Q&A: Harvard Psychologist Joshua Greene

We chat with this prominent psychologist about everything from gut reactions and bachelor parties.


Greene studies the science of moral decision making. Moral decisions photo via Shutterstock.

Joshua Greene spends most of his time thinking about moral dilemmas. A psychology professor at Harvard University, his research focuses on the science and psychology behind moral behavior. He studies the ways we make decisions, mostly considering the differences between our gut reactions, which rely largely on emotions, versus our more thought out decisions.

Sound complicated? It is, but he says that much of his research boils down to just one question: Is it okay to push someone in front of a speeding trolley in order to stop the trolley from killing five other people down the tracks?

“The more I thought about this question, the more I wondered about the psychology behind it and, more specifically, the tension between emotion and reason,” Green says, explaining why he became interested in the topic in the first place. What’s he up to now? We sat down with him to find out about his new book and his favorite Boston pass times.

What are you up to these days?

I’m writing a book called “Moral Tribes: Emotion, Reason, and the Gap Between Us and Them”. It’s about understanding how moral thinking works and how it can work better, and how we can use a scientific understanding of ourselves to solve our problems, for political disagreements over things like gay marriage to global problems such as climate change. It will be out at the end of October. I’m also teaching and working on my own research. A lot of my work has to do with the tension between emotion and reason, between automatic gut reactions and more conscious, controlled thinking. My collaborators and I recently explored this tension in the context of religion and cooperation.

How did you initially become interested in the neuroscience of morality?

In high school, I was on the debate team, which introduced me to the foundational question of moral and political philosophy: How do you resolve the tension between the rights of the individual and the greater good?  This got me into philosophy, which introduced me to moral dilemmas. Then, as undergrad in 1995, I read a book by the neurologist Antonio Damasio, which described patients with emotion-related brain damage. Damasio said that they “know, but don’t feel”, and something clicked. I had the idea that the part of the brain that was damaged in these people played a critical role in our judgments about killing one to save five, like that question above and much more.

What implications does your research have on everyday life?

You can think of your brain as being like a camera with both automatic settings like portrait and landscape, as well as a manual mode. Your automatic settings are your emotional gut reactions. Your manual mode is your capacity for conscious reasoning. So, what’s better, automatic settings or manual mode? In photography, the answer is clear: Neither is absolutely better. Automatic settings are efficient, just point and shoot, but they aren’t very flexible. Manual mode is flexible, but not very efficient. They’re good for different things.

The same is true for emotion and reasoning. Our emotions give us good advice most of the time, but not always. And they’re especially bad when it comes to modern moral problems, which our brains just aren’t designed for. This comes up in bioethics all the time with issues like abortion and physician assisted suicide. It also comes up when we’re dealing with other groups of people that have different moral values, or that are just far away from us. To take a famous problem discussed by the philosopher Peter Singer: Do I have an obligation to help anonymous starving children on the other side of the world?

Your gut reaction may be that this is a nice thing to do, but that it’s morally optional. But is it morally optional to save a child who’s drowning right in front of you? I think our gut reactions may not be tuned in to the moral opportunities of the modern world. Our heartstrings are pullable, but often too short. I think we rely too much on our gut reactions, so that’s what I study.

What’s it like to study this stuff in Boston?

Boston is a fantastic place to be a philosophically minded scientist. With so many great universities in the area, it’s a Mecca for bold thinkers.

What do you do when you’re not researching, teaching or writing?

Free time? I wish! Between work and kids, I don’t get out much. My favorite thing, the one thing I regularly make time for, is running around Fresh Pond in Cambridge. And we love taking the kids to the Museum of Science. A colleague of mine recently had a low-key bachelor party and we took a sailboat ride around the harbor and had some manly beers and brats at Jacob Wirth downtown. I was like, ‘Look! There’s a whole city here!’ I’m going to try to visit the other side of the river more often.


Greene teaches a Harvard University psychology course. Photo provided.