Biology Professor Robert Sapolsky teaches the wildly popular class “Human Behavioral Biology,” offered every other spring. The class is a Stanford institution in the same league as Dr. Dement’s “Sleep and Dreams,” and fire evacuation codes forced the Biology department to cap the class at 600 students this quarter. Prof. Sapolsky is a recipient of the MacArthur Fellowship “genius grant” and the author of several popular books, including “Why Zebras Don’t Get Ulcers: An Updated Guide to Stress, Stress-Related Diseases and Coping” and the autobiographical “A Primate’s Memoir.”

The Stanford Daily sat down with Prof. Sapolsky to talk about baboons, the death penalty and his trademark facial hair.

SD: I read in “A Primate’s Memoir” that, as a kid, you had decided to be a mountain gorilla when you grew up. How did you switch career paths to become a Stanford professor?

RS: [laughs] Well, some reality crept in at some point... I will take [the question] on two levels: first, how did I go from wanting to study mountain gorillas to actually studying baboons? That was because of the science I wanted to be doing, such as darting animals, and taking blood — you are not going to be doing physiology on mountain gorillas.

SD: Because they’re endangered?

RS: They’re endangered and they’re big! ...Not much is known about their physiology. And they’re up in rain forests, so it’s too dark to see them. It’s just not practical...

The other part of your question is how I shifted from just primatology to primatology and neurobiology. I went to college to study very specifically from this one primatologist — who actually turned out to be a huge disappointment; anyway, my freshman year he had a very mild heart attack. He’s still around and he’s fine, but that year, he cancelled all his classes. Those were three of the classes I was going to take, so I had to schedule others. Somewhat randomly, I ended up taking this introduction to neurobiology class, and I decided that it was much more interesting to think about behavior in the context of the brain than behavior in the context of ecology and evolution.

SD: Do you go to Africa anymore?

RS: I was there last summer, for the first time in three years.

SD: What did you research while you were there?

RS: We’re looking into if there are rank-related and personality-related [differences] in the baboons concerning their neurochemistry of anxiety....Essentially, if you are a low-ranking baboon... you’ve got a hell of a lot of things in your life to be anxious about on a regular basis, so you gear up your benzodiazepine system like crazy because you’re in for it, big-time [benzodiazepines are natural neurochemicals that are similar to valium].

SD: How do you have time to do it all? You teach, you do research, you write books — do you have a family, too?

RS: Yeah, I have two kids...I don’t sleep much.

SD: How old are your kids?

RS: Nine and 11. We just took them to Africa for the first time, which was very anxiety-provoking and very spectacular.

SD: What do they think of Africa?

RS: Well, they have very different temperaments. My 11-year-old son is considerably more cautious than my daughter, so he could recite a long list of every single tropical parasite within a 500-mile radius...But my daughter is this extreme free spirit.

SD: Did they get to see the baboons up close?

RS: Yeah, they helped with darting, and my daughter did a small and very unsuccessful experiment to see whether all baboons had fingerprints that were different. That consisted of her taking out her marker pens that we brought for her to do, like, coloring books, and taking the marker to the baboon’s finger and pressing and smudging it, and then the next day taking a different baboon and smudging that one’s fingerprint...They were two different smudges so, based on that, she announced that no two baboons on Earth had the same fingerprint. That was her contribution to primatology.

SD: That’s a good start.

RS: Um...yeah. One more fingerprint and she could publish!

SD: A friend of mine who’s taking your class right now mentioned that you’ve testified in court.

RS: Yeah, I worked with the San Diego public defender’s office in a death penalty case. This guy had just been convicted of his eighth and ninth murders...with awful details beyond imagination. The defense consisted of him standing up for 30 seconds and saying yes, he did it...It was now in the death penalty phase: to see if he would get that, or life without parole. The key issue with this guy was that he’d had a major car accident when he was eight that did enormous amounts of damage to his frontal lobe. He was in a coma for a month afterward...He had no prior history of antisocial behavior, no family history...If I’m remembering right, he had his first violent assault by the time he was 11, and his first murder after that...The guy was just a broken machine. They basically gave me a day in front of the jury to teach them how the brain works, starting with one neuron up to the frontal cortex. I was what they call a teaching witness...I was not discussing anything about the defendant specifically. I had not read anything beyond the most superficial summaries of the case. It was all to get [the jury] to the point of thinking of the cortex and us as biological organisms. The next day they could bring in the clinicians with his brain scans to say “Remember the frontal cortex? You see this big gaping hole? That’s where this guy’s should be.” It was so disturbing thinking about this guy and seeing him in the room, while at the same time feeling intellectually that it was absolutely clear which side should be argued.

SD: So what happened?

RS: The first time around, 11 jurors were for death. There was one incredibly brave holdout, so it got called a mistrial. And then we had to do it all over again with a new jury. The second time around, it took them about half a day to give him the death penalty. And so, it didn’t work! That was about five years ago now.

SD: Wow.

RS: It was pretty intense. It was a very strange experience.

SD: On a lighter note, I was wondering how long you’ve been sporting your signature facial hair.

RS: I’ve never actually shaved in my life. I decided somewhere along the way I wasn’t going to. My parents were absolutely miserable when I was 15, and I had these random patches of hair on my face.

SD: Do you trim your beard?

RS: [laughs] Every now and then.