Autoplay spread because apps had to steal time from each other

You never asked for videos to start playing by themselves. They started because your attention is scarce and worth capturing.

That is the account of Tristan Harris, a former Google design ethicist who studied how to steer thoughts ethically. When you check your phone, the way the feed is designed does something concrete to your day: "it's scheduling little blocks of time in our minds." A notification steers you toward a thought you did not plan to have. A swipe steers you into time spent on something you did not plan to open.

The driver is a hidden goal shaping "all of the technology we make," the race for our attention. Every news site, game, politician, and even meditation app competes for the same limited supply, and there is only so much of it. An effective way to win is to understand how the mind works. Many of the methods in play are persuasive techniques he picked up as a student at the Persuasive Technology Lab.

Autoplay shows the copying in action. YouTube wants to hold viewers longer, so it starts the next video on its own. That approach works really well and gains a little more of people's time. Netflix treats that gain as shrinking its market share, so it starts the next episode on its own. Facebook treats that loss as shrinking its share, so it starts every clip in the feed on its own without waiting for a tap.

The result is not random, and technology is not neutral. Each step lowers the bar for keeping people watching. His shorthand for that direction is "race to the bottom of the brain stem."