Science of Stress, Testosterone & Free Will | Dr. Robert Sapolsky

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.

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Timestamps

00:00:00 Introduction: Dr. Robert Sapolsky

00:02:25 Sponsors: AG1, LMNT & Waking Up

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”