Whether we love them or hate them, think they're sexy or silly or strange, consider them too big, too small, or anywhere in between--humans have a complicated relationship with their butts. It is a body part unique to humans, and crucial to our evolution and survival--and yet, over time, it has come to represent so much more beyond its physiological function. A woman's butt, in particular, is forever being assessed, criticized, and objectified, the subject of crude remarks on the street or in a school hallway, or of anxious self-examinations in a dressing room mirror. But how did a mass of muscle and fat become an aesthetic and a cultural Rorschach test for our collective feelings about what's desirable, acceptable, and shameful? And why? In Butts: A Backstory, reporter, essayist, and Radiolab contributing editor Heather Radke is determined to find out. On a quest to explore the anatomical, emotional, and cultural ways that the butt has been understood throughout more than two hundred years of history, Radke takes us from the performance halls of nineteenth-century London and the aerobics studios of the 1980s to the music video set of Sir Mix-A-Lot's "Baby Got Back" and the mountains of Arizona, where every year humans and horses race in a feat of gluteal endurance. Along the way, she meets evolutionary biologists who study how butts first developed in early hominids, fit models whose measurements have defined jean sizing for millions of women, and exercise gurus who created fads like "Buns of Steel"; she also examines the central importance of race in our understanding of women's butts through figures such as Sarah Baartman--once known as the "Venus Hottentot"--Josephine Baker, Jennifer Lopez, and other women of color whose butts have been idolized, envied, and despised. Part deep-dive reportage, part personal journey, part cabinet of curiosities, Butts is an entertaining, illuminating, and thoughtful investigation of why certain silhouettes come in and out of fashion--and how larger ideas about race, control, liberation, and power affect our most private feelings about ourselves and others. -- From dust jacket.