The Strange Relationship Between Virtue and Violence

An interview with Richard Wrangham about his new book "The Goodness Paradox."

Posted Feb 11, 2019

"Authoritative, provocative, and engaging, The Goodness Paradox offers a startlingly original theory of how, in the last 250,000 years, humankind became an increasingly peaceful species in daily interactions even as its capacity for coolly planned and devastating violence remains undiminished." 

"The Goodness Paradox is a breakthrough that deserves careful reading, thoughtful consideration, and lively debate among all those who care about our evolutionary history and the future of human morality."—Sy Montgomery, author of How to Be a Good Creature

A few weeks ago I received a landmark book by renowned Harvard University biological anthropologist Dr. Richard Wrangham called The Goodness Paradox: The Strange Relationship Between Virtue and Violence in Human Evolution. The description for The Goodness Paradox reads: "We Homo sapiens can be the nicest of species and also the nastiest. What occurred during human evolution to account for this paradox? What are the two kinds of aggression that primates are prone to, and why did each evolve separately? How does the intensity of violence among humans compare with the aggressive behavior of other primates? How did humans domesticate themselves? And how were the acquisition of language and the practice of capital punishment determining factors in the rise of culture and civilization?" Dr. Wrangham answers these profoundly important questions and much more. 

I knew The Goodness Paradox would be a riveting read, so I set aside pretty much everything else that was on my desk so I could get right into it, and I wasn't at all disappointed. The endorsements for the book from prominent scholars suggest that it is one of the most significant books ever written about the contradictory relationship between virtue and violence in human societies, and they are right on the mark. Dr. Wrangham brings to his seminal book a strong comparative perspective based not only on his long-term original research on wild chimpanzees, but also because of his mastery of wide-ranging literature on human evolution. 

I wanted to know more about The Goodness Paradox and I was thrilled Dr. Wrangham could take the time to answer a few questions about it. Our interview went as follows. 

Why did you write The Goodness Paradox and how did you come up with the title and subtitle?

For many years I have been intrigued by the problem of why, compared to other animals, humans combine particularly unaggressive social relationships (those that occur in ordinary daily life) with exceptionally high rates of killing other members of our own species (especially adults). That combination of tendencies creates the “Goodness Paradox.” If aggressiveness lies on a single scale from low to high, the fact that we are at once both highly unaggressive and highly aggressive makes no sense. 

 Andrew Bernard
A peaceful group watches nervously as Lanjo, a high-ranking male, appears and decides how to approach.
Source: Andrew Bernard

During the last two decades I became increasingly confident about the solution that I describe in The Goodness Paradox. Eventually the idea will admittedly be tested robustly by further research on domestication. So in theory I could have waited longer to publish. But research can always wait for stronger data, and in my judgment the time to change the terms of the discussion about human violence is overdue. For too long, scholars in our field have engaged in an ultimately sterile argument between the Doves and Hawks, sometimes caricatured as the “Peace and Harmony Mafia” versus the “Bellicose School”, or more politely the Rousseauians versus the Hobbesians. The solution has been hidden in plain view for decades. As biologists and psychologists have long known, aggression comes in two neurobiologically distinct forms, reactive and proactive. Humans have a very low propensity for reactive aggression, and a high propensity for proactive aggression. If we recognise the existence of these two forms, the important question shifts from “Are we nice or nasty?” to “Why did these two different tendencies evolve in their opposite directions?” This latter question leads to many fascinating ideas and implications.

My book’s subtitle is: The Strange Relationship Between Virtue and Violence in Human Evolution. This is a straightforward description of a conclusion that seems to me logical and clear but also remarkable. I believe that the reason that humans have evolved to be so relatively tolerant and calm, in ordinary face-to-face interactions, is that for more than 300,000 years our ancestors used extreme violence – in the form of capital punishment – to control those who imposed their will on others by physical aggression. As a result, there was genetic selection against those who had a high tendency for reactive aggression or even for self-interested competitive behavior. Over evolutionary time, in other words, a uniquely human form of violence (capital punishment) led to a uniquely human tendency to be morally virtuous.

How does it follow from your many years of groundbreaking fieldwork on chimpanzees? How do nonhuman animal models of virtue and violence figure into your arguments?

A critical insight is the recognition of differences and similarities in rates of aggression when we compare humans and chimpanzees. Martin Muller, Michael Wilson and I have documented rates of aggression and killing among chimpanzees in detail and compared the results to studies of humans. The result is obvious to anyone who spends time with these immensely appealing, fascinating but also disturbing apes. Chimpanzees engage in physical aggression with other group members at a frequency hundreds or thousands of times higher than humans do. Nowadays any human that got into fights as frequently as a wild chimpanzee, or a wild bonobo for that matter, would be locked up within days. So in that respect humans are far more peaceable than chimpanzees or bonobos. On the other hand the probability of a human dying by being killed by other humans, especially in war, is in the same range as the probability of a chimpanzee dying by being killed by other chimpanzees. Both species are long-lived and can die from various causes, so it is not very common for either a human or a chimpanzee to be killed by conspecifics. Nevertheless, humans and chimpanzees have similarly high rates of being killed in conflict compared to the great majority of mammals.

Andrew Bernard
Bud, a low-ranking adult male, beaten up by others.
Source: Andrew Bernard

Chimpanzees score high for both proactive and reactive aggression, whereas humans are high on the former and low on the latter. This realization raises the question about why humans are so different on the two scales.

What are some of your major messages and why should people other than "academics" care -- what are some of the "real world" applications? 

"In terms of 'real world”'applications, I hope that The Goodness Paradox will persuade readers to grant Homo sapiens a more complex psychology with respect to aggression than conventional wisdom has often allowed."

The Goodness Paradox is about behavioral evolution, and its major messages are about biology. An important conclusion is that many of a species’ characteristic features can occur because they are incidental consequences of other adaptations, rather than having their own adaptive value. This idea has often been discussed in theory, going all the way back to Charles Darwin writing about the “mysterious laws of correlation.” Now we can see it being broadly significant in many species. Specifically, selection against reactive aggression produces a suite of characteristics called the domestication syndrome, such as white patches of fur, floppy ears, short faces, small teeth, reduced maleness in skulls, smaller brains, and juvenilized adults. The Russian biologists Dmitry Belyaev and Lyudmila Trut proved this essential relationship in captivity, while Brian Hare, Tory Wobber and I have illustrated how it can happen in the wild: our example was that bonobos show the domestication syndrome in comparison with chimpanzees. But we expect that bonobos will prove to be only one of many such cases. Many species of animals must have experienced selection against reactive aggression in the wild. Whenever this has happened, we can expect elements of the domestication syndrome to appear. An interesting context for exploring this is in island populations, which are routinely found to be less aggressive than their continental cousins. This line of thinking gives us a more complex picture of evolution than the simple version that claims all traits are adaptive.

In terms of “real world” applications, I hope that The Goodness Paradox will persuade readers to grant Homo sapiens a more complex psychology with respect to aggression than conventional wisdom has often allowed. A popular concept has been that humans are born innocent and would live in peace throughout their lives if only they could escape from the perverted influences of various cultural ills such as patriarchal ideology, the privatisation of property or unequal wealth. I argue that while there is some truth in that idea, it is incomplete. In addition to having a naturally low propensity to be aggressive in ordinary social interactions, humans also have a naturally high propensity to be aggressive under other circumstances, particularly when they have overwhelming power at their disposal. The great problem with the Rousseauian vision of humans as the temperamental equivalent of floppy-eared rabbits is that if you design society on the assumption that everyone will always behave agreeably, you invite abuse by the socially dominant. History and evolutionary biology both remind us that we will always need social institutions to tamp down the effects of power asymmetries. We tear down culturally evolved protections at our peril.

Who is your intended audience?

I wrote this book for people interested in the great nineteenth-century questions about humanity: Where do we come from? Who are we? Where are we going? It resonates with the evolutionary biology of Richard Dawkins and Jared Diamond, the chimpanzee studies of Jane Goodall and Frans de Waal, research on aggression by Steven Pinker, the human evolutionary trajectory described by Dan Lieberman, the behavioral studies of Sarah Blaffer Hrdy and Michael Tomasello, the accounts of domesticated animals by Richard Francis and Lee Dugatkin, and the tracing of moral origins by Christopher Boehm. I hope that readers who appreciate those kinds of authors will find The Goodness Paradox fresh and intriguing.

Can you please say more about humans being "positively dualistic with respect to aggression" and also explain the differences between reactive "hot--aggression and proactive "cold--aggression." In your book you write that the first explains our virtue and the second our violence?

Reactive aggression is always emotional, such as losing your temper, and is therefore hard to control. It is produced in response to a threat, such as when someone insults your mother, or tries to steal from you, or endangers your life. In our daily lives we rarely see fights, and when they do happen, it is a highly notable event, a topic of conversation for days. People whose inhibitions have been loosened by alcohol, by high levels of testosterone, or by having a relatively small prefrontal cortex, are more likely to react with aggression. Still, in comparison to the routine tussling of most wild animals, rates of human conflict are amazingly low, more like a domesticated animal than a wild specie. In 1795 the great German physical anthropologist Johann Friedrich Blumenbach put it this way: “man …is far more domesticated …than any other animal.” I call humans virtuous because in this way we are so strikingly unaggressive.

Andrew Bernard
Esilom, the alpha male, arrives with an aggressive charge.
Source: Andrew Bernard

Proactive aggression is the deliberate, premeditated form that often occurs without any emotional arousal. Instead of defending against a threat, it is used to achieve a goal such as killing a rival or getting rid of someone defending a valuable resource. Proactive aggression is less common in animals than reactive aggression, but it is still widespread. Males of many species stalk and kill infants who have been fathered by other males, for example. To a large extent human warfare consists of exchanging acts of proactive aggression, in which attackers attempt to kill enemies and then escape unharmed. Intergroup aggression among chimpanzees is similar in that respect.

The neurobiology of proactive and reactive aggression has been studied best in rats and mice. The same ‘attack circuit’ is involved in both types, including the amygdala, hypothalamus and periaqueductal gray. However the parts of each brain region that are activated are different. For instance the dorsal part of the periaqueductal gray is activated in reactive aggression, compared to the ventral part in proactive aggression. The neurophysiology of aggression is less well studied in humans, but studies of the effects of drugs and interference with frontal activity indicate that aggression in humans, cats and rodents is innervated by the same evolutionarily conservative systems.

You write about what are "wild domesticates?" What do you mean by this phrase?

“Wild domesticates” is a term I use to describe species that self-domesticated without humans even being present at all. They are species such as bonobos or island animals in which the selective advantage of being less aggressive can occur for a variety of reasons. In bonobos the reason why males became less aggressive was probably because the species occupied a habitat in which females were able to form defensive coalitions so predictably that they could always form coalitions to chase and control unruly males. Islands are too small to allow top predators to survive, so populations become larger, and animals that are too aggressive expend too much time and energy in conflict. Whatever the selective pressures against reactive aggression are, the effect is that a “wild domesticate” is produced.

I admit that to call an animal a “domesticate” when they have had no evolutionary exposure to humans is confusing, since ordinarily we restrict the use of the word “domestication” to animals that live with us. However there is no other word for species whose reactive aggression has been reduced by selection. That is why I like to call species such as bonobos “wild domesticates.”

You also write, "I explain why I believe self-domestication through the selective force of execution was responsible for reducing humans' reactive aggression from the beginnings of Homo sapiens." What do you mean by this?

The beginnings of Homo sapiens can be traced to around 300,000 years ago, thanks to studies by Jean-Jacques Hublin and colleagues. Skulls from that era found at Jebel Irhoud in Morocco show the earliest sign of some of the features that distinguish Homo sapiens from other Homospecies, such as a reduced brow ridge, a less protruding face, and smaller chewing teeth. As I describe in The Goodness Paradox, these and later characteristics of Homo sapiens fit the domestication syndrome so well that they suggest that our ancestors have been experiencing selection against reactive aggression ever since our origins.

How can we explain selection against reactive aggression (or in other words, self-domestication) in our lineage? Christopher Boehm surveyed small-scale societies to find out how they control excessively violent men. The answer is clear. In the absence of prisons, police or a state apparatus, the victims of aggression start by using familiar social mechanisms. They cajole, or ridicule, or ostracise the problem-maker, or they might try to leave him on his own. Some aggressors might respond by backing down and trying to mend their ways. Others, however, are incorrigible. They laugh at their accusers, stay with them, and continue to throw their weight around. Using their personal physical strength, they steal food, rape or murder. When that happens, there is only way for the society to respond. They kill the offender. In the long term, this system would lead to an erosion of the genes underlying a strong propensity for reactive aggression. It would lead to self-domestication.

You have a chapter called "The Evolution of Right and Wrong." Briefly, what is "right" and what is "wrong" and are there cultural variations?

“Right” and “Wrong” refer to behavior that is considered appropriate or inappropriate from a moral perspective. Human morality is unique compared to animals because it is concerned with the tensions between the individual’s interest (what is best for him or her) and the interests of a social group (what is best for the group). Different human groups have different interests, so what is considered right or wrong differs accordingly. For instance in most societies it is in their best interests to prohibit cannibalism. For a boat-group of starving sailors, however, it may be in their best interests to allow cannibalism, which can therefore be regarded as morally permissible.

In my book I describe how the evolution of human moral senses is explicable by the theory that in Homo sapiens, capital punishment was used to eliminate individuals who failed to act for the good of the group. Christopher Boehm presented this idea in his 2012 book Moral Origins. In elaborating on it, I note that the “social group” that is the arbiter of right and wrong is often not the whole group of adults. Instead, it can often be merely the group of breeding men. The distinction between the “whole group” and the “male group” is important when the morally appropriate behavior serves the interests of the men rather than the group as a whole. This is a common context, and a major source of patriarchal behavior.

How do your ideas mesh with what's happening in today's world for different human societies, namely there are so many wars, and is there a general message that has global application?

Unfortunately the fact that humans have a very low propensity for reactive aggression does nothing to stop humans from having a very high propensity for proactive aggression, which is the style that predominates in war. It even seems that our low emotional reactivity has helped to promote our effectiveness at making war, since by reducing inter-individual tensions it enables us to cooperate particularly well including devising and carrying out violence. 

Recognition of a long evolutionary history of proactive violence should not be a cause for despair, however. What evolutionary theory and animal studies show us is that the use of power in the form of proactive violence is essentially cowardly: selection has favored a tendency not to commit violence if the aggressor perceives it to be personally risky. Proactive aggression is inhibited, therefore, whenever potential victims can fight back effectively. That is probably an important reason why violence against rival chimpanzees varies in its frequency among populations: it is more common in habitats where individuals are often found alone, forced by ecological exigency to take the risk of foraging solitarily. In a similar way, human societies can be at peace for decades if their power relationships with neighbors are sufficiently balanced. Danger is expected to loom when one society has exceptional force and can use it at low risk to its own members. The message is: the violence of the powerful can be deterred.

What are some of your current and future projects?

For the last few years The Goodness Paradox has kept me from writing up research results from our studies of chimpanzee behavior in Kibale National Park in Uganda. I want to go back to that for a bit! But I am also tempted to write about the evolution of patriarchy. I feel that there is more to say about why evolutionary influences have promoted patriarchy so extensively in human society, albeit to different degrees in different settings.

Is there anything I missed that you would like to tell readers?

This is an exciting time in human evolutionary studies because the genetic revolution is making ideas about similarities in the behavioral biology of humans and other animals increasingly testable. We are on the verge of understanding where we come from, and who we are, better than ever before. We are living in the middle of an intellectual revolution that began with Copernicus and will end with a truly confident vision of what makes us human. 

Thank you Richard for a highly informative and fascinating interview. I thoroughly agree with Jane Goodall's endorsement that your book is “A brilliant analysis of the role of aggression in our evolutionary history” and Sebastian Junger when he writes, “Richard Wrangham has written a brilliant and honest book about humanity’s central contradiction: that we are capable of mass murder but live in societies with almost no violence. No other species straddles such a wide gap, and the reasons are staggeringly obvious once Wrangham lays them out in his calm, learned prose. This book is science writing at its best: lucid, rational and yet deeply concerned with humanity."

Each time I go back to The Goodness Paradox I learn more and more about who we are and how we got here. I hope your book receives a broad global audience. It would be a perfect choice for many different university courses and for non-academics as well. 

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