Dr. Robert Sapolsky: Science of Stress, Testosterone & Free Will | Episode 35

Almost everybody out there has a completely wrong idea as to what testosterone does, which is testosterone makes you aggressive ... The easy thing, then, tends to conclude that testosterone causes aggression, and the reality is testosterone does no such thing; it doesn't cause aggression.

My personal, way out in left field, inflammatory stance is I don't think we have a shred of free will. Despite 95% of philosophers and, I think, probably the majority of neuroscientists saying that we have free will in at least some circumstances, I don't think there's any at all.

I think it's a fair summary to think that when it comes to motivated, strong behaviors, what testosterone does is make you more of whatever you already are in that domain—sexual arousal, libido, aggressiveness, spontaneous aggression, reactive aggression, things of that sort; it's upping the volume of things that are already strongly there.

The stress management-type techniques that work, you can't save them for the weekend. You can't save them for when you're stuck on hold on the phone with music for two minutes. It's got to be something where you stop what you're doing and do it virtually daily or every other day and spend 20-30 minutes doing it.

Not only can, say, prenatal hormone exposure change the way your brain is being constructed, but learning that prenatal hormone exposure can change the construction of your brain will change your brain right now and how you think about where your intentions came from ... The knowledge of the knowledge is an effect in and of itself.

About 20 years ago, [John Wingfield] formulated what was called 'The Challenge Hypothesis of Testosterone Action.' What does testosterone do? Testosterone is what you secrete when your status is being challenged, and it makes it more likely that you'll do the behaviors needed to hold on to your status.

Estrogen, in lots of ways, could be summarized by: If you had a choice in the matter between having a lot of estrogen in your bloodstream or not, go for having a lot of estrogen. It enhances cognition... It stimulates neurogenesis in the hippocampus. It increases glucose and oxygen delivery. It protects you from dementia. It decreases inflammatory oxidative damage to blood vessels, which is why it's good for protecting from cardiovascular disease...

Do not trust anybody who says it has been scientifically proven that their brand of stress management works better than the other ones. Just watch your wallet at that point.

If you're in a circumstance that is requiring that your heart races and your breathing is fast and you're using your muscles... you're going to 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 going to be counting as adverse.

Do you have a sense of control? A sense of control makes stressors less stressful.