YouTube videos that feature children under the age of 13 receive more than three times as many views as videos without children, a new study from the Pew Research Center found.

Pew assembled a list of popular YouTube channels (ones with more than 250,000 subscribers) that existed through late 2018, and it analyzed all of the videos that those channels produced during the first week of January 2019. While only a small number of English language videos were targeted at children, they still received more views on average than other videos that were not targeted at children. Any video that starred a child who appeared to be under the age of 13, however, “received nearly three times as many views on average as other types of videos.”

“The very small subset of videos that were directly aimed at a young audience and also featured a child under the age of 13 were more popular than any other type of content identified in this analysis as measured by view counts,” the report reads.

A YouTube spokesperson told The Verge that the company couldn’t “speak to Pew’s methodology or results,” adding that “generally on YouTube, the most popular video categories tend to be areas like comedy, music, sports and ‘how to.’” Still, including kids in videos to increase views is a facet of YouTube that many creators have picked up on. One of the largest family vlogging channels on YouTube, The Ace Family, amassed more than 16 million subscribers in less than three years, The Verge previously reported. Even Jake Paul, a vlogger known for his pranks, invited a family to live in his house so he could vlog with their four-year-old-son Tydus.

Creators have seen it as a way to guarantee ad revenue due to the videos’ popularity. Now, in wake of a Federal Trade Commission investigation into the safety of kids on the platform and reports of YouTube becoming a haven for predators, YouTube is trying to change part of its culture. The company has disabled comment sections on videos that feature kids, and it’s reportedly looking into algorithmic changes that could affect the videos that are being recommended.

YouTube’s current terms of service state that its platform is not intended for children under the age of 13. The company has developed an entirely separate app, YouTube Kids, that is supposed to be safer for young viewers.