Race is not a biological reality, but its toxic effects on society are plain to see: rising nationalism, simmering hatred, lost lives, and divisive discourse. Since genetics are difficult to grasp—and all too easy to distort—even well-intentioned people repeat stereotypes based on "science." But as the author of A Brief History of Everyone Who Ever Lived details here, the more researchers learn about who we are and where we come from, the clearer it becomes that our racial divides have nothing to do with observable genetic differences.