peerless. So what's the psychological reasoning behind our need to click?
After decades of research, behavioral scientists remain quite curious themselves about curiosity. A big reason the feeling is difficult to understand is because it runs counter to classical ideas about rational decision-making—we're invested in the belief that people choose to do something in order to fulfill a goal. This is why scientists are, well, a bit stumped. There's no clear extrinsic benefit or tangible utility to learning what the amazing kid who died left behind. But you clicked anyway.
Still, psychologists have some theories. The leading one, presented by George Loewenstein of Carnegie Mellon in the mid-1990s, is known as the "information-gap" theory. Loewenstein believes that curiosity proceeds in two basic steps: First, a situation reveals a painful gap in our knowledge (that's the headline), and then we feel an urge to fill this gap and ease that pain (that's the click).
"Such information gaps produce the feeling of deprivation labeled curiosity," wrote Loewenstein in Psychological Bulletin. "The curious individual is motivated to obtain the missing information to reduce or eliminate the feeling of deprivation."
That's simple enough. If we buy Loewenstein's theory, curiosity is not much different from other primal desires, such as those for food or sex. Its onset, like hunger or hunger, is acutely aversive. Its relief, like eating or copulating, is deeply satisfying (well, sometimes). The information-gap theory also posits that people should be most curious when they know what they don't know. (If you're too ignorant or too wise, you won't be very curious.) Loewenstein outlines five curiosity triggers that alert people to such a gap: questions or riddles, unknown resolutions, violated expectations, access to information known by others, and reminders of something forgotten.
Now go back to the list of top Upworthy headlines: Each aligns closely with one of these triggers.
Recent neural studies on curiosity support Loewenstein's information-gap theory. In one experiment, test participants had their brains scanned while they read a trivia question, guessed at the answer, and then saw it revealed. The research team (working with Loewenstein), found that curiosity activated the neural circuitry that's connected with rewards (including the left caudate region). Curious brains anticipated satisfaction from knowledge, just as a hungry stomach might pine for a meal. Or, you know.
The researchers also found evidence for what they call "inverted-U" behavior. That's the tendency of curiosity to be greatest at some mid-point between ignorance and wisdom—the peak of the inverted U. "The fact that curiosity increases with uncertainty (up to a point) suggests that a small amount of knowledge can pique curiosity and prime the hunger for knowledge, much as an olfactory or visual stimulus can prime a hunger for food," they concluded in a 2008 issue of Psychological Science.
A subsequent brain study, this one published in 2012, offered more nuance to the neural studies. After inducing curiosity in participants by showing them blurry images, researchers found brain activity related to conflict and arousal (in the anterior insula and anterior cingulate cortex). It was only when curiosity was relieved, by showing the clear image, that the reward circuitry seemed to come online. The findings, while a bit more complex, still support the idea that curiosity begins as a pain that the brain and body want to relieve.
Alternative theories exist. (One argues that curiosity must do more than simply ease a mental discomfort, because for some people the search itself is rewarding.) But the information-gap theory does the best job explaining why a curiosity headline can feel almost physically difficult to resist.
In an almost literal way, then, Upworthy is seducing your brain. Let's hope the headline was as good for you as it was for them.