Intro. [Recording date: January 28, 2026.]
Russ Roberts: Today is January 28th, 2026, and my guest is philosopher and author, Hanno Sauer. His latest book, and the subject of today’s episode, is The Invention of Good and Evil: A World History of Morality. Hanno, welcome to EconTalk.
Hanno Sauer: Thanks for the invite, Russ.
Russ Roberts: Your book is quite expansive, teeming with thought-provoking ideas and traversing a vast timeline of human history and behavior. We’ll do our best to distill some of its key concepts today.
Your opening reminds me strikingly of Adam Smith’s Theory of Moral Sentiments. Smith famously begins with: “How selfish soever man may be supposed, there are evidently some principles in his nature, which interest him in the fortune of others, and render their happiness necessary to him, though he derives nothing from it except the pleasure of seeing it.” Much of his work grapples with the question: Why do we sometimes act against self-interest? Not unselfishly—let’s not use that term—but rather, why do we engage in behavior that appears altruistic?
Your book poses a similar question early on:
The fact that cooperation is unlikely can be formulated as an explanatory problem in evolutionary theory: how did evolution manage to create altruistic or cooperative tendencies, even though—apparently, at any rate—these tendencies inevitably reduce our reproductive fitness? How could it ever be beneficial for me to help someone else? How could it ever be worth subordinating my self-interest for the well-being of the community? [italics in original]
Hanno, your work attempts to tackle this profound question. While your answer is likely extensive, can you provide us with a concise summary?
Hanno Sauer: Absolutely, Russ. I have a deep appreciation for Adam Smith—he was an extraordinary writer and philosopher, and his economic theories are undeniably top-notch. I welcome that comparison.
At a fundamental level, my book grapples with a sort of reverse theodicy problem. In pre-Darwinian eras, under a theistic worldview, one needed to reconcile the existence of evil and suffering with an all-knowing, benevolent deity. How can we make sense of the suffering endured by innocents amidst divine goodness?
Russ Roberts: Earthquakes.
Hanno Sauer: Exactly. Now, transitioning to a naturalistic Darwinian perspective, the default assumption becomes a harsh “nature, red in tooth and claw.” It invites a worldview where everyone is selfish, and sociopathy reigns supreme. Yet, we must grapple with the existence of friendship, heroism, love, altruism, and sacrifice. Where do these virtues emerge from?
Adam Smith and many others recognized this tension. On one end, we possess instincts that are selfish and antisocial, but on the other, we exhibit friendship, altruism, and cooperative tendencies. Understanding their origins is crucial.
Interestingly, a solid answer to this question didn’t emerge until the latter half of the 20th century, when evolutionary biologists paired with economists began to explore the returns of cooperative behavior. Concepts like inclusive fitness, reciprocity, and the means through which cooperation can thrive in a morally indifferent Darwinian world started to take shape.
Russ Roberts: Indeed. These insights include the notion, as articulated by Dawkins, that one’s genes drive such behavior. For instance, if your brother shares your genes, it might be evolutionarily advantageous to risk your life to save him—or perhaps even for your cousins if the stakes are high enough. However, your treatment of these ideas is intriguing, yet it feels like part of a larger narrative. Why is that, and what do you propose as a more comprehensive explanation?
Hanno Sauer: You’re correct. Identifying why cooperation poses an explanatory challenge is one thing, but it leads to another set of issues unique to humans. We are an anomaly in the animal kingdom. Our capacity for cooperation is exceptional. We have, over extensive periods—spanning from proto-human to modern times—scaled our cooperative efforts in ways that other species do not.
Consider chimpanzees: they may cooperate in small groups of a few dozen, but they don’t form societies of thousands or millions. Imagining millions of chimpanzees working together is almost like a science fiction horror story—an uncanny notion given their nature.
Some animals, like certain insects, accomplish large-scale cooperation, but they follow genetically predetermined paths. In contrast, humans possess a remarkable adaptability, allowing us to thrive in various social structures. We can exist in small hunter-gatherer groups while also engaging in global trade, interacting with people from diverse cultures across the globe. This ability to cooperate with billions—often without direct awareness—is uniquely human.
The essence of my book is to explore how we have expanded our institutional toolkit, facilitating this large-scale cooperation from small groups to the contemporary era, where billions of individuals collaborate, often unwittingly, with others from distant lands.
Russ Roberts: What evolutionary pressures led to this remarkable outcome for humans as opposed to other animals?
Hanno Sauer: There isn’t a single explanation, but I weave together various mechanisms that enable us to scale up cooperation. As groups grow from small, genetically-related units interacting face-to-face to larger communities, we must introduce new methods to stabilize cooperation, which becomes increasingly fragile with more members.
Think about a camping trip with six family members versus one involving 60 or 600. The demands on division of labor, norm enforcement, and logistics differ vastly. When individuals in larger groups shirk their roles, cooperation can quickly unravel.
Thus, I dedicate a chapter to the concept of enforcement and social sanctions, ranging from mild reprimands and gossip to extreme measures like capital punishment, examining their role in our self-domestication as a species. We can be likened to golden retrievers in the primate world—docile and norm-conformist. Our evolutionary path has seemingly softened our aggression, especially towards our in-group.
The question then arises: how did we evolve in this manner? My hypothesis, supported by evidence, is that we systematically eliminated the most aggressive members of our tribes over generations. By removing the top 10% of the most violent individuals, we effectively reduced overall aggression within our population. This self-domestication process served to stabilize cooperation and support the scaling of our groups.
Russ Roberts: The concept of self-domestication and the role of punishment fascinates me, even if it seems a bit hard to swallow. Humans are hardly a docile species. I sometimes consider an alternative theory about how our actions shaped our gene pool: alpha males historically had multiple mates while those unable to attract partners may have ventured into unknown territories, akin to Vikings seeking fortune and partners through conquest. Perhaps we are descendants of both the subdued and the adventurous. What are your thoughts on this narrative?
Hanno Sauer: This scenario certainly holds some truth. Humans can be quite violent, capable of coordinating violence and forming coalitions for raiding. The primordial warfare likely consisted of ambush tactics rather than traditional battlefield confrontations. These violent tendencies have undoubtedly left their mark on our genetic makeup.
The question remains—did one process overshadow the other? The self-domestication dynamic appears to pertain more to in-groups, while violent tendencies are often directed outward. This “us versus them” mentality is a significant aspect of our moral psychology.
Russ Roberts: Yet, as you point out, these violent urges often transcend their original targets. You present a striking line:
One of humanity’s greatest moral developments was delighting in cruelty. It was all the more difficult to unlearn this lust for cruelty after it had fulfilled its purpose.
Can you explain these sentences? Why would such a delight in cruelty be considered a moral development?
Hanno Sauer: In contexts where enforcing social norms is paramount, a disposition towards violence can be advantageous. Just as enjoyment can motivate reproduction, an inclination towards violence can serve to deter transgressions. While this does not justify violence today, it highlights an evolutionary adaptation that was beneficial under certain circumstances.
However, once the immediate challenges were addressed, this propensity for cruelty may have become an evolutionary hangover, lingering in our psyche even when impractical. In contemporary societies, we may not require much violence to enforce cooperation, yet atavistic instincts can resurface, particularly in response to egregious crimes, prompting punitive reactions. Understanding the origins of these impulses could help us navigate their appropriateness in modern contexts.
Russ Roberts: Your assertion—that the source of this so-called lust for cruelty is an evolutionary remnant of a positive impulse—is quite unconventional. You argue that it stems from a need to punish free-riders, those who exploit group norms for personal gain. While other forms of punishment exist, none are as effective as violence, particularly when it comes to dealing with tyrants. This need for a punishment mechanism seems to have negative externalities in our behavior today.
Hanno Sauer: Exactly. I agree with your assessment. Some moral transformations may represent improvements at certain historical junctures, despite their unpleasantness when viewed through a contemporary lens. The evolution of punishment and cruelty exemplifies this concept—it served as a necessary tool for social order but now poses challenges.
As human groups expand, the necessity for enforcing social norms intensifies. Experimental studies in economics reveal that cooperation often falters without the prospect of punishment. The presence of punitive measures can stabilize cooperative behavior, although we wouldn’t idealize this as the preferred state of humanity.
Collective action problems persist, threatening social cooperation, thus necessitating some form of enforcement. While we prefer a balance of incentives over sanctions, complete absence of social controls is unrealistic.
Russ Roberts: Let me take a moment to critique economists. Gary Becker, my former advisor, often advocated for significant punishments with a low probability of detection, arguing that the expected value of punishment could deter crime while minimizing enforcement costs. This approach can be morally troubling, as it implies punishing innocent individuals to deter a broader range of offenders, which can clash with our sense of justice.
Hanno Sauer: I appreciate your perspective, but I must express my disagreement on this specific point. While I may not be fully current on this topic, my understanding of the evidence suggests that effective deterrence is achieved through a high likelihood of detection, even with milder punishments. A society where the chance of getting caught is high—even with moderate consequences—proves to be more effective than the opposite scenario.
Russ Roberts: Well, I certainly don’t keep up with the latest research, so feel free to elaborate.
Hanno Sauer: Based on my last review of the evidence, it appears that certainty of apprehension is more motivationally disincentivizing than harsh penalties coupled with low detection probabilities. Individuals who contemplate criminal actions often lack prudence, making them less susceptible to rational economic deterrence methods.
Russ Roberts: That’s a fair point, for sure.
Hanno Sauer: The concept of punishment can be likened to Gordon Tullock’s provocative suggestion: to enhance road safety, one might as well install a dagger in the steering wheel. While it may deter reckless driving, it could also deter driving altogether. This notion highlights the costs associated with excessive punishment.
Russ Roberts: Before we wrap up, I want to highlight a point that resonates with my listeners. Quoting Smith, “Man naturally desires, not only to be loved, but to be lovely.” We are inherently wired to care about how others perceive us, striving not just for love but for genuine honor.
Your observation about gossip and rumors as pivotal in our evolutionary history is particularly striking. You suggest that language may have originally evolved for social communication about others’ behaviors, which aligns with Smith’s insights into our reputation.
Hanno Sauer: Absolutely, Russ. We are motivated not just to be loved but to be worthy of that love. In most cases, these impulses align; the best way to be loved is to genuinely embody goodness. Attempting to appear virtuous without authentic intent often leads to appearing manipulative.
This paradox extends to altruism: if one aims to seem moral directly, they risk coming across as calculating. However, if the focus is on genuinely caring for others, the moral disposition becomes authentic, fostering appreciation from others.
The evolutionary process has equipped us with the capacity for genuine concern, rooted in a strategic rationale that aligns with our moral dispositions. Frans de Waal’s veneer theory of morality posits that altruism is superficial; however, I believe that our altruistic dispositions run deeper, even if underlying motives may reflect a selfish gene rationale.
Russ Roberts: The authenticity of our actions indeed serves as a more effective signal than superficiality. Herb Kelleher, the former CEO of Southwest Airlines, exemplified this by working alongside employees during the holidays. It was a powerful statement of solidarity, and he likely enjoyed it. Other CEOs might shy away from such acts because they’d have to feign enjoyment, while Herb genuinely embraced it.
Hanno Sauer: That’s a great point. CEOs who rise through the ranks and understand the company culture are more credible when engaging in such acts. A well-known chef, for instance, employed a façade of authenticity by arriving in full uniform to greet patrons, but this often backfires. People are highly attuned to deception and resent manipulative behavior.
In essence, authenticity resonates more profoundly than pretense, fostering genuine connections and trust.
[More to come, 32:42]
