“…Being divorced is just about as heritable as schizophrenia, and you probably wouldn’t want to say that divorce is a genetic disease of the brain.”
By: Michelle Johnson (3/1/19)
Did you want to be a scientist when you were young?
I don’t think I’m somebody who really knew what I wanted to do when I was young. I was good at math and I guess thought I was going to be a mathematician—I was a math major which was fun for a couple of years, but math obviously gets super abstract. Once you get past there, you have to be really dedicated to it. So, probably like a lot of people over the years I became a psychology major. But even then, it’s not like I thought, “Oh, okay, now I want to be a psychologist.” I took my time growing up and got out of school and did a variety of things in my early twenties until I finally, I said, “I hate this job, I don’t want to do this forever. What should I do? Oh, I know—I’ll go back to graduate school.” Without really knowing what I was doing, I applied to graduate schools in clinical psychology, and I got into one program at the University of Texas. It was this wonderful kind of revelation when I got there. It was like for the first time in my adult life I loved doing something, and I was good at it.
What are some questions your research touches on?
My work is mostly about the genetics of the most complex human behavior—intelligence and personality and things like that. What’s characteristic of this kind of behavior genetics is that what you might think of as top-down is instead bottom-up. We don’t start at the bench with DNA and think, “Oh, what kind of effect does this DNA have on people?” It’s starts with, “Oh, we have personality measures on all these family members. How can we understand how they’re related?”
What has surprised you working in this field?
When people started studying this kind of behavior genetics, I think what the field thought was going to happen was that we’d find that some traits have a genetic basis and other traits don’t have a genetic basis, and we’re going to be able to say, “Maybe your IQ is more genetic, but your personality is more something that you learned.” To a surprising extent that never happened. But what has turned out is that pretty much any human individual difference you can think of is somewhat heritable. That’s true of things like intelligence and personality and schizophrenia and the things you’d expect, but it’s also true of marital status and how much television you watch and whether you’re a liberal or conservative.
I’ve spent most of my career wondering about what that means because that’s a finding that points in both directions: on the one hand it says the effect of our genes is very pervasive in everything that we are, but it also suggests that differences relating to genetics is not this special scientific finding. When people discovered that schizophrenia was heritable, people wanted to say, “Oh, well, it turns out that schizophrenia is a genetic disease of the brain.” But on the other hand, being divorced is just about as heritable as schizophrenia, and you probably wouldn’t want to say that divorce is a genetic disease of the brain. What’s really appeals to me about behavior genetics is that it’s as much a philosophical problem as it is an empirical one—the “nature-nurture” debate. Behavioral genetics is a way of bringing empirical data into the nature-nurture debate, but it turns out you can’t quite answer the questions that the nature nurture debate wants to answer using typical genetic data.
What’s the best piece of advice you’ve received?
My mentor in behavioral genetics, Irving Gottesman, he said to me, “You know, Eric this is a really, really hard job, and you don’t get paid all that much for it, and there’s a lot of disadvantages, so it isn’t worth doing unless you do exactly what you want and say exactly what you think.” I love being a professor. Academia is a great, it’s a great job. So, I like to think that I get to do what I want and say what I think.
To read more about Dr. Turkheimer and his work, click here