Infants look longer at events that are unexpected (e.g. a ball floating in midair) and at events that are different from what they have previously seen (e.g. rightward motion, after repeated exposure to leftward motion). This has led to debate about whether shared or distinct mechanisms lead infants to look longer toward unexpected events (the violation-of-expectation response, or VOE) versus visually novel events (the perceptual novelty response, or PN). Here, we studied both looking behaviors using meta-analysis of condition-level data (from 34 papers, 78 conditions, and 1915 infants) and mega-analysis of infant-level data (from 25 papers, 60 conditions, and 1482 infants) from prior studies of infants’ understanding of agents and objects. First, we estimated VOE and PN in the same data and found that showing infants an unexpected event drove their looking behavior as reliably as showing infants a visually novel event. Second, we tested whether VOE and PN are supported by similar or distinct mechanisms. Under the hypothesis that both responses are driven by a common mechanism, the same factors should predict the size of both effects. However, these responses were moderated by different predictors. The PN effect was larger after infants were habituated instead of familiarized, and did not differ depending on infant age. The VOE effect, in contrast, was not moderated by habituation vs familiarization and was larger for younger infants. These findings suggest that these two responses reflect distinct drivers of infant visual attention