Even though we still live in a big-boob bubble, more women are voluntarily reducing their breast size. Others are happily deciding to “go flat” after cancer. Trans women are learning how to lactate - are men next? Are we entering a post-boob universe, one in which we all take more control of what our individual breasts do and what they look like?

Retailers are now selling bras with princess characters on them. Girls are reaching puberty earlier than ever before. In this episode, we talk to some families and experts at the center of the quest to understand how modern life is changing breasts and what it means for our future.

In this episode, we talk to Chelsea Handler about her relationship with her large and well-publicized rack, and then find out what chemicals she has coursing through her bloodstream that might endanger her (and everyone’s) prized organs.

It can save babies’ lives and supply rarified fatty acids, antibodies and proteins. But breast milk also contains tons of mysterious sugars not digestible by babies. So, who are they for? And what can the answer teach us about the future of health and medicine, even for adults?

Mike Partain was born on a storied marine base in North Carolina. Thirty-nine years later, he was diagnosed with rare male breast cancer. Then he started finding old neighbors who were diagnosed, too. Thanks to these male outliers, scientists are learning more about what causes one of the deadliest women’s diseases in the world.

In modern-day America, we’re constantly bombarded with images of perfectly round, big, pneumatic knockers. Where did this ideal come from, and is it really everyone’s favorite boob type? Florence Williams administers the “Swami test” to find out which breast size most men prefer and tries to get to the bottom of some cherished, misguided myths.

Every mammal has mammary glands, but only humans have permanent, rounded, full-on breasts. Why? What are breasts really for, anyway? The answers matter, because they influence how we see each other and see ourselves. Florence Williams walks up the largest breasts in the world (they’re in England) and talks to Oxford’s Desmond Morris, author of the classic, The Naked Ape.

Florence Williams explores the history of a medical device that changed silhouettes around the world, and she finds the oldest living pair of silicone implants - in 84-year-old Texan Timmie Jean Lindsey, who has to decide whether or not to remove them for the sake of posterity and a museum. “It’s my luck, they’ll get lost in the mail,” says Lindsey.

Breasts have been bared, flaunted, measured, inflated, suckled, pierced, tassled -- and in every way fetishized by our society. Host and science journalist Florence Williams (prize-winning author of BREASTS: A Natural and Unnatural History) delves deeper into the mysteries of the human breast with funny and enlightening reporting. She tackles the big questions of why they evolved in the first place, how jet fuel ended up in breast milk, why they are arriving earlier and bigger in teen-aged girls, man boobs, and how breast cancer in men can help female breast cancer patients. Coming December 5, 2017 to Apple Podcasts and wherever else you listen, and available NOW on Audible.