Joshua Greene thinks we suffer from "The Tragedy of Commonsense Morality." Our moral intuition evolved to enable ingroup cooperation. But the world has changed. Modern technological societies exist at tremendous scale. Our daily institutions—work, school, commerce—now require cooperation from outgroups. We're not good at this.
Moral Tribes was written in 2013. It was hugely ambitious. Greene wanted to lay the groundwork for a rational approach to moral discourse. He was in many ways unsuccessful. The book was met with middling reviews. The Guardian was particularly harsh, calling Greene's work "crude reductionism."
[using a] fashionable mix of game theory and sociobiology… Greene tends to displace culturally accreted understandings [with] clever-sounding theoretical notions — including ideas borrowed from the prevailing versions of market economics.
Gosh. That sounds really bad.
The New Republic was more reserved, but ultimately critical.
Greene is wrestling with an old problem, and his psychological approach does not enable him to solve it.
Which is true. Greene has not solved morality. But a careful reading of Moral Tribes predicts why a major newspaper would prefer to slander Greene for using (very hip) techniques like psychology and economic theory instead of deferring to their timeless tribal norms.
The Assumptions
Greene borrows the pastoral metaphor popularized by Garrett Hardin in the seminal essay The Tragedy of the Commons. He conceives of contemporary tribes (e.g., Republican, Democrat) as herders on new pastures. Although each tribe possesses an internally consistent morality, these political systems are incompatible when intermixed. Members of one tribe find the practices of other tribes self-serving and dishonorable.
But an alien anthropologist, witnessing everything from afar, might instead note that the conflict arises in no small part because of cross-tribe similarities. For all herders:
What they perceive as unjust makes them angry and disgusted, and they are motivated to fight, both by self-interest and by a sense of justice. Herders fight not only for themselves but for their families, friends, and fellow tribe members. They fight with honor and would be ashamed to do otherwise. They guard their reputations fiercely, judge others by their deeds, and enjoy exchanging opinions.
These traits aren't accidental. They were designed to solve the critical problem of ingroup cooperation.
Nearly all human relationships involve give-and-take, and all such relationships break down when one or both parties do too much taking and not enough giving. In fact, the tension between individual and collective interest arises not only between us but within us. … Complex cells have been cooperating for about a billion years. Nevertheless, it is not uncommon for some of the cells in an animal's body to start pulling for themselves instead of for the team, a phenomenon known as cancer.
Greene goes big here. As a whole, human emotions—including anger, gratitude, and love—are designed to facilitate cooperation. For example, we know it's not rational for strangers to cooperate in a non-iterated prisoner's dilemma. But what about friends? If two people genuinely like each other, they share emotions. They feel good when their friend feels good. Seeing the other suffer makes them sad. For genuine friends, cooperating is the selfish choice.
Disgust and anger have a similar effect by a different route. Why should two criminals, Art and Bud, not rat on each other once they are caught? Well, what if Art knows Bud to be angry and vindictive? Art might predict Bud is truly unhinged—and that if he is betrayed, Bud will ignore all future incentives in favor of revenge. Anticipating Bud's emotional vendetta, Art may (selfishly) cooperate.
Our being, to its very core, is designed for ingroup cooperation. And this is incompatible with outgroup cooperation.
Cooperative tendencies cannot evolve (biologically) unless they confer a competitive advantage on the cooperators. Imagine, for example, two groups of herders, one cooperative and one not. The cooperative herders limit the sizes of their individual herds, and thus preserve their commons, which allows them to maintain a sustainable food supply. The members of the uncooperative group follow the logic of self-interest, adding more and more animals to their respective herds. Consequently, they erode their commons, leaving themselves with very little food. As a result, the first group, thanks to their cooperative tendencies, can take over… Cooperation evolves not because it's "nice" but because it confers a survival advantage.
No competition means no cooperation. Ingroup and outgroup are ingrained categories. Greene largely takes this as obvious and self-evident, but he does provide a few examples to demonstrate the effect.
He cites research by Geoffrey Cohen that asked participants to rate political policies, both with and without tribal endorsement.
The effect of partisan support completely obliterated all effects of policy content. Liberals liked extreme conservative policies in conservative clothing. Conservatives did the same thing. [Further], most subjects denied that their judgements were affected by the partisan packaging. It's all unconscious.
More surprising might be the relationship this machinery has with race. Robert Kurzban conducted a study where he asked participants to watch a (simulated) conflict between two mixed-race basketball teams.
The participants saw pictures of various players paired with partisan statements such as "You were the ones that started the fight." The researchers then gave their participants a surprise memory test, asking them to pair pictures of people with the things those people said. By looking at the kinds of mistakes people made on the test, the experimenters could see how the participants were categorizing the players. If people in this experiment are highly sensitive to race, then they should rarely misattribute a white person's statement to a black person, or vice versa.
In the absence of salient markers of team membership, people paid a lot of attention to race and not a lot of attention to team membership. However, when the players wore colored T-shirts indicating team membership, everything reversed. Team membership mattered much more.
There's a clean explanation for this hierarchy. Race is unlikely to be a natural evolutionary category. Humans tend to interbreed with those around them. Thus, for most of human history, peoples living in close quarters were visually similar. For race to develop, there first needs to be near-complete separation, and this typically requires a near-insurmountable geographical feature, e.g., a mountain range or a desert. It is only after a great migration—which must be rare; frequent migration would not build "race" in the first place—that humans experience interracial living. And these mixed-race worlds are relatively short-lived. A mixture of love and violence generally leads to relative homogeneity.
That is, our modern world is mixed-race because we happen to live in the time period shortly after the invention of cheap, safe travel. We take race for granted, but for most of human history the typical human may have been unlikely to encounter it. Thus we can make an educated guess: the mechanisms that enable racism are likely exapted from, and subservient to, tribalism.
And here we start getting into the thick of Greene's theory. Intuitive morality makes Us / Them interactions worse. In these cases, it's better for us to try to be amoral. Take, for example, a mock trial conducted by Fieke Harinck. Participants were randomly assigned to the roles of prosecutor or defense lawyer. They were given asymmetric goals, such that finding differing concessions could yield a win-win scenario. But:
The twist was in how the negotiators were told to think about the negotiation. Some pairs were told to think about the negotiation in purely selfish terms, to try to get lighter/stiffer penalties because doing so would advance their careers and help them get promoted. Other pairs of negotiators were told to think about the negotiation in moral terms; here, the defense lawyers were told to pursue lighter penalties because lighter penalties are, in these cases, more just. Likewise, the district attorneys were told to pursue stiffer penalties because stiffer penalties would be more just.
So who did better? The surprising answer is that the selfish careerists did better. Bear in mind that the selfish careerists did not succeed by trampling over the seekers of justice. The selfish careerists were negotiating with each other. What Harinck and colleagues found was that two people told to negotiate selfishly were, on average, better at finding win-win solutions than two people told to seek justice.
Greene calls this the Tragedy of Commonsense Morality. When things start going sideways, our instincts are to turn up our moral circuitry. This facilitates ingroup cooperation but hinders between-group cooperation. The defense lawyer gets emotional about harsh penalties. The prosecutor gets emotional about victims and vengeance. There's a deluge of disgust, sadness, dehumanization, and anger. What's a (colloquially) Autistic neoliberal to do?
Trolleyology
Here's a familiar dilemma:
A man with a backpack is standing on a footbridge above a trolley track. Pushing him and his large backpack onto the track will stop a speeding train from hitting five workmen in a tunnel. Is it moral to do so?
A large majority say no. But consider the following:
A trolley is going to hit five workmen in a tunnel. You can flip a switch so it instead hits a single workman in a separate tunnel.
Here, most of us choose to flip the switch. But Greene, who is a utilitarian, considers these two scenarios morally identical. He calls the response disparity "the perfect scientific problem." And, to his credit, he solved it.
The first puzzle piece came from patients like Phineas Gage. If you haven't already heard, Gage took a tamping iron to the skull, which left a large hole in his brain. His general cognition appeared unaffected; it was his ventromedial prefrontal cortex (VMPFC) that took the brunt of the damage. Damage to this area results in emotional deficits. Individuals often fail to respond to emotional cues in others, and, in extreme cases, they experience little to no emotional qualia when exposed to gore or other human suffering. And, Greene would later show, they treat the two trolley problems above nearly identically. For them, pushing a human onto the track is the same as flipping a switch.
But although most sociopaths push the backpacker (Bartels & Pizarro 2011) not everyone who pushes the backpacker is a sociopath. When a Harvard neuroscientist like Greene pushes the backpacker, it is likely because he has a particularly active dorsolateral prefrontal cortex (DLPFC). This region of the brain is associated with cognitive control. For example, in the Stroop task a volunteer is presented with a mismatched image:
Their task is to either read the word or name the color. When they are mismatched, doing either is cognitively taxing, but the DLPFC makes it possible. Greene, with the help of his collaborator Jonathan Cohen, hypothesized that fMRI data from these regions would be predictive of behavior in trolley problems.
And that's exactly what he found. Scans showed that when we consider the personally visceral problem of pushing someone with a backpack off a footbridge, our VMPFC (or, loosely, our emotions) is most active. In contrast, when we consider the (impersonal) switch problem, our DLPFC (cognitive control) is dominant. And what about the rare individual who takes a consequentialist approach to the visceral case? It's a simple but elegant model: they suppress their instincts and take a rational approach. Their fMRI will show an active DLPFC.
We can formalize this with a graph.
For the pushing problem, those below the dotted line are cognitive-control dominant and choose to act. Those above are emotionally dominant and do not harm the backpacker.
This is Greene's dual-process theory. It's both a specific theory and an overarching metaphor for moral conflicts. He likens it to Kahneman and Tversky's fast/slow thinking. There are real similarities. Research has shown that when put under time pressure, we are less likely to push the backpacker. Additionally, a separate study by Adam Moore showed that stronger cognitive control, as measured by performance on working memory tasks, predicts "utilitarian" actions in a variety of similar scenarios.
There's even better evidence that stronger emotional reactivity prevents one from endorsing a push:
Molly Crockett and colleagues gave people citalopram, an SSRI like Prozac, and had them respond to our standard set of dilemmas. A short-term effect of citalopram is the enhancement of emotional reactivity in the amygdala and the VMPFC, among other regions. As predicted, they found that people under the influence of citalopram (as compared with a placebo) made fewer utilitarian judgements in response to "personal" dilemmas like the [pushing] case.
Quick aside: this is not what Huxley predicted in Brave New World.
Solving Everything
Greene is forthcoming in his goal to fundamentally change how we approach moral problems. Remember the Tragedy of Commonsense Morality? Greene thinks we can solve this using dual-process theory. We can switch our brain to "manual mode," where cognitive control is dominant. From there, we can use utilitarianism to arbitrate our difficult moral problems.
About half the book is dedicated to this line of thinking, and if you are interested in utilitarianism, or want to get a closer look at Greene's thinking, it is quite detailed. Greene demonstrates high levels of cognitive control, and to the credit of his theory, he keeps the discussion civil. I won’t address the validity of utilitarianism in this review.
I will instead offer a cynical take on the whole enterprise via Greene himself.
[Dan] Kahan's theory predicts that people who are more scientifically literate, rather than gravitating toward the truth, will simply be more adept at defending their tribe's position, whatever it happens to be.
I.e.,
Egalitarian communitarians, as expected, reported perceiving great risk in climate change, but within that group there was no correlation between scientific literacy/numeracy and perceived risk. Likewise, the hierarchical individualists were, as expected, skeptical about the risks of climate change, and within this group, those who were more scientifically literate/numerate were somewhat more skeptical about the risks of climate change… Overall, beliefs were well predicted [not by numeracy but] by their general cultural outlooks—by their tribal memberships.
But the most damning critique of Greene's moral prescriptions is his own comments on slavery. He starts out by admitting that he, as a utilitarian, doesn't believe in fundamental rights. It is the consequences of slavery that make it wrong. But then he begins to hedge.
I'm opposed to slavery because the costs overwhelmingly outweigh the benefits. But doesn't it make you a little uncomfortable to hear me put it that way? Me, too. Thus stated, it sounds like maybe, just maybe, if someone were to come along with the right kind of argument, I would consider changing my mind about slavery. Well, rest assured that on this particular matter, my mind is closed.
He doubles down:
I'm happy to join the chorus: Slavery violates fundamental human rights!
"But," you object, "you don't really mean it!" Yes, I do. To a deep pragmatist, declarations about human rights are, when properly deployed, like wedding vows… we can appeal to rights when moral matters have been settled.
Greene sets out to give us a tool, a manual mode that can solve even the most difficult moral problems across warring tribes. It's a tool so powerful we can justify murdering a man whose only crime is wearing a backpack. But when presented with the easiest of moral problems, he tosses it aside to appease sacred tribal rights. He wants to eat his cake and have it too.
Contemporary Politics and Dual-Process Theory
Despite my skepticism for Greene’s philosophy, I love his dual process theory. Especially in graph form.
Let’s play around with it. The points on this graph were randomly generated. But if you had to label one of them as Donald Trump, which would it be? And Bernie Sanders? And Scott Alexander?
What I find is that the graph functions with surprising fidelity as a political compass. What if, as a heuristic, we say those below the line are conservative, and those above the line are liberal.
An example makes this clearer. Let's assume the dotted line represents current public healthcare spending for the very poor. Conservatives will say we should spend less than the line, because it's a waste of time and money for top doctors to treat drug addicts (who will return to the streets and continue to make bad choices). This policy is harsh—similar to pushing a backpacker in front of a trolley—but if we repress our VMPFC, we can see the logic in it. And, in a further fit to the model, if we switch it off completely, we see that taxation is theft and that the poor are a drain on society.
Liberals, on the other hand, will want to spend more on public healthcare. This is very kind of them. But at the extreme, they will say things like "you can't put a numerical value on human life." A beautiful sentiment that a functioning DLPFC tells us cannot be true.
I’m pretty happy with this model. It’s definitely missing some complexity. (There are bleeding heart conservatives, like RFK Jr vis-à-vis vaccines, and coldly calculating liberals, like the famously wrong Paul Ehrlich.) But it generally has predictive power in a lot of the major policy schisms, including crime, monetary policy, welfare, and education.
If we buy this, then our prescription is slightly different from Greene’s. It is the liberals who need to demonstrate that they have the cognitive control to push a backpacker in front of a train if it benefits the group as a whole. Conservatives, on the other hand, need to show that they find the act to be vile, and they will only do it in the most extreme of circumstances.