Estimates put the percentage of the world's inhabitants who are on social media at 59%. Whether that seems high or low might reveal something about your own habits. In "The Chaos Machine," New York Times investigative reporter Max Fisher aims to reveal exactly what's happening under the hood.

What he calls the "largest town square in human history" has many positive, or at least benign, functions — from connecting family members and promoting businesses to providing lifesaving information in crises. But as anyone who has read about (or been a target of) "pitchfork nation" can attest, the dark underside of social media can be very dark indeed.

Fisher's exhaustively documented book reminds us of Gamergate, Pizzagate and the Twin Cities dentist who killed a lion, instances in which rumors were spread as gospel to the extent that careers and lives were ruined. He delves into the doom-loop of polarization and misinformation that he asserts led to the election of Donald Trump and the deep divisions over COVID-19. Perhaps most devastatingly he details the role of social media in deadly uprisings in Myanmar and Sri Lanka. He emphasizes that the underlying issues had always been there, but social media "exacerbated them all, in some cases drastically."

Nearly all the major players make an appearance, but Fisher reserves special ire for YouTube and Facebook. He takes us on a tour of the companies' moral grandstanding and halfhearted soul-searching after an election or a massacre (followed by a doubling down). You might find yourself wondering how Mark Zuckerberg sleeps at night.

Published in September 2022, Fisher's book just predated Elon Musk's purchase of Twitter. I foresee a sequel just to examine that dumpster fire.

Cynthia Dickison is a designer at the Star Tribune.

The Chaos Machine: The Inside Story of How Social Media Rewired Our Minds and Our World

By: Max Fisher.

Publisher: Little, Brown, 400 pages, $23.49.