Essentials: Science of Stress, Testosterone, Aggression & Motivation | Dr. Robert Sapolsky

Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, I have the pleasure of introducing Dr. Robert Sapolsky. Thank you so much, Robert, for joining us today.

Oh, yes, glad to be here.

I wanna return to a topic that is near and dear to your heart, which is stress. What is the difference between short and long-term stress in terms of their benefits and their drawback? How should we conceptualize stress?

Basically, sorta two graphs that one would draw. The first one is just all sorts of beneficial effects of stress, short term, and then once we get into chronicity, it's just downhill from there. The sorts of chronic stressors that most people deal with are just undeniably in the chronic range, like having spent the last 20 years, daily traffic jams, or abusive boss, or some such thing. Um, the other curve that's sort of perpendicular to this is dealing with the fact that sometimes stress is a great thing. Um, like our goal is not to cure people of stress, um, because if it's the right kind, we love it. We, we pay good money to be stressed that way by a scary movie or rollercoaster ride. Um, what you wind up seeing is when it's the right amount of stress, it's what we call stimulation.

One thing that's really striking to me is how the, physiologically, the stress response looks so much like the excitement response to a positive event. But is there anything else that we know about the biology that reveals to us, you know, what, what really creates this thing we call valence, that an experience can be terrible or feel awful, or it can feel wonderful depending on this somewhat subjective feature we call valence?

On a really mechanical level, um, if you're in a circumstance that is requiring that your heart races and your, your breathing is fast and you're using your muscles and some such thing, um, you're gonna be having roughly the same brain activation profile, whether this is for something wonderful or something terrible, with the one exception being that if the amygdala is part of the activation, this is something that's gonna be counting as adverse. The amygdala, in some ways, is kind of the checkpoint as to whether we're talking about excitement or terror.

Let's use the amygdala as a transition point to another topic that you've spent, uh, many years working on and thinking about, which is testosterone and other sex steroid hormones. How should we think about the role of testosterone in the amygdala, given that the engagement of the amygdala is fundamental in this transition point between a exhilarating positive response and a, uh, and a negative stressful response? Or maybe just broadly, how should we think about testosterone and its effects on the brain?