Any adaptive organism faces the choice between taking actions with known benefits (exploitation), and sampling new actions to check for other, more valuable opportunities available (exploration). The latter involves information-seeking, a drive so fundamental to learning and long-term reward that it can reasonably be considered, through evolution or development, to have acquired its own value, independent of immediate reward. Similarly, behaviors that fail to yield information may have come to be associated with aversive experiences such as boredom, demotivation, and task disengagement. In accord with these suppositions, we propose that boredom reflects an adaptive signal for managing the exploration-exploitation tradeoff, in the service of optimizing information acquisition and long-term reward. We tested participants in three experiments, manipulating the information content in their immediate task environment, and showed that increased perceptions of boredom arise in environments in which there is little useful information, and that higher boredom correlates with higher exploration.