In this episode, I interview Dr. Robert Sapolsky, Ph.D., Professor of Biology, Neurology & Neurosurgery at Stanford University. We discuss stress, what defines short-term versus long-term stress and how stress can be beneficial or detrimental depending on the context. We also discuss stress mitigation and how our sense of control over stress-mitigation techniques, including exercise, determines health outcomes. Dr. Sapolsky explains some of the key effects of the hormone testosterone—how it can amplify pre-existing tendencies for aggression or sexual behavior but does not produce those behaviors per se. He also explains how testosterone impacts our social hierarchies, sense of confidence and willingness to embrace challenges of different kinds. He further explains how our behaviors and perceptions shape testosterone levels. We also discuss estrogen and the powerful role it plays in brain development, health and longevity. Finally, we discuss free will, what it means to have free will and whether we have any, including how knowledge alone might allow us to make better decisions for ourselves and society. For an up-to-date list of our current sponsors, please visit our website: https://www.hubermanlab.com/sponsors. Previous sponsors mentioned in this podcast episode may no longer be affiliated with us. Social & Website Instagram: https://www.instagram.com/hubermanlab Threads: https://www.threads.net/@hubermanlab Twitter: https://twitter.com/hubermanlab Facebook: https://www.facebook.com/hubermanlab TikTok: https://www.tiktok.com/@hubermanlab Website: https://www.hubermanlab.com Newsletter: https://www.hubermanlab.com/newsletter Apple Podcasts: https://apple.co/3thCToZ Spotify: https://spoti.fi/3PYzuFs Links Dr. Sapolsky's most recent book, "Behave: The Biology of Humans At Our Best & Worst": https://amzn.to/3yrZ6k7 Support Research in the Huberman Lab at Stanford on Stress, Sleep & Human Performance: https://hubermanlab.stanford.edu/giving Timestamps 00:00:00 Introduction: Dr. Robert Sapolsky 00:02:26 Sponsors: Roka, InsideTracker 00:06:30 Stress: Short & Long-Term, Good & Bad 00:09:11 Valence & Amygdala 00:11:00 Testosterone: Common Myths vs. Actual Truths 00:15:15 Behaviors that Affect Testosterone 00:17:20 Mindsets & Contexts that Affect Testosterone 00:20:28 How Finger Length Ratios Reflect Prenatal Hormone Levels 00:22:30 Aggression: Male-Female, Female-Male, & Female-Female 00:24:05 Testosterone: The Challenge Hypothesis 00:29:20 How Dopamine Impacts Testosterone & Motivation 00:32:32 Estrogen: Improves Brain & Longevity BUT TIMING IS KEY 00:39:40 Are Testosterone & Sperm Counts in Males Really Dropping? 00:42:15 Stress Mitigation & Our Sense of Control 00:51:35 How Best to Buffer Stress 00:57:04 Power of Perception, Choice & Individual Differences 01:00:32 Context-Setting, Prefrontal Cortex & Hierarchy 01:11:20 How Dr. Sapolsky Accomplishes Deep Thinking 01:13:17 Do We Have Free Will? 01:20:50 How to Apply Knowledge & Learning 01:23:44 Robert’s New Book: “Determined: The Science of Life Without Free Will” 01:28:27 Reflections, Support of Podcast, & Supporting Stress Research Photo credit: Linda A. Cicero (used with permission from Stanford Medicine Media) Disclaimer: https://www.hubermanlab.com/disclaimer