I interview Dr. Alma Gottlieb about what periods are, culturally – what they mean to us, what they do to us, how they fit or don’t fit into the dominant cultural paradigm. Dr. Gottlieb shares insights into menstrual taboos, in the United States and cross-culturally. She also talks about what it means that 20-25% of the reproductive-aged women you meet are menstruating, even though they are hiding it. What does it mean to hide something fundamental about yourself for a quarter of your lifespan from menarche to menopause?