How Hormones Shape Sexual Development

In this episode, I discuss how hormones such as testosterone and estrogen and their derivatives impact the early development of the brain and body and their maturation. I review published data on environmental factors shown to powerfully alter hormone pathways in animals and humans and the effects of cannabis, alcohol and cell phones on testes, sperm, ovaries and hormones. I describe the predictable relationship between genes, beard growth and balding patterns, and the importance of estrogen for brain development in people of all chromosomal sexes. Finally, I discuss how the hormones we are exposed to in the womb shape the relative length of our finger digits, the sounds our ears make (yes you read that correctly), and how those correlate with people's self-reports of their sexual preferences. As always, basic information and tools are discussed. Read the full show notes for this episode at hubermanlab.com. Thank you to our sponsors AG1: https://athleticgreens.com/huberman LMNT: https://drinklmnt.com/hubermanlab Waking Up: https://www.wakingup.com/huberman Timestamps 00:00:00 Introduction 00:00:30 AG1, LMNT & Waking Up 00:06:47 Announcement: Mood Meter App Works Again 00:08:00 Maximizing Learning from the Podcast 00:10:00 New Non-Sleep Deep Rest Protocol, Spanish Subtitles 00:11:35 Sexual Differentiation: Hormones, Neurons & Behavior 00:14:15 Hormones Basics 00:15:26 Sperm Meets Egg, Chromosomal Sex, Gonadal Sex 00:17:50 Y Chromosome Inhibition of Feminization 00:19:00 Placenta Is An Endocrine (Hormone-Producing) Organ, Adrenal Testosterone 00:19:45 Hormonal Sex, Morphological Sex 00:21:04 Hormones Fast & Slow, Sex Steroids Can Turn On Genes 00:23:06 Masculinization, Feminization, Demasculinization, Defeminization 00:23:42 Primary Sexual Characteristics: DHT Drives Penis Development 00:27:03 Secondary Sexual Characteristics 00:27:43 Penis Sprouting: Guevedoces 00:31:25 Estrogen, NOT Testosterone, Masculinizes The Brain 00:33:15 Breast Development In Males: Aromatase; Puberty, & Steroids in Athletes 00:34:50 Estrogen Powerfully Controls Brain Development In All Individuals 00:35:19 Avoiding Hormonal Disruption In Children & Adults: Specific Oils, Creams, Etc. 00:39:00 Environmental Endocrine Disruptors, Sperm Count Decline, Vincloziline 00:44:20 Androgen Insensitivity Syndrome: Hormones Need Receptors, SARMS 00:48:41 Estrogen Establishes “Masculine” Brain Circuits, Testosterone 00:49:42 Cannabis, Alcohol: In Babies, Puberty & Adults 00:56:25 Cell Phone Technology: Effects On Hormones, Ovaries, & Testicles 01:02:33 Beards & Baldness Patterns Around the World, DHT, 5-alpha-reductase 01:06:39 Creatine & DHT/Hair Loss 01:08:20 Predicting Aging Rates By Pubertal Rates 01:10:04 Hyenas, Baseball, & Jumbo Clitorises: Androstenedione 01:14:26 Intersex Moles 01:15:40 Marijuana Plants, Pollens: Plant-To-Animal “Warfare” 01:20:08 Finger Length Ratios, Prenatal Hormone Exposure & Sexual Orientation 01:29:13 Brain Dimorphisms with Sexual Orientation 01:32:00 “Older Brother Effects”: Male Fetuses Might Change Mothers & Subsequent Brothers 01:35:06 The Path Forward & A Warning 01:35:55 Support & Your Questions Disclaimer & Disclosures Learn more about your ad choices. Visit megaphone.fm/adchoices