This is, in essence, how all algorithms work. It’s how filter bubbles are made. A little bit of computer code tracks what you find engaging—what sorts of videos do you watch most often, and for the longest periods of time?—then sends you more of that kind of stuff. Viewed a certain way, YouTube Kids is offering programming that’s very specifically tailored to what children want to see. Kids are actually selecting it themselves, right down to the second they lose interest and choose to tap on something else. The YouTube app, in other words, is a giant reflection of what kids want. In this way, it opens a special kind of window into a child’s psyche.