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.

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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