THE DARK PSYCHOLOGY OF SOCIAL NETWORKS: Why it feels like everything is going haywire. “At its inception, social media felt very different than it does today. Friendster, Myspace, and Facebook all appeared between 2002 and 2004, offering tools that helped users connect with friends. The sites encouraged people to post highly curated versions of their lives, but they offered no way to spark contagious outrage. This changed with a series of small steps, designed to improve user experience, that collectively altered the way news and anger spread through American society. In order to fix social media—and reduce its harm to democracy—we must try to understand this evolution.”

You could start here.