Schadenfreude - enjoying the pain and failures of others - is an all-too-familiar feeling. It has perplexed philosophers and psychologists for centuries but, in a time of polarised politics, Twitter trolls and 'sidebars of shame', has never been more relevant. Recent studies have shown that we smile more at a rival's loss than at our own success. But why can it be so much fun to witness another's distress? And what, if anything, should we do about it? In this book, historian of emotions Tiffany Watt Smith offers expert insight and advice.