Jonathan Bastian talks with Florence Williams, science writer and author of “Heartbreak: A Personal and Scientific Journey,” about the pain that comes with a breakup and why it’s so hard to move on. Later, Sandra Langeslag, associate professor of psychological sciences at the University of Missouri-St. Louis and Aimee Lutkin, writer, performer, and the author of “The Lonely Hunter: How Our Search for Love Is Broken: A Memoir,” discuss the cure for heartbreak and misconceptions about coupledom.