Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, to find out what it can tell us about our innate capacity for change. In this episode, Kimberley and Xand examine the nipples – the least rude naughty bits! They hear from a nipple tattooist, explore why nipples are both milk dispensers and erogenous zones, and question why some nipples spark more outrage than others. Producer: Dan Hardoon Researcher: Emily Finch Executive Producer: Kate Holland A Whistledown Production for BBC Radio 4