What do a disease-fighting epidemiologist (retired) and an up-and-coming social psychologist have in common? They’re both fascinated by the unseen social problems hidden behind the word “inequality.” Beyond the lack of access to money and power — what does inequality do to us as human beings?

Epidemiologist Richard Wilkinson (TED Talk: How economic inequality harms societies) spent his career studying chronic health problems — with the growing realization that most health issues are caused, or worsened, by poverty and inequality. This awareness led him to co-found the Equality Trust and co-write the book The Spirit Level: Why Equality Is Better for Everyone). Meanwhile, social psychologist Paul Piff (TED Talk: Does money make you mean?) studies the psychological effects of wealth — and what happens when you, say, rig a Monopoly game.

In this freewheeling conversation, Wilkinson and Piff find their common ground — and go from there. A lightly edited version of their conversation follows:

Paul Piff: Richard, maybe we could begin with a description of where you started, and some of your basic findings and how that converges with mine.

Richard Wilkinson: Well, I got into studying inequality from, really, studying health inequality, the huge social-class differences in death rates between rich and poor, between well-educated and badly educated, between people in rich and poor areas, and so on. In most of our countries, people in richer areas live anywhere from 5 to 12 or even 14 years longer than people in poor areas, and that’s always seemed to me like the biggest human-rights abuse you could imagine, worse in a way than locking people up without trial. And people around the world were doing research on the causes of these health differences, and I focused particularly on income, trying to see if health was responsive to changes in income, and from there thinking that the death rates of the poor are more responsive to changes in income than the death rates of the rich were. I thought maybe countries with greater equality — with the rich less rich and the poor better off — would have better overall health. And I found that was much truer than I would have imagined. The relationships I looked at first, I’m talking about the mid-1980s, were much closer than I imagined. With each step up the inequality ladder, bigger income differences between rich and poor, the worse a country did in terms of life expectancy. Very striking relationships.

PP: Yours is some of the work that best shows how inequality shapes people’s individual lives. It sheds light on how inequality shapes the very fundamental outcome of someone’s life, like their health, the physical symptoms of a person’s body. The broad agenda of my research, and it really dovetails with yours, is how inequality and differences in people’s levels of wealth shape the mind, shape the way people see the world and behave towards one another. I’m a social psychologist, and I’m really interested in how status, inequality, stratification, shape the basic things people do, like their tendencies to feel compassion, their tendencies to cooperate with others. These are fundamental questions in psychology. What is it that drives people to band together versus prioritize themselves? One of the broader lessons we’ve been learning over the last 10 years of research is that, in lots of really interesting ways, a person’s levels of wealth, and their status relative to others in their society, shape their tendencies to prioritize themselves, feel entitled, to cooperate versus behave in self-interested ways, across a variety of different domains of social life.

RW: Yes, it sounds like you got into the psycho-social effects of status and inequality from the beginning. But in health, we started off imagining that differences in rates of disease had entirely material causes. And then gradually it looked as if there were psycho-social factors mediated by chronic stress, which acted as general vulnerability factors in health — in a way looking like the effects of more rapid aging, making you more vulnerable to a whole range of diseases. But the most important stressers seem to be things to do with social relationships. For instance, friendship seems highly protective of health, and things to do with low social status are very damaging. The other part of that picture is that a difficult early childhood, stress in early life, seems to cast a long shadow forward. The picture of the importance of these psycho-social things is now really strong, so that in the rich, developed countries, psycho-social factors look like among the most important influencers in population health.

PP: I was curious, when you mentioned psycho-social factors, I just wanted to know a little bit more about the kinds of psycho-social factors you were referring to.

RW: Well, the biology of chronic stress, I suppose, is fairly similar across a wide range of mammals. And in human beings, we had always regarded classification by social class as simply a proxy for the real determinants of health that we saw, that we imagined were material factors — like diet and what you’re working with and what you’re exposed to at work and maybe housing, air pollution, things like that. But gradually, it started looking more and more like social status itself was a really important determinant of health, and that was really confirmed when we became aware of people doing work on non-human primates, macaques and baboons, looking at some of the psycho-social, the stress effects of social status in those animals, and seeing remarkable parallels between what came out of experiments in animals. You could manipulate social status by moving animals between groups, and you could give them the same material conditions and feed them the same diets, and you saw that the social status changes under those conditions had remarkably similar effects to what we were observing associated with social status in human beings. But I suppose I regard social status, ranking systems, as almost the opposite of issues to do with friendship. I think the fundamental issue is whether we fight each other for access to basic necessities, or whether we recognize each other’s need and share access, and one is about status and power and the other is about friendship and reciprocity. Inequality pushes us away from the reciprocity towards competitive striving for personal, individual advantage, not recognizing the other’s needs.

The fundamental issue is whether we fight each other for access to basic necessities, or whether we recognize each other’s need and share access.

PP: Inequality gets reflected in a fraying, if you will, of the social bonds, of social cohesion. It leads to, in many ways, a dissolution of the trust that emergent groups and strong, cooperative groups rely on. One of the things that’s striking to me, and you mentioned work in health and in health psychology, is that for many years, a lot of the research on health and inequality gave rise to this understanding that it’s really the people who feel subjectively lower on the social ladder or who are objectively poorer, who experience all the negative outcomes, whether it’s higher rates of obesity, or increased cardiovascular disease, or higher rates of depression.

Inequality is genuinely bad for those on the bottom, and there are a lot of really intuitive reasons to think about why that might be: They have less control over their own lives. They have less access to resources. They get less respect in the scene, in their social groups. But one of the emerging insights out of our work — and I think your work, Richard, also points to this — is that inequality isn’t just bad for a certain subsection of the population. It’s not just bad for the people on the bottom. It’s actually bad for the group as a whole. In our work, we’re finding that there are these really interesting social costs associated with wealth, in a sense. Wealth shapes behavior in some potentially counterintuitive but certainly pernicious ways and causes people to abandon certain kinds of ethics, to prioritize their own interests over the interests of other people, to behave in ways that are potentially less trustworthy, less honorable. They become more competitive, less compassionate, less moral in certain ways. And your work also suggests that there are costs associated with inequality that resound across all strata of society and not just among those on the bottom, and I wondered if you could say a little bit more about why that would be. Why is it that inequality is costly potentially for everyone and not just those on the receiving end?

RW: We find the biggest effects of inequality are lower down in the social ladder, but it looks to us as if the vast majority of the population is adversely affected by increases in inequality. Simply, people on the bottom of the social ladder are affected more than people further up. And I think that’s because inequality changes the whole social milieu, if you like. It leads to more status competition, more status insecurity. Status becomes more important, you know. Some people are incredibly important, while some of the people at the bottom seem almost worthless — but we all become more worried about where we are. Think of this as an evolved sensitivity to social ranking systems — if we’re in a social environment where rank is important, we are very sensitive to that. We know how to play games to do with status and how to be snobbish and so on, put people down, build ourselves up. But we also know how to develop friendships on the egalitarian basis of friendship. Those are two different ways in which people can come together, and I think the nature of the material differences between us tells us what kind of game we have to play in our society, whether it’s about reciprocity, recognition of each other’s needs, or whether it’s everyone for themselves.

And ranking systems, I think your work shows that very clearly, ranking systems are about self-interest, and the sense of entitlement. Further up, it looks to me very much like the dominant baboon. He’s able to see off the subordinates and can basically do what he likes, rather the way these people with big bonuses have been doing with the runaway top incomes. I’ve been interested in some papers showing that bullying in schools is much more common in unequal societies, because I think that, in a way, hierarchies, certainly in animals, are about bullying relationships. Ranking systems are rankings based on power, and the dominants can see off the subordinates, and whether that’s a nice place to sit in the shade or whether that’s eating first, the dominants have it. Although we don’t have good measures of bullying amongst adults, internationally comparable measures, we do for bullying amongst children, and I think to see those bullying relationships coming out even amongst children among more unequal societies is quite remarkable.

PP: It would suggest that the markers, the effects, the consequences of inequality on the vigilance to status, the anxiety about status, the vying for status, that you see emerge in groups, in societies with increasing levels of inequality, is found not only among the adults, who have already formed an understanding of where they stand in relation to others, but it’s also reflected in the behavior of children, suggesting that the signs of inequality, the manifestations of status anxiety and concern about where one stands in relation to others, emerges very, very young, and is something that people begin to carry around with them or that shapes a person’s life very, very early on.

RW: I’m quite sure that’s true. The very life influence is, I think, powerful and probably includes epigenetic effects, epigenetic responses, ways in which the early environment switches genes on and off, changes gene expression. So, brought up in one environment, you will develop differently than if you were brought up in another environment, and I think family relationships, whether you have a depressed parent or you have a lot of domestic conflict or parents too exhausted to have time for you, all of those things affect your development and lead to being less fully socially developed, compared to if you’re brought up with parents who have a lot of time for you, get used to a lot of eye contact, interaction, handling, physical contact, all that kind of sharing develops you in a much more social way. So I think these things feed into, again, whether you are being prepared to live in a society where we have to fight for what we can get, learn not to trust others because we’re all rivals, or whether we are being prepared for a world in which we will depend on reciprocity and cooperation, where empathy is important. And those are very different developmental trajectories, but I would imagine that you as a psychologist would know more about those kinds of developmental patterns.

PP: Yeah, and it’s interesting that you bring that up. In our work and the work of sociologists and ethnographers studying different kinds of families and parenting patterns as a function of status and wealth, it yields this understanding that the values that children grow up with are often a function of their family’s socioeconomic status. So for instance, the kinds of things that parents value and stress as being of value to their kids often vary as a function of income, often vary as a function of wealth. For instance, whether the family stresses personal achievement, the expression of your individual talents and desires, standing out from the pack — seems to be more a value of individuals in families of upper socioeconomic standing, relative to the values of families that emerge out of lower socioeconomic groups, which really stress the community, relating to others, valuing the well-being of others, and not standing out from the pack but rather fitting in. And it’s interesting to think about how those values might play into the kinds of things you prioritize in your daily life, what kind of jobs you would go for, and also the emergence of exacerbating levels of inequality over time because of what one socio-economic group may or may not value relative to another socio-economic group.

RW: Yes, I agree those patterns are important. I should have said, behavioral outcomes like violence or teenage births or drug abuse. There’s a paper by Sheri Johnson, who you may know, writing about what she calls the dominance behavioral system, showing that there are psychological responses to status differentiation. If you’re in a status hierarchy, then there will be amongst some people a struggle to avoid subordination, or an acceptance of subordination, or a struggle for dominance, and those all contributing to a range of, I suppose, mental illnesses and personality disorders, and I think she mentions things in particular like depression and schizophrenia and antisocial personality issues, all perhaps exacerbated by issues to do with dominance and subordination in our societies.

PP: Yeah, and I think that work is really compelling. In your own book The Spirit Level you talk about not only these kinds of outcomes, for instance incarceration rates, but also various kinds of psycho-social outcomes or consequences of inequality and rising levels of inequality. For instance, we talked about social trust, and did you find, for instance, growing rates of depression in societies with greater levels of inequality?

RW: Other people have. It’s not our work, but there are several papers showing that tendency, for depression to be more common in more unequal societies. There’s another paper showing the same of schizophrenia, and I think Sheri has just completed a paper on psychotic symptoms, which seem more common in more unequal societies. So there are a number of ways in which issues to do with being better or worse than other people, superior or inferior, intrude on social relationships and affect us very deeply. It’s extraordinarily destructive of good social relationships that are so essential to human wellbeing. We all know what we most enjoy is sitting around chatting and joking with friends we are at ease with. It’s damaging to that kind of fellowship.

PP: Yeah. I absolutely agree with that. In our own work, when we ask people to reflect on those things in their lives that they found the most meaningful, people rarely point to individual achievements and the things that they did to outperform and outcompete others. Now, those things are important to well-being. It’s important to think you have done things that are worthy and valued by others. But far more often, people refer to those episodes where they were embedded with a community, those experiences where they really connected with others, connected with loved ones, felt valued, trusting of others, felt like others were respecting of them, like they were actually reaching some deep connection with their social relationships. And I think that’s a really important insight into what it is, both in terms of psychological values but even what the human nervous system, people’s physiological systems, health systems are wired to value and prioritize. It’s really social relations, cooperation, interdependence in many ways. And so social inequality and a constant vigilance towards status and anxiety about where you stand in relationship to others, which you would argue and I would agree is exacerbated in groups with lots of inequality — well then, those are the very things that undermine the social relationships, the trust, the embeddedness, those things that we as individuals care about deeply and that deeply and significantly contribute to our well-being and ultimately to our satisfaction with our lives.

when we ask people to reflect on things in their lives that they found the most meaningful, people rarely point to individual achievements and the things they did to outperform others.

RW: When societies become more fearful, less trusting, less empathetic, you see this more punitive approach to crime. I mean, that’s why imprisonment is more common in more unequal societies, much more common. In unequal societies, perhaps 10 times as high a proportion of the population is imprisoned as in more equal societies. And that is not mainly more crime, it’s mainly about longer sentences. And that is a sign of something going badly wrong with the quality of social relations.

PP: Right. Right. Yeah. As I think about it, this is just a caricature of the work in certain ways, or a generalization, but it’s such an important point, and it makes sense that with inequality emerges an increased awareness and increased incidence of those things that separate people. So with increased inequality come increased markers of status. Your differences, the differences between people become ever salient, and with those factors, whether it’s differences in material well-being, differences in the kinds of cars people drive or the homes they live in, the jobs they have, if those things become increasingly disparate in society, with growing inequality in society, then so too is the decline of trust, those things that you see as making you similar to other people or that are essential to forging relationships and forging independence, people’s relationships become increasingly frayed. Trust will go down. Those perceived similarities between yourself and others will go down, and so too then would the other effects sort of ricochet and resound, like incarceration rates, and this is obviously patterns that emerge over time, over long periods of time, this isn’t something that happens from A to B to C to D in seconds. It’s really an unfolding cascade of effects, but I think it’s a really compelling point to think about how all of this emerges out of the fraying of the social fabric that is a consequence of rising rates of social inequality.

Here’s one of the questions that comes to my mind. I think you, Richard, have encountered criticism of your work or of related work, and I know a lot of our research and other research on the psycho-social effects of inequality has been met with criticism, and it brings to mind an interesting question: Why is it that some people have a resistance to discussing inequality? It’s there, people are aware of it, but why is economic inequality such a controversial, intractable topic in conversation?

RW: I often think it’s because people misunderstand some important causal connections. The common view I suppose is, if you’re bright, you move up the social hierarchy, and if you’re not, you move down, and people feel their position is a reflection of their ability, and we judge each other’s ability by our position in the social hierarchy, and that’s why it’s so hurtful in a way. We take external wealth as an indication of social worth. But the causality, I think, goes mainly in the opposite direction, that differences in ability are much more of a result of the position in the social hierarchy in which you are born and brought up, with fewer opportunities or perhaps less education, a whole range of things like that. I don’t know if you know the stereotype threat experiments, which show that being made to feel inferior in one way or another, how powerfully those affect performance. So rather than your position in the social hierarchy being a reflection of your innate ability, as we learn more about the malleability of the human brain in early life, it becomes clear that the causality is the other way around.

PP: Right. Right. Right.

RW: And I think that’s really crucial.

PP: I think that’s really well put, and in American society, I think talking about inequality, as important as it is, it’s an anxiety-provoking issue, and I’ve been thinking recently about the range of reasons, the myriad reasons why that might be the case, because certainly talking about an important issue is an important step towards being willing to make changes or take efforts toward rectifying whatever that issue might be, including the issue of economic inequality. And it seems to me like the issue of inequality, and certainly the issue of deservingness, comes up once you start talking about social mobility, which itself is sort of a hallmark of the American Dream. American society, in many ways, is built on this explicit idea that if you work hard, because of your individual talents and efforts you can rise in the ranks and attain those things we value so much as individuals. If we begin finding that social mobility isn’t actually randomly distributed across society, that it’s actually concentrated in a particular subgroup, and in particular it’s concentrated among those who are already fairly high up in the hierarchy, well then, that could be a problem, because it suggests that this meritocracy, this society that we want to believe is really premised on individual deservingness where people get what they work for and get what they deserve, well, that’s not the entire story, and that’s a dissonant, threatening thing to accept.

RW: Yes, I remember we published some data suggesting that social mobility is lower in more unequal societies, and we published it when there was very little comparable international data on social mobility, but since then there have been several more demonstrations of that tendency toward lower social mobility in more unequal society using independent data, including one study by Alan Krueger, who is I think chair of Obama’s economic advisory committee, and what inequality does is I suppose strengthen the ability of the wealthy to pass on their advantages to their children, but I also think it strengthens what I also call downward social prejudices. The prejudices, whether it’s class or ethnicity or prejudices against women, prejudice against any weaker group, I think is strengthened by greater inequality, because inequality is about dominance and looking after yourself, often at other people’s expense.

PP: Richard, you mentioned dominance hierarchies among non-human primates or even other mammalian species beyond primate societies or primate groups. So there is reason to think that dominance hierarchies, status, not necessarily social status per se, but dominance and stratification, are a part of life, are in certain ways a fundamental part of how mammals come to be in existing groups. In certain ways, dominant hierarchies can be efficient. They help coordinate action. They help coordinate group life. They help coordinate who does what. And so I don’t know that we could eradicate them even if we wanted to, or that it would even be wise to argue for the eradication of inequality or dominance hierarchies.

RW: The sort of income differences we have in the United States and Britain are twice as big, and if you compare as we do the income going to the top and bottom 20% of the population, the gap between the top and bottom 20% is twice as big in countries like the United States and Britain as it is in some of the Scandinavian countries. And so there’s no doubt where we can have societies with very different levels of inequality. But I think also it’s worth remembering that throughout most of the human existence, prehistoric existence, as hunters and gatherers, you know, we typically lived in very egalitarian societies. I don’t know if you know Christopher Boehm’s recent book Moral Origins, and I think it’s extraordinary. He’s now put together electronically searchable data on I believe 200 hunting-and-gathering societies showing this pattern of remarkable equality. Inequality begins in these terms relatively recently with agriculture, the beginnings of agriculture, in the last few thousand years. And so I think it’s clear human beings have lived in everything from the most egalitarian societies to the most hierarchical, and I don’t think we should regard ourselves as fixed in any way. And indeed, if you think of our closest relatives, non-humans, chimps and bonobos, one, the chimp, is fairly hierarchical, and the bonobo much more egalitarian. The bonobos, I believe the females are smaller than the males, as often happens, but the females eat first, and their social structure is very different. I think it’s important to recognize, as humans, our culture determines how we behave. But our evolved psychology means there are particular aspects of our environment that we are sensitive to, and again and again it seems to me this issue of friendship and reciprocity versus dominance and the pursuit of self-interest.

it’s clear human beings have lived in everything from the most egalitarian societies to the most hierarchical, and I don’t think we should regard ourselves as fixed in any way.

PP: Yeah. And I really like the point that you raised about human nature not being fixed and that people really are in many ways quite malleable and sensitive to changes in the external environment, changes in culture, and that the ways in which behavior emerges and manifests itself are really quite malleable. And in our work, if it’s the case, as we’ve been finding, that wealthy people and less well-off people behave differently, well, it’s also the case, as we’ve been finding, that, for instance, the empathy gap that we often document between those that have and those that don’t, isn’t in any way fixed. It’s not the case at all that wealthy people are characteristically bad and that there’s no way in any way to change their behavior to the positive ends of the spectrum –rather that little behavioral nudges, little reminders of more egalitarian social values, or little bursts of compassion, can have these really interesting and important effects, which would suggest that the effects of inequality, at least on a social, behavioral level aren’t irreversible at all but are really rather quite sensitive to even subtle changes to people’s environments and people’s values.

RW: And in relation to that, what can you say about whether high-status people that you’ve shown behaving badly in a number of ways, whether they’ve been selected with those characteristics, or whether it’s their high status that makes them in some ways more anti-social?

PP: So this is the question, it’s a good question, is it one of causation versus correlation?

RW: Well, it’s easy to imagine people who are out for themselves are dominant.

PP: There’s reason to believe that that’s at least in part what’s going on. I know that there’s other work outside of ours that suggests that people who value individual achievements more are going to be slightly more likely to rise in the ranks of an organization and potentially in groups. But it’s also the case that we’ve been finding a bi-directional thing happening, such that self-interested people over time may be more likely to aggregate resources and become more dominant, although there’s work on Machiavellianism and people who get demoted in groups which suggests that the antisocial people are not those who maintain positions of dominance and leadership but may be more likely to rise over time. But our work would suggest that there is also another arrow flowing from being dominant, being in a position of power, high status, and wealth, that actually causes you to be more entitled or to become more self-focused and self-interested, and in fact, in a lot of our studies, and this is work that’s been shown in other laboratories, is that when you make people, even those who are actually in their real lives not all that high status at all, not that dominant at all, when you bring those people into the lab and make them feel, even temporarily, better off than others, or make them feel more powerful, or make them feel subjectively higher in status or higher in rank, all of a sudden they begin to behave as if they’re actually wealthier or more high status. So this subjective perception of where you stand in relation to others, in particular feeling like you’re better off than others, actually makes you more entitled, more prioritizing of your self-interest, and, in our studies, sometimes more unethical, more likely to even be willing to break the rules.

RW: Does your work suggest that high-stakes people treat everyone badly or just their subordinates badly?

PP: That may be part of what’s going on. We often study the behavior of people towards strangers, so situations are absent cues about who the person is you might be helping, but by default, it might be that wealthier, higher-status individuals just naturally think that they’re going to be interacting with someone who is a subordinate. So it might be in a lot of cases what we might be doing is measuring behavior of high-status individuals toward people that they presume or believe are lower in status. And in fact this is an issue we’re exploring right now, it’s not data that’s out yet, but we’re actually finding that although in general it’s true that higher-status individuals are less socially engaged, less considerate of the needs of others, in general, when it comes to peers or particularly individuals that are even higher status than them, you see a slight reversal in their behavior. Whereas initially they were, say, more self-interested toward a subordinate, when it’s a peer or someone who is in their social group, or someone that they hold in higher esteem than themselves, their values reverse a bit. They become a little bit more cooperative, a little bit more respectful, almost as if they’re becoming a subordinate, taking on some of the characteristics of a slightly poorer person. They become more agreeable, more compassionate, more socially engaged, more socially considerate.