Why do people read negative Internet comments and do other things obviously painful? Because humans have an inherent need to     1    uncertainty according to a recent study in <em>Psychological Science</em>. The new research reveals that the need to know is so strong that people will     2    to satisfy their curiosity even when it is clear the answer will     3   
    In a series of four experiments, behavioral scientists at the University of Chicago Booth School of Business and the Wisconsin School of Business tested students' willingness to     4    themselves to unpleasant stimuli in an effort to satisfy curiosity. For one     5    , each participant was shown a pile of pens that the researcher claimed were from a previous experiment. The twist? Half of the pens would     6    an electric shock when clicked.
    Twenty-seven students were told which pens were electrified; another 27 were told only that some were electrified.     7    left alone in the room, the students who did not know which ones should shock them clicked more pens and incurred more jolts than the students who knew what would     8    . Subsequent experiments reproduced this effect with other stimuli,     9    the sound of fingernails on a chalkboard and photographs of disgusting insects.
    The drive to     10    is deeply rooted in humans, much the same as the basic drives for     11    or shelter, says Christopher Hsee of the University of Chicago, a co-author of the paper. Curiosity is often considered a good instinct—it can     12    new scientific advances, for instance—but sometimes such     13    can backfire. The insight that curiosity can drive you to do     14    things is a profound one.
    Unhealthy curiosity is possible to     15    , however. In a final experiment, participants who were encouraged to     16    how they would feel after viewing an unpleasant picture were less likely to     17    to see such an image. These results suggest that imagining the     18    of following through on one's curiosity ahead of time can help determine     19    it is worth the endeavor. "Thinking about long-term     20    is key to mitigating the possible negative effects of curiosity," Hsee says. In other words, don't read online comments.