Why the rise of social media has given us a less happy, more polarized and dangerous world

In his 2010 book “The Shallows: What the Internet Is Doing to Our Brains,” Nicholas Carr argued that our immersion in digital media is rewiring the way we think, turning us into distracted skimmers who are losing the capacity for deep concentration.

Yet social media was in its infancy back then. His lament in those days was aimed at a panoply of online distractions such as email that needed to be written, blogs that cried out to be read, streaming videos, downloadable music — in other words, anything but the task at hand. He mentions Facebook, but only in passing. Over the years, I’ve sometimes wondered what he would make of the explosion not just of Facebook but of Instagram, TikTok and their ilk now that they’ve taken over so much of our lives.