New Podcast Release: Josh Greene

In the latest episode of Lives Well Lived, the podcast I co-host with Kasia de Lazari-Radek, we speak with moral psychologist, philosopher, and author Josh Greene.

Josh’s career has bridged the worlds of neuroscience, ethics, and behavioural science. Best known for his work on moral judgement and his influential book Moral Tribes, he has spent decades exploring how human psychology shapes our moral decisions and what that means for creating a better world.

In this conversation, we explore how Josh’s thinking has evolved from an early hope that better understanding our psychology could lead to better moral philosophy, to a more practical turn toward interventions that measurably reduce suffering. We discuss two of his current projects: Giving Multiplier, which nudges people to support more effective charities, and Tango, a quiz game designed to reduce political polarisation.

Josh also reflects on moral progress, why he remains hopeful despite increasing division, and what it means to live well in a world full of moral complexity.

Below are some highlights from our conversation, edited for clarity. You can listen to the full episode on Apple Podcasts, Spotify, or your preferred platform.

Hope in an Age of Division

KASIA DELAZARI RADEK: Josh, it feels like we are living in a time of moral chaos in both your country and mine - the US and Poland. Political divisions are deeper than ever, and social media seems to turn every disagreement into a tribal war. The hatred and moral outrage online aren't just polarising here in Poland. It's really destructive, and I think it is in the United States as well and probably in other parts of the world. You've written that "our moral brains evolved for cooperation within groups, not between them," but if that's true, do you see any hope? For us? For our countries? Can reason really compete with outrage, or are we just too emotionally wired to go beyond our tribes?

JOSH GREENE: Yeah, those are the big questions. And thanks so much for giving me a chance to think with you and talk about it. I do hold out much hope. The reason is that what counts as "us," what counts as a group, is by no means hardwired from an evolutionary point of view. In fact, humans have historically used cultural markers to determine who's in and who's out. The people on the other side of the hill or the river wouldn't have typically been a different race; they'd be people who might speak a little differently or wear slightly different clothes.

I think it's possible for us to take the psychology we've evolved for cooperation within groups and apply it more widely. But that's always under strain. The good news is that the sizes of our "us-es" have grown bigger and bigger. Today, when I give talks about my current work, my first slide is a set of concentric circles going back to Peter's 1981 book The Expanding Circle. As Peter and others have documented, our moral circles have become wider. But the wider they go, the more those relationships can be strained and require greater degrees of cooperation and emotional integration.

You asked whether reason can triumph. I think it's partly about reason, but also about whether we can feel these things in our bones, whether we can identify with someone simply because they are part of our nation, our religion, or ideally, simply because they are another sentient being. I think it's a kind of emotional and rational expansion. We've done a lot of it, but these are challenging times for those of us who would like to see our moral circles expand rather than constrict.

A Moment of Self-Critique and Philosophical Evolution

KASIA DELAZARI RADEK: I'd love to talk about motivation and how to move people towards better behaviour, but I still want to ask about your early years. I've read that your PhD title was The Terrible, Horrible, No Good, Very Bad Truth About Morality and What to Do About It. What was the terrible, horrible, no good, very bad truth?

JOSH GREENE: That's interesting. My doctoral thesis was more meta-ethical. It was about whether there are moral truths, moral facts, or whether it's all subjective. I haven't changed my mind about what the world is like, but I've changed my mind about what is worth pushing on. In the thesis, I argued against moral realism, against the idea that there's a fact of the matter about what's right or wrong, and argued that we would be better off abandoning the usual moral realist language.

The idea was that if we were more transparently subjective about our values, it would be easier to get along. Like in personal disputes, where you're told to use "I" statements instead of saying "you're wrong," you say, "this is how I feel." It was a philosophical version of that. Over time, my thinking shifted. I'm still not a full-blown moral realist, but I don't make a big deal out of it anymore because I don't think that's what really matters.

What matters is whether people's values are open and inclusive. I'm not convinced that getting people to step back from belief in moral truth is a net gain, even if I still agree with the arguments. So, the terrible, horrible truth was that there's no fact of the matter about right and wrong. But I'm no longer focused on highlighting that and maybe it's even wrong. Maybe my arguments were mistaken.

Moral Tribes and the Need for Meta-Morality

PETER SINGER: Before we get to your recent work, let’s talk a bit about Moral Tribes and the view of morality you developed there.

JOSH GREENE: Sure. It brings together a few things. Psychologically, we have what Daniel Kahneman called "Thinking Fast and Slow." I don’t take that too literally in terms of speed, but it's about intuitive versus reflective thinking. Our gut says "don't push that guy off the footbridge", that feels wrong. But our slower, more reflective thinking is where we can apply rules or consider consequences.

Another distinction is between the morality of everyday life, the rules that make life within a group work: don't lie, don't steal, don't kill, what I call the "tragedy of common-sense morality." We’re good at that. But when groups clash, on abortion, immigration, or land disputes like Israel/Palestine, each tribe has its own intuitions, and we can't rely on them to resolve intergroup conflict. That’s when we need a kind of "meta-morality."

If morality is what lets individuals live together, meta-morality is what lets groups live together despite their different worldviews. And I argue that a version of utilitarianism, or what I prefer to call "deep pragmatism", is the best candidate. It capitalises on our shared capacity for happiness and suffering. It’s the only moral philosophy that seriously takes on the challenge of making trade-offs between competing values.

I prefer "deep pragmatism" to "utilitarianism" because people hear "utilitarianism" and think of someone walking around with a spreadsheet. But even John Stuart Mill knew that was a bad way to live. The goal isn’t to calculate everything. It’s to detach from gut reactions and ask what sorts of policies and practices will produce the happiest world.

From Theory to Practice: Giving Multiplier

PETER SINGER: Would you take us now into what you have been doing more recently and essentially how you're trying to change things?

JOSH GREENE: Sure. The two main social impact projects I've been working on for the last few years are Giving Multiplier and Tango. I'll start with Giving Multiplier. And Peter, again, thank you for being such a great supporter of this project.

This was started with Lucius Caviola when he was a postdoc in my lab, and he is currently at Oxford. We were interested in figuring out how to get people to support the most impactful charities out there. As you and many listeners will know, it's possible to do an enormous amount of good with relatively small amounts of money. For example, distributing insecticidal malaria nets at a cost of around $3,000–$5,000 can save someone's life. For under a dollar, you can provide deworming treatments to children, helping them go to school and thrive.

Most people don't do this. They tend to support charities they feel emotionally connected to, which may not be as cost-effective. Originally, I thought we could convince people using philosophical arguments. You were quite successful with the famous "drowning child" analogy. But when we tested those arguments, only a small number of people were moved.

So we asked, what else might work? Instead of saying "don't support your favourite charity, support this more effective one," we said: "do both." We gave people an all-or-nothing choice: your favourite charity or one we recommended. Unsurprisingly, most chose their own. But when we added a third option, split the donation 50/50, more than half of people took it. That led to more money going to the highly effective charities.

Then we added matching funds. If you split your donation, we add extra money to both parts. The question was, where would the match money come from? We asked donors to support a matching fund for future split donations, and enough people said yes. That created a virtuous cycle.

We launched Giving Multiplier in 2020. So far, we've raised over $4 million, with around $2.5 million going to highly effective charities. Most of that money wouldn't have gone to those charities otherwise. The psychological insight here is that people want to act with their hearts, they want to support personal causes, but they also want to do good with their heads. Giving Multiplier resolves that tension by encouraging both.

Tango: A Playful Solution to Political Polarisation

The second project I've been focused on is Tango, which tries to address political polarisation through a cooperative quiz game. The idea builds on the same insights I wrote about in Moral Tribes: we need to bring people together across moral divides and give them experiences of cooperation and mutual benefit.

Players from opposing sides, say Republicans and Democrats, are paired up and must work together to answer questions. The twist is that each group tends to have different types of knowledge. For example, one side might know more about pop culture associated with rural America, while the other might know more about urban trends. Later questions address political issues, where each side has blind spots. The game is designed so that success depends on real collaboration.

In our research, we found that playing Tango increased warmth toward the political outgroup by about 9 or 10 points on a 100-point scale. That’s the equivalent of rolling back 15 years of polarisation. The effects lasted too: four months later, people were still more likely to treat members of the other party more respectfully and share resources more equally.

It’s not just a game. It’s an intervention that works. We’re now working to bring it into colleges, companies, and communities at scale.

On Living Well

PETER SINGER: You've said things that make life good for you and others. So, how is your evaluation of your life? Have you been living well? On what basis would you assess that or reach such a decision?

JOSH GREENE: I've been extraordinarily lucky. I was born into a supportive, loving family that gave me every opportunity. I went to a high school where I learned a lot and managed to get into and attend good schools, where people like Peter could mentor me. And I feel, with some mistakes and ups and downs, that I've been able to put the resources I was given to good use.

Could I have used them even more effectively? I'm sure. Could I have done worse? I could have done worse. But overall, I feel like I’ve been in very fortunate circumstances and have had the great privilege of being able to work on the things I think are most interesting and most important, and to make some progress, while doing it with wonderful people, and at the same time having a family I love.

I'm just in the upper percentile, whatever it is, regarding human good fortune. And I hope that I can spread some of that good fortune around.