The Virtuous Cycle: Pay It Forward

From the Vision archive: Neuroeconomist Paul Zak discusses the so-called moral molecule, the Golden Rule, and the benefit of “big-M morality.” (Republished in Spring 2022 from our Spring 2013 issue.)

We live in a world of transactions and relationships. It’s an economy that reaches well beyond the monetary. “I think any decision—any decision involving tradeoffs, which is almost every decision—would be an economic decision,” says Paul Zak, professor of economics, management, and psychology at Claremont Graduate University. “So every biological system is economic.”

Zak works on the cutting edge of the emerging cross-disciplinary science of neuroeconomics, the study of “brain activity while people make decisions,” he says. Because our lives are embedded in an economy of interactions, it is clear that understanding the neuroscience of decision-making has great value.

At the core of decisions is the question of trust: Why do we trust? Early answers were vague at best. In 1936 economist John Maynard Keynes suggested that “animal spirits” mysteriously inspired “spontaneous optimism,” leading to “a spontaneous urge to action rather than inaction.” This action underpinned a strong economy, he believed, because optimism created trust that conditions would improve into the future. Though Keynes was interested particularly in consumer confidence, issues of trust spill across all human relationships.

Since 2001 Zak and his colleagues have focused on the role of the molecule oxytocin and human behavior. He has dubbed this chemical “the Moral Molecule” because he has found that its release is associated with trusting behavior. “All you have to do to trigger this Moral Molecule is give someone a sign of trust,” Zak writes. “When one person extends himself to another in a trusting way, the person being trusted experiences a surge of oxytocin that makes her less likely to hold back, and less likely to cheat. Which is another way of saying that the feeling of being trusted makes a person more . . . trustworthy.”

His research utilizes a computer-based money exchange he calls the Trust Game. “We often use money because it is a great way to get a sense of what people value,” he says. “You may tell me you care about homeless people, but show me the money.”

To begin the game, participants are each given $10, and the money they have at the end of the game is theirs to keep. Anonymously, another player gives you some of his or her cash. This gift triples in value on your ledger. How much will you be given? How much, if any, will you give in return? In their 2005 paper in Nature, Zak and his colleagues noted the conflict: “The investor is . . . caught in a dilemma: if he trusts and the trustee shares, the investor increases his payoff, but he is also subject to the risk that the trustee will abuse this trust.”

The experimental aspect of this study involves actually giving some players a dose of oxytocin and others a placebo. The researchers concluded that oxytocin was related to “a substantial increase in trust among humans, thereby greatly increasing the benefits from social interactions. We also show that the effect of oxytocin on trust is not due to a general increase in the readiness to bear risks. On the contrary, oxytocin specifically affects an individual’s willingness to accept social risks arising through interpersonal interactions.”

Critics may complain that the conclusions concerning oxytocin are overblown, and Zak certainly recognizes the limitations of chemical and behavioral associations. “Nothing in the brain is 1:1; there are always contingencies,” he agrees. “That’s why we do years of research and, in my case, write a book so the contingencies are made clear.” His book, The Moral Molecule: The Source of Love and Prosperity, was published in 2012.

Vision contributor Dan Cloer spoke to Zak about his work and its implications.


DC Thirty years ago in their book Promethean Fire, E.O. Wilson and Charles Lumsden postulated that moral behavior was in a sense up for grabs—that human behavior is the result of what they called “gene-culture coevolution.” Thus “moral judgment is a physiological product of the brain” and “ethical premises are not immutable or transcendent. We like to think they were handed to us on stone tablets, but they can be changed at will.” Do you agree?

PZ I am looking for this underlying biological basis for morality, but I disagree with the idea that we just make it up as we go.

DC How would you define moral?

PZ As a scientist I don’t come to this question with any philosophical or theological agenda. I mean morality with a small m. My question is, why do people behave in ways that benefit others? Why are we altruistic, trustworthy, honest, generous? These are virtues or moral behaviors that people express all the time, but why would you actually do that, particularly when no one’s looking, when no one will care, and when there are real resources on the line? There’s cash on the table and you can share it or you can keep it. What motivates the decision? How do we manage our self-interests and our interests for others?

DC One metric you describe in the book is to ask, “Would you be comfortable telling your mother you were doing this?” Is that your measure of what is moral?

PZ That’s right. Mom, your spouse, or anyone for that matter; would you be happy if everyone knew that you did this? Morality is socially enforced. If we’re doing something wrong (and we’ve all done this—we’re not nice to someone, we take something from somebody, and later the realization sets in: “Oh, I did a bad thing”), we know it’s bad because as social creatures we need to be connected to our social group. These immoral behaviors (again, small m) say it’s all about me and not you. So what happens if you’re more important than everybody? People start to avoid you, and that’s not adaptive for social creatures like human beings.

DC Social biologists often frame human interaction in terms of kin selection or selfish genes, but you have investigated the neural chemistry of the give-take or share-trust relationship between people. How does trusting others and being trusted in return motivate human relationships?

PZ It’s what the brain is designed to do in most people: it makes us feel good to do good. This brain circuit, which I call the HOME (Human Oxytocin-Mediated Empathy) circuit, provides feedback loops; it gives you this little reward boost when you do something nice for somebody else.

DC How does it operate? How does it stimulate good works?

PZ Oxytocin is a neurotransmitter originally understood to motivate the key reproductive aspects of social bonding and the relationships between parents and their offspring. In human beings, we have a larger mass of oxytocin receptors in the front of the brain, which modulate reward chemicals. Oxytocin also helps reduce anxiety. So relative to almost all other mammals—and only mammals have oxytocin—we have this much bigger mass of receptors that generate in us an overactive connection system.

The product of moral behavior is enhanced survival, because now you are part of a more connected community.”

Paul Zak

When we behave in these moral ways, the brain says: “Oh, that’s nice, keep doing that. Yeah, that was good, that’s valuable.” With the added stress-reduction effect, the product of moral behavior is enhanced survival, because now you are part of a more connected community, and continuing in this behavior helps you fit in with that. We have become hyperaware of these connections in caring for others.

At a conference I heard a presenter suggest that love is the most unusual and misunderstood thing that humans do. But to me it’s the most natural thing. Our brains are designed to love, to connect. And by “love,” I mean philia, caring for others in the Greek sense. It may not be romantic love; it may not be love for children, or transcendent love, but in general, we are connectors. We are group creatures, and the way to connect is to engage in behaviors that we call moral or virtuous. We reach out to others. We care for others. We help others. That can be abused, of course, but for the most part, it’s those behaviors that say, “Look, I’m a good guy, or a good woman. I’m a person you want to be around, a cooperator, a straight shooter. I’m an honest person.” The people from whom we don’t get that sense, we tend to avoid.

DC How universal or variable is this HOME system?

PZ Among the thousands of people I’ve tested, 95 percent have an intact HOME circuit that allows them to get the sense of what’s appropriate behavior. For the other 5 percent, life is dysfunctional for a variety reasons. Of that group, 1–2 percent are psychopaths, individuals who are in permanent survival mode. These people love coming in for our experiments because they can take all the money on the table. We find in their blood a clear dysfunction: an oxytocin deficit disorder. They don’t have the sense of “Oh, I feel bad because I took advantage of this person. I really shouldn’t have done that.” They don’t care about the consequences. They care about now. It’s very difficult for them to learn that their behaviors may be short-term adaptive but long-term maladaptive. This small population doesn’t have the normal cost-benefit calculator that most have. Unfortunately, they are justice-system “frequent fliers”; by some estimates they make up between 25 and 40 percent of the U.S. prison population.

The other couple percent where we see this sort of immoral, nonsocial behavior are people who have high levels of stress. You know that when you’re really stressed out, you’re not your best self. Indeed, high stress inhibits the release of oxytocin, and we have the sense that we’re in survival mode. When highly stressed people are in this temporary mode (as opposed to psychopaths who are in permanent survival mode), for that next hour they aren’t really thinking about other people and consequences. But later they ask for forgiveness: “Man, I was having a bad day yesterday.” Through a functioning HOME system, they understand that that’s not the way to get along with people. We don’t want to be called out for inappropriate behaviors. We want to behave in a moral way to stay embedded in the community.

DC There is also the downside that while oxytocin generates group or community bonding, these groups may coalesce around in-group bias and become aggressive in creating in-group–out-group conflict.

PZ Sure. Just because we release oxytocin doesn’t always mean we are going to engage in loving behaviors. For instance, we did a study of rugby players before a match, and the majority released oxytocin; also, on average, their testosterone levels doubled. So they’re bonding as a unit, but they’re bonding to perpetrate out-group aggression. The combination of testosterone and oxytocin can make aggression feel rewarding. This can be true of gangs, of soldiers, and of other subgroups that humans can be involved in.

DC Is this where the big-M rules of morality are necessary? That the HOME circuit is a real system within us and may create a kind of organic social morality seems convincing, but is that enough? To “love your neighbor as yourself” requires a higher standard than just how I happen to feel.

PZ It’s very important to have absolutes, and I think big-M morality gives us absolutes. Those are vitally important, because all the brain systems that modulate on morality are fallible. Our moral intuition is fallible. When we’re stressed out, scared or angry, we can be pushed too hard. So it’s very nice to have God, society and laws that say, “This is never acceptable behavior.” While these may be a theologically or philosophically imposed set of moral precepts—a Kantian view of the Categorical Imperative, the 613 laws of the Torah, the Ten Commandments—many of these moral systems survive today because I believe they do resonate with small-m morality.

One of the groundbreaking ideas from the New Testament is essentially to love everybody. That’s really hard to do. “The new commandment I give you is just to love.” I think these simple rules resonate with this underlying biology of connection using oxytocin, the molecule that motivated parents to care for offspring. We call that love, but again, in humans—because we have this hyperactive oxytocin system—our love extends more broadly than just to our family. It extends to complete strangers. After 10 years of investigation on the role of oxytocin in people all around the globe, we find that almost everybody has this ability to connect in almost all circumstances. So to me love is the most natural thing. I want to encourage people to use the L-word.

But when things get out of control, when I need to have an anchor, it’s important to have those big-M rules. For secular people, that might just be the laws that we decide on as a society; for religious people it would be the laws handed down from a religious tradition. Those are important points that ground us in the history of human life, and perhaps divine life—rules that give us a path of behaving in ways that are fulfilling in the long-term.

We fundamentally need to be loved and need to love other people, and we do that by service to others.”

Paul Zak

We fundamentally need to be loved and need to love other people, and we do that by service to others. Many of the big-M commandments are about service. Those resonate with us today because they are congruent with our human nature. By embracing that, we can build happier, more-connected lives, and those are moral lives. It is these moral precepts, which put others ahead of ourselves, that pay huge dividends.

It’s very hard to study neuroscience and not be tolerant of the vast variety of ways human brains work in the same setting. We tend to be moralistic (“He’s wrong!”), and certainly there are things that are just wrong to do, but often it is just poor decision-making, lack of insight. I have spent much of my life trying to figure out the biological basis for morality, but I didn’t understand the connection to empathy until I started doing this work. That was a shocking discovery.

DC Can this chemical system be changed by behavior?

PZ We have some evidence in humans that this system adapts pretty rapidly, and so things like moral education, training, religious rituals in which we are reminded about the value of sacrifice, the value of loving others, are important. There is evidence in animals that the more you release oxytocin, the easier it is to release it. So it seems you can reduce the threshold for release.

In almost all experiments we run, I am the first subject. I have worked on myself for a number of years to develop ways to release oxytocin. One way is hugging people. Doing that has trained my own brain to release oxytocin. In the last five years I have become much better at connecting to people, about reading their emotions, being empathic and even being loving toward people and not feeling weird about it. In just focusing on connection I feel like I am much happier; I have a much richer social life; the friends I have are much better friends because of investing in those relationships, and of course, children and family benefit greatly.

So yes, the system is potentially trainable. The call for action in the book is to expand that sort of empathy. Of course, we must view others appropriately if they actually are a threat, but for most people—people who are neurologically healthy—if you treat them well they are going to treat you well. That’s the Golden Rule.

The Golden Rule exists in every culture on the planet. And I think it exists because that’s exactly what oxytocin does. I treat you nicely, your brain releases oxytocin, and you are motivated to reciprocate. Every experiment we’ve done shows this; and the reciprocation, because the system is so blunt, can be very broad. It’s not that you want to reciprocate toward me; you may reciprocate toward another individual.

Essentially it says you need to start to pay it forward. Someone has got to start this virtuous cycle in which I am good to you, your brain releases oxytocin, and you are good to somebody else; their brains release oxytocin, and they are good to somebody else. If an aggressor comes into the loop, don’t worry; your brain will turn on those fight-or-flight chemicals rapidly. We do not need to live in a defensive mode.

I think it is possible to use this work to build both happier lives and happier societies. Part of it is just embracing our need for connection as human beings, and recognizing that connection has a cost and that we need to invest. We call the cost “virtuous or moral behaviors.” Like the New Testament suggests, you just need to give freely and good will return.

DC Many people look to Adam Smith and Wealth of Nations as a guide to economic and community success. But you suggest that his work has been misinterpreted. You also write that your economics education was “empathy-free.” Would you say now that Smith’s “invisible hand” was not actually profit but empathy?

PZ That’s a great question. The reason you write a book is to find context, to find what this tells us, how we use it. The strongest context I found was with Adam Smith. Many people think his 1776 book, The Wealth of Nations, the founding document of economics, is the most important thing he ever wrote. In fact, Smith was a moral philosopher and in 1759 wrote his greatest book, The Theory of Moral Sentiments.

It was this book that took this odd, small-town Scottish professor—who would sometimes forget to put his clothes on and would walk around in his pajamas and lived with his mother until she died—from Edinburgh to the courts of France and the leaders of the American Revolution. Why? Because Smith claimed to have found in The Theory of Moral Sentiments the first fully developed theory of human morality dependent on what he called mutual sympathy. We would call it empathy today.

And he said the reason that we are moral creatures is because we are social creatures and that we can’t help but reflect the emotions of others. And by doing that we get a sense of what’s appropriate in terms of behavior. It really changed people’s thinking substantially and then was forgotten.

Then he wrote The Wealth of Nations, about the importance of self-interest to drive innovation and prosperity, but we forget that this second book was founded on the first. There he said that this is all about serving others, about connections to others, and about understanding what others need. That is what makes us moral and makes markets operate. Our work has shown that trust is one of the key predictors of which countries will be rich or poor. High-trust countries have more economic transactions, create more wealth, and help alleviate poverty. Smith would look at us and wonder, “It took 200 years for you guys to figure that out?”

There is anthropological evidence in small-scale societies and survey evidence in developed countries showing that increasing economic transactions actually increases morality, because it gives us a chance to exercise morality by serving others. Even though we are getting paid for that, it’s still about service to others. I think we wouldn’t have modern economic systems where no one is in charge, because everybody is in charge without something in our head (and the mechanism seems to be oxytocin) that guides trust and choice based on understanding what others need and taking the opportunity to fill that need.