For three months in late 2020, nearly 7,200 US adults on Facebook and 8,800 on Instagram received a radically different experience than the services’ billions of other users. When they scrolled through their newsfeeds, Facebook and Instagram showed them the newest posts as determined by the clock, not those judged most relevant by an algorithm. The response was clear: Users served chronological feeds got bored quicker and were much more likely to decamp to rivals such as YouTube and TikTok.That result emerged from a multimillion-dollar, Meta-backed science project designed to study how Facebook and Instagram affected people’s political attitudes during the 2020 US presidential election campaign. The experiment’s main purpose was to add empirical data to the ongoing debate about the role o...