Social Media Is Harming Young People at a Scale Large Enough to Cause Changes at the Population Level

This is the nearly final version of our essay for World Happiness Report 2026. (There will be some minor proofreading and footnote changes). The World Happiness Report is published each March by the University of Oxford’s Wellbeing Research Centre in partnership with Gallup, the UN Sustainable Development Solutions Network, and an Editorial Board. It is a report on the state of well-being in more than 140 countries. Each year the editors pick a theme and invite several experts to write essays on that theme. In 2024 the theme was happiness at different stages of life, and the finding was that young people in Western countries are declining in well-being. For 2026 the theme is social media: was its global spread in the 2010s a major contributor to the declining well-being of the young in certain regions? We were invited to write a chapter and this is it, after revisions based on peer review. The editors graciously allowed us to post it online before the March 19 publication date so that discussion and debate on this topic can begin immediately.