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Interview with Paul Rozin

Behavioural Science is a rapidly expanding field and everyday new research is being developed in academia, tested and implemented by practitioners in financial organisations, development agencies, government ‘nudge’ units and more. This interview is part of a series interviewing prominent people in the field. And in today's interview the answers are provided by Paul Rozin. Paul is a professor of psychology at the University of Pennsylvania. He teaches two Benjamin Franklin Scholars (BFS) honors courses and graduate level seminars. He is described as the world's leading expert on disgust. His work focuses on the psychological, cultural, and biological determinants of human food choice. His teaching and research interests include: acquisition of likes and dislikes for foods, nature and development of the magical belief in contagion, cultural evolution of disgust, ambivalence to animal foods, lay conception of risk of infection and toxic effects of foods, interaction of moral and health factors in concerns about risks, relation between people's desires to have desires and their actual desires (including the problem of internalization), acquisition of culture, nature of cuisine and cultural evolution, and psychological responses to recycled water.


Who or what got you into behavioural science? I got into behavioural science in a sort of an indirect path. As an undergraduate, I thought I would be a nuclear physicist. But before you get into physics, you have to do some math. So I got started studying actual physics in my third year of college, and I couldn't deal with it. It was a very, very odd physics course, very mathematically oriented and very fast-paced. The idea was (this was at the University of Chicago, a big physics school) to get people to stop majoring in physics, so they gave this really hard course. And I just couldn't keep up with it. It started out with mechanics, which is something I have no intuition for. So I eventually dropped the course. And I decided, well, I wasn't going to be a physicist. But I did love math, so I thought I would become a mathematician. I took some math courses, and I did well in them. But there was one person in the math class of mine, who was an order of magnitude better than I was. He was just so much better than I was, I couldn't stand it. And I decided I couldn't be in the field that he was in, because he could do in a few minutes anything I could do in a month in a day. So I decided to look for another field. And I tried out different fields. And I took a psychology course, on learning. And I really liked it. So I took a bunch of psych classes in my senior year, and decided I wanted to go into psychology, behavioural sciences. I loved the psychology classes. They were all classes in experimental psychology, learning, perception, etc. So I went to graduate school at Harvard for psychology. And pretty quickly, I realized that I was more interested in the biological side of behavioral sciences. So I ended up taking a joint PhD in biology and psychology. I also took a good part of first year medical school, so I got a strong background in biology and some neurology particularly. After all that I started out as a psychology professor, my first job at University of Pennsylvania, and I stayed there for my entire life. I started out as very much a biological psychologist. But as I worked more and more, I got interested in food as a focus of research. I then realized that the biggest determinants of human food choice are cultural, so I actually shifted over to become a cultural psychologist, with anthropology linking in more than biology, so that's how I got to where I am.

What is the accomplishment you are proudest of as a behavioural scientist? And what do you still want to achieve? One of the things about my career is I never knew what I'd be doing in five years. Most really good people start on a problem and stick with it for most of their life. I didn’t and still don't do that. So I don't know what I'll be doing in five years. What I like to do is to get involved in one or more interesting new problems. I like to start fields, I like to get people interested in something that they weren't interested in before. So probably my greatest success was with disgust, I started studying the emotion of disgust in the 1980s. And there was virtually no literature on it. All literature on emotion focussed on anger, joy, fear and sadness. So I started working on disgust and showing that it was a really interesting emotion. And it became a major focus of research in psychology, and then also became an important area in cognitive neuroscience. don't do much of it anymore, because I don't like to be in crowded fields. So I got out of it. But I really started something there. I've started other areas of research, , but disgust was the biggest one probably.

If you weren’t a behavioural scientist, what would you be doing? Well, I love the academic world. I've been so happy being in it, dealing with other professors and students; and I love to teach. So my guess is I would still be an academic, but in some other field such as anthropology or archaeology. Or maybe some aspect of cellular biology, I'm really not sure.

How do you apply behavioural science in your personal life? I do apply behavioural science in my life. First of all, my work has taken me into the area of food and health, so I got some background in that,t, but I'm not really an expert on food and health. But I'm interested in how people get crazy ideas about what's healthy and what's not. Like the idea now of “natural” being healthy. There's no evidence for that. More generally, I use the knowledge I have of both how people think about risks, and what they know about food in the food world to guide my own life and food choice. And, you know, I'm very interested in decision psychology. I'm aware of how I make decisions more than most people would be, and how much of a role my intuitions play and so on. So yes, it does influence my life.

With all your experience, what skills would you say are needed to be a behavioural scientist? Are there any recommendations you would make? Well, for me, the most important thing is to find something that is unstudied , but really interesting. It's got to do with having an open mind looking at the world in a certain way. For example, I had a friend who was a Holocaust survivor. she spent two years in Auschwitz as a young girl. And what I was fascinated by was that she had not become anti-German. She was still happy to sing German Lieder and had no problem with going to Germany. And I thought that was amazing, because I knew American Jews, who had nothing to do with the Holocaust who wouldn’t even buy a Volkswagen. So how could she have had this terribly traumatic experience, and come out not being anti-German? So that led me to do a study of Holocaust survivors. And we indeed found that a small subset of them, but certainly a minority, that are not anti-German. And then we start to ask “how do you come out of the Holocaust, not being anti-German (they do come out anti-Nazi)? So the point is, I saw something in the world, that I couldn’t figure out. It helps if you know enough psychology to know that psychology may have a chance to explain it. And then take it from there. How do you think behavioural science will develop (in the next 10 years)? Well, people can't predict these things. People are very bad at predicting. But I’ll try. I think the interest in the brain right now will persist for a while, because there's a lot of technology coming making it easier to study the brain. The big break there was being able to see what's going on in the brain without actually going in. This is going to remain a major part of psychology, but less than it is currently Now, I think that there's going to be more and more interested in social psychology, because that's where behavioural science touches on the world's problems: ethnic conflict, violence, etc. And the behavioural science isn't as well developed there. But we don't yet have anything equivalent to brain scanning, that will make it much easier to doresearch. But I think in the long run, that's going to be an area of importance, but I can't predict the timing of it.

What advice would you give to young behavioural scientists or those looking to progress into the field? Behavioural science is a very appealing area. But it runs all the way from doing mathematical modelling to watching people or animals, and just try ingto make sense of what they do, which is a very different kind of thing. You can study almost everything, and call it behavioural science: anthropology, political science, sociology. You can't study physics, and call it behavioural science, but you can study physicists, and how they deal with their work.

I see two very different ways of going into the field. One is to go into some area that's really exciting. Like, for example, brain imaging, as a way of getting insight into the mind and behavior.. There's a lot of new technology there, there's grant money for it and there's a lot of prestige associated with it. So, loads of people are doing it. The field is getting full. Personally, I wouldn't touch it; there’ are too many good people doing it, it's very competitive. I prefer to work in an area, which is less populated, less popular, where very basic work still needs to be done. And there's a lot of basic work still to be done in behavioural science. We just did a study on how important clothing is when people size other people up. What you're wearing is something you can control and it will make an impact. There’s almost no literature on this. You're starting from the very basic things; you don't have a lot of people who are competing with you, and you can make a lot more progress in a way. On the other hand, you don’t have many colleagues, and it's very hard to get money to study something that nobody is studying. It's a big choice to make as to whether you want to go with the crowd. After that, think about something you would love to study for years and years.

Which other behavioural scientists would you love to read an interview by? Kurt Richter and Solomon Asch have been two big inspirations for me. As a third I’d nominate Richard Shweder, who is the founder of cultural psychology. Other people who I think will have interesting things to say about behavioural science will be Paul Bloom; he just does interesting things. He works on the development of language, but he gets involved in all sorts of things. Another very interesting person is a former student of mine, Jonathan Haidt, who is now in the public sphere. Last, and a little atypical of the neuro people now, is Morris Moscovitch; he realizes the importance of behavioural science. Many people who study the nervous system consider psychologists just a nuisance, but he has a completely different perspective and should be interesting for you to talk to or read..


Thank you so much for taking the time to answer my questions Paul!

As I said before, this interview is part of a larger series which can also be found here on the blog. Make sure you don't miss any of those, nor any of the upcoming interviews!

Keep your eye on Money on the Mind!



This is the biggest inspiration in the field. I would also say that Paul Rozin has been a big influence on me. Nice conversation!


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