"A single person watching videos eight hours a day (with no breaks or days off) would take more than 16 years to view all content posted only by the most popular channels on the platform during a week," added the study.
In other findings, 18% of the videos analyzed in the study referred to games in English. These videos were often longer than other content. Also videos with Tricks or "worst" received five times as many views as videos that did not mention those words.
Earlier this year, Wired reported how pedophiles used the comment section of YouTube videos with children to attract other predators.
Neither Pew Research Center nor YouTube respond immediately to a request for comments.