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, determine 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 that it 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 also explains how our behaviors and perceptions shape testosterone levels. And we 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 if we have any free will, including how knowledge alone might allow us to make better decisions for ourselves and society. Read the full show notes for this episode at hubermanlab.com.Thank you to our sponsorsAG1: https://athleticgreens.com/hubermanLMNT: https://drinklmnt.com/hubermanlabWaking Up: https://wakingup.com/hubermanMomentous: https://livemomentous.com/hubermanTimestamps00:00:00 Introduction: Dr. Robert Sapolsky  00:02:25 Sponsors: AG1, LMNT & Waking Up00:06:30 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  Disclaimer & Disclosures Learn more about your ad choices. Visit megaphone.fm/adchoices