Counting Calculi

Risen Apes

The past, present, and future* of violence

by Kevin McLaughlin

The Better Angels of Our Nature: Why Violence Has Declined
by Steven Pinker

In the Better Angels Project we will be turning all graphs from The Better Angels of Our Nature into online, interactive data visualizations.

Better Angels of Our Nature Cover

"We were born of risen apes, not fallen angels.... The miracle of man is not how far he has sunk but how magnificently he has risen."r1

-Robert Ardrey

Newsrooms pundits, university academics, and politicians all seem to agree that the world is free-falling towards hell and some institution of modernity is to blame. The wars of nation-states pile up unimaginable body counts. The profit motives of free-market capitalism drive people to greed instead of generosity. Modern reasoning turns people away from the purity of their forefathers' religions or rationalizes a sense of cultural superiority. All these prophets of doom rely on the seemingly obvious assumption that the world really is going to hell. But is it?

The Better Angels of Our Nature: Why Violence Has Declined by Steven Pinker answers with a resounding No. In the book, Pinker marshals scores of statistics on violence and unites them with his command of our evolutionary psychology and history to give a definitive account of the decline of violence throughout history. His book destroys any romantic notions about the past and demonstrates that the very institutions of modernity we often blame for our downfall are actually responsible for the decline of violence, "what may be the most import thing that has ever happened in human history".r2 In doing so, Pinker writes what may be the most important book in decades.1

Better Angels describes the decline of all forms of violence. Simple murder, wars between nation-states, rape, lynching, and even bullying are within its scope. To make sense of the decline of so many categories of violence, Pinker proposes six historical trends in the first half of the book. Some of these trends, especially the Pacification Process, took place over millennia, others, like the New Peace, are tenuously recent. To understand violence over such a long range of time and across so many different environments, Pinker must consult multiple, diverse data sets, from archaeological burial grounds, to casualty figures of world wars, to medieval etiquette manuals.2 And since it would be inadequate to suggest that violence declined simply because people became less violent, he provides exogenous causes for each historical trend. For example, the printing press made the free exchange of ideas easier, kick starting The Humanitarian Revolution.

The key to understanding the numbers behind the decline of violence is to measure violent acts as a percentage of the population rather than in absolute numbers. This may seem counter-intuitive, the fact that there are more people in the world today does not make my killing you any less wrong than my ancestor killing yours. However, Pinker is not concerned with the morality of individual acts, but rather which society you would rather live in. Anyone interested in self-preservation would chose to live in a society where 10 out of 100,000 people die violent deaths rather than one out of 100.

Armed with this understanding we can begin to debunk the myths about violence. For instance, the two world wars combined with the genocides of the first half of the 20th century seem to mock a belief in the decline of violence. The graph below shows the 21 worst atrocities in human history. Obviously, in absolute numbers, the nation-states of the 20th century were matchless in the destruction they wrought.


But when we convert the absolute numbers to rates of violence the past doesn't look so innocent. The An Lushan Revolt, a rebellion against the Tang Dynasty of China that took place from 755 to 763, killed, without the help of gunpowder, one sixth of the world's population in only seven years. In 1950, an equivalent event would have killed 429 million people, putting it in the range of a nuclear holocaust. Of course, all numbers, especially those from long ago, are estimates and subject to question. But Pinker's data doesn't need pencil point accuracy because his trends are visible in orders of magnitude so broad brush strokes will do.

However, many critics of Better Angels have completely rejected his claim that we should measure rates of violence instead of absolute numbers. For instance, the theologian David Bentley Hart wrote that Pinker's alleged decline in violence is really a "continual and extravagant increase in violence that has been outstripped by an even more exorbitant demographic explosion". Let's forget for a moment that battle deaths, municipal homicides, and all forms of crime are always measured as rates,3 and assume that Hart's criticism is correct, that the decline in rates of violence is entirely due to population growth. Violence, like sex, requires at least two participants, a murderer and a victim. So Hart's demographic explosion theory would still need to explain why millions and billions of people today decided to kill less than their ancestors. The theories in Better Angels, after all, apply just as well to a "rise in peace" as a "decline of violence".

The second half of Better Angels examines our human nature to find out what in our evolutionary psychology made us so violent in a state of nature but peaceably sensitive to the historical trends proposed in the first half of the book. Humans, left on their own "will not fall into a state of peaceful cooperation, but nor do they have a thirst for blood that must regularly be slaked."r4 Instead human violence is triggered or checked by a complex combination of our psychological traits and environmental factors. Pinker proposes Five Inner Demons, five traits and factors that make us more violent, and Four Better Angels, four traits and factors that make us less violent. Pinker describes why each demon and angel evolved. For instance, dominance is the "willingness and an ability to defend [oneself] against depredations"r5 and evolved to scare others away from a fight in a world without the police. Understanding the specific evolved mechanisms for violence lets us see what caused the influence of our demons to drop and that of our angels to rise.

Of the factors that Pinker proposes for our angels' rise, three in particular stand out because they are often blamed for everything that is wrong with modernity. They are: governments - what Pinker terms "Leviathan", free-market capitalism - "Gentle Commerce", and reason - or "The Escalator of Reason".

As we saw above, the supposed unprecedented levels of violence perpetrated by modern nation-states are really illusions caused by failing to index death tolls to population. However, there is a deeper reason why governments, especially modern nation-states, actually decrease violence. It begins with the Hobbesian Trap.

The Hobbesian Trap is a dilemma first described by Thomas Hobbes in the 17th century resulting from life in a state of nature, ie the "anarchy of hunting, gathering, and horticultural societies".r6 The dilemma goes like this: in a state of nature I can't be sure that you won't kill me to take my food. So, even if I'm a peace-loving hippie otherwise, I have an incentive to kill you before you can kill me, in other words to launch a preemptive strike. The trouble is, even if you're a meditating yogi, you have the same reason to kill me first. Thus any hint of attack or perceived slights can set off a cycle of violence between you, me, and potentially our respective kin and tribes later. Hence the "war of all against all" Hobbes described and the Hobbesian Trap that makes life in a state of nature "nasty, brutish, and short".r7

Hobbes also proposes the solution to the trap in his magnum opus Leviathan. To solve The Hobbesian Trap, you and I must defer authority to a disinterested, powerful, third party - a Leviathan. This Leviathan breaks our trap by saying "Author if you kill Reader, I will destroy you. And Reader, if you kill Author, I will destroy you. And since I'm more powerful than both of you, there's nothing either of you can do to stop me." Since Leviathan will kill whoever attacks first, our incentives to preemptively strike each other vanish and we can go back to our peace-loving hippie and yogi ways.

Of course the Leviathan is government.4 Early governments were small chiefdoms, we might call them little Leviathans, and they successfully ended violence within their respective groups, the "war of all against all". But the logic of The Hobbesian Trap that gives individuals a reason to preemptively strike in a state of nature applies equally well to the little Leviathans, giving them a reason to preemptively strike each other. So while violence within groups dropped off, violence between groups, like the city-states of Greece and later the fiefdoms of Europe, increased.

Cover of Leviathan

Throughout two of Pinker's historical trends, the Pacification and Civilizing processes, these little Leviathans coalesced into larger and larger groups, decreasing the number of groups that could war with one another.5 According to Pinker, Europe had 5,000 independent political groups in the 15th century, 500 in the 17th, 200 in the 19th, and fewer than 30 in 1953.r9 As the Leviathans got bigger and stronger, rates of violence plummeted, as shown in the graph below comparing homicide rates of pre-state and Western European societies. Pinker finds that living within a Leviathan decreases your chances of being a victim of violence fivefold.r10


The largest Leviathans today are massive, complex nation-states. Since the advent of nation-states, the frequency of small city-state wars like those of ancient Greece, and the feudal raids of medieval Europe have fallen to zero in areas controlled by these massive Leviathans. Of course, it takes modern nation-states to wage world wars. But as we saw above, the death tolls from world wars can be deceptively small compared to the atrocities of the past. And the countless small wars and raids that didn't make the history books can, when combined, pile up an unimaginably high wall of bodies. Furthermore, it doesn't take world wars or even feudal raids to send rates of violence to imponderable heights. Simple murder will do. Pinker finds that even today "homicides outnumber war-related deaths, even if one includes the indirect deaths from hunger and disease".r11 So while modern Leviathans are capable of wreaking havoc on a horrific scale with machine-like efficiency, on the whole, they, and their smaller ancestors, have decreased violence more than anything else in human history.

A Leviathan solves The Hobbesian Trap by threatening force with force. Gentle Commerce, by contrast, requires no threats for its contribution to declining rates of violence. Recall that The Hobbesian Trap requires that both you and I to be ready to defend ourselves and our resources at all times. But suppose that I have some food and you have some warm blankets. Now I really don't want to freeze tonight so I have two options, I can attack you and take your blankets by force, or I can trade some of my food for your blankets. Of course, if I attack successfully, I get more food and more blankets, but I also might fail and get injured or killed in the attempt. If I trade, I give up some of my food but on balance it's probably a safer bet. Now the same logic applies to you in reverse, so we're both better off trading than fighting. Hence, unlike fighting, trading is non-zero sum game that we can both win.6 Since you are better off trading with me, I have reason to think you are not going to kill me and thus less reason to preemptively strike you. And, again, the logic applies in reverse. If we become regular trading partners, we may even begin to trust each other. Then our Hobbesian Trap will be completely broken.

What expanded trade from the simple barter system described above to the full blown economies we enjoy today was a division of labor. First described by Adam Smith in The Wealth of Nations in 1776, a division of labor makes it possible for individuals to specialize in producing one good with less resources. For instance, if a cobbler doesn't have to worry about growing food for himself, he can devote more time to perfecting his shoemaking technique, thus producing many more shoes over his lifetime. Of course, if the cobbler is not to starve to death while making shoes, he must be able to trade his shoes for food, and anything else he needs. As the cobbler and his trading partners continue to specialize and trade, they become more and more reliant on one another and their incentives for violence decline.

Throughout Pinker's Civilizing Process an increasing division of labor shifted societies away from the agricultural land-based economies like those of feudal Europe, to labor-based ones where emphasis was placed on finding tools and techniques to make more goods with less resources. Since there is only a finite amount of land, the only way to increase your wealth in a land-based economy is to conquer more of it. However, in a labor-based economy more and more goods can be produced, making trade vastly more profitable than conquest. Of course, the newly generated wealth was (and is}} distributed unequally but everyone still benefited from the rising tide of goods. As Adam Smith said "the accommodation of an European prince does not always so much exceed that of an industrious and frugal peasant, as the accommodation of the latter exceeds that of many an African king".r12

As we saw with The Leviathan, countries are subject to the same Hobbesian Trap as individuals. And, like The Leviathan, the pacifying effects of Gentle Commerce apply with equal force to countries as they do to individuals. Pinker finds that countries engaged in multiple forms of international commerce - trade, openness to foreign investment, and free market economies - are less likely to go to war with one another, irrespective of other similarities like forms of government, or economic and military might.r13 Multinational corporations, as the name suggests, depend on multiple nations for their natural resources, labor, and customers. Openness to foreign investment requires that the countries involved depend on each other to progress, instead of standing in each other's way. And a free market economy where resources and production are controlled by the voluntary decisions of all its constituent members7 and not by dictators or government bureaucrats, cannot easily be forged into a war machine or bent to the extermination of one group as with Hitler's Germany, Stalin's Russia, and Mao's China.

Now, all these economic factors incentivize peace because it is profitable not because it noble. But that is the point. Ideally people would support peace regardless of self-interest, but aligning economic interest with peace has proven time and time again to be much more effective than relying purely on good-will. Like our food and blanket trading ancestors, modern economies allow agents to act out of self-interest and profit by creating goods and services that help others rather than destroying them in wars of conquest. A profit motive does not weaken peace but rather reinforces it. In the words of the peace researcher Nil Petter Gleditsch, the modern economy allows people to "make money, not war".r15

Both The Leviathan and Gentle Commerce developed unintentionally and over centuries. Pinker's final development, The Escalator of Reason, an idea he borrows from Peter Singer, is much more recent. Reason let's us imagine abstract hypotheticals and derive conclusions based on logic rather than our own subjective vantage points. It lets me see that while I have my own subjective perspective and interests, "others have similarly subjective perspectives, and that from ‘the point of view of the universe' my perspective is no more privileged than theirs".r16 In a Hobbesian Trap, I must argue from this universal perspective or common point of view, if I am to convince you not to hurt me. Since from the universal perspective there is no logical difference between the pronouns you and me, as soon as I say "it's bad for you to hurt me", I'm committed to "it's bad for me to hurt you". Reason thus requires us to pursue universal interests. The Escalator of Reason is the continuing logical extension of these universal interests to include more and more people.

So why did humanity take so long to reason its way out of the Hobbesian Trap? For one thing, the trap requires that both agents reason their way out simultaneously,8 not likely in an anarchic state of nature. For another, like theoretical physics, it requires advanced cognitive tools, like symbolic replacement and set theory, that are unnatural and must be learned. These advanced cognitive tools only developed recently in the human epoch and even then only in fits and starts.

The first major fit of reason to cause a large decrease in violence occurred in the 17th and 18th centuries during the Enlightenment. Pinker calls this historical trend The Humanitarian Revolution. Made possible by the stability and prosperity created by stable governments and commerce, and fueled by the wide availability of books hot off the printing press, the Enlightenment saw an explosion of great thinkers. Hobbes and Smith mentioned above were joined by, among many others, Cesare Beccaria, who argued that punishment ought to be proportional to the crime, and Immanuel Kant,whose prescient essay Perpetual Peace showed how democracy and Gentle Commerce could end wars between nation-states. By recognizing the flaws in human nature and designing ways to mitigate them, these thinkers destroyed the justifications for ridiculous superstitions like witch burning, cruel and unusual punishments like breaking on the wheel, and pointless wars by glory-seeking monarchs. Of course, even without their justifications, some of these practices lived on (and some still do}}, but after The Escalator of Reason got started, most could not survive for long.

The second fit of reason in Pinker's book is The Rights Revolutions. The Rights Revolutions began with the Civil Rights movement in the United States. Like The Humanitarian Revolution, this second reason revolution likely started because of a huge increase in communication technologies like televisions that could show real time footage of fire hoses and attack dogs used against peaceful civil rights protesters. Whatever the cause, once The Escalator of Rights got started, its logic was impossible to stop. If white men could not be denied their rights, then why blacks? If not blacks, then why women? If not women, then why homosexuals? And, perhaps next, if not homosexuals, then why animals? That's not to say modern countries are free from all forms of bigotry, but the decline of bigotry-inspired laws and violence has been stunning.

Now pundits, professors, and politicians don't typically argue that reason is directly to blame for our downfall. But they do argue in favor of concepts that are incompatible with reason. The religious right often argues that we have lost our traditional moral values. Surely these values do not include the burning of witches or lynching of African Americans, but they used to. While it's true that religion has often inspired anti-violence movements like the abolition of slavery and civil rights, it also inspired the opposition to these movements.9 With religion on both sides, reason held the balance.

Consider a current traditional value, traditional marriage. Those opposed to gay marriage usually cite the Bible, while the Supreme Court decision that struck down traditional marriage laws referenced the secular Constitution, reasoning that if marriage could not be denied to whites or interracial couples, then it could not be denied to homosexual couples. Furthermore, religious conservatives might be surprised just how much enlightenment reasoning has seeped into their religion. Afterall the Bible does not say "thou shalt not allow gay marriage". It says "If a man lies with a male as with a woman.... they shall surely be put to death".r17 I doubt all 39% of the Americans who oppose gay marriage are prepared to make gay sex a capital offense.

While the right argues for traditional moral values in spite of reason, moral-relativists on the left argue that reason is actually just a rationalization for imposing one culture's value system on another. It's true that all humans are imperfect reasoners with biases and these biases have often caused them to rationalize oppression through pseudo-science like craniometry. But reason is what allows us to separate the pseudo-science, like craniometry, from the real science, like the harm caused by genital mutilation. The process is long, because overcoming our innate evolved biases is difficult. But "crude tools can be used to make refined tools".r18 As The Escalator of Reason continues we can better distinguish between right and wrong. As the declines of witch-burning, black lynching, and gay bashing show, we have refined our tools of reason, and we can continue.

The history of violence shows that we should be wary of appeals to a by-gone age when the world was peaceful, when people didn't act out of self-interest, or when they were innately moral.10 We are not fallen angels. Human beings evolved in a state of nature when The Hobbesian Trap made a willingness to commit violence adaptive and often necessary for survival. On an evolutionary scale, we have only just recently emerged from this state of nature and these evolutionary traits remain with us, prompting us to violence. They are Pinker's inner demons, a part of our DNA, our human nature. The danger of taking a rose-colored view of the past, either by failing to account for relative death tolls or selective memory or a noble savage opinion of our ancestors, lies in overlooking the gains we have made and ignoring or even abandoning the institutions that have made modernity better than the past.

Because things have gotten better. Modernity is far from perfect but its foundations have decreased violence to levels that would have seemed utopian 1,000, 100, or even 50 years ago. But it needn't stop here. Pinker repeatedly emphasizes that Better Angels is not a prediction that violence will continue to decline or that it will never return to previous, horrific levels. But the implication is clear. As long as we are honest about the past and willing to look unflinchingly at our inner demons, we can continue to build a world that tips the scale more and more in favor our better angels. Then the naked ape can continue to rise.

1. Bill Gates, Mark Zuckerberg, and Peter Singer think so. ^

2. One medieval etiquette manual chastises its readers to refrain from "fouling the staircases, corridors, closets, or wall hangings with urine or other filth". Our ancestors weren't just violent, they were gross.r3 ^

3. Attributing the decline in rates of violence to pure population growth is as innumerate as attributing a decline in poverty to inflation. ^

4. Hobbes thought of government as an "Artificiall Man [sic] in which the Sovereign (usually a King) is the "Artificiall Soul", Magistrates the joints, reward and punishment the nerves, and laws the "reason and Will"r8. You can see in the book's frontispiece shown above that the man holding the sword and crosier, the Leviathan, is composed of many small people, visualizing how the "Artificiall Man" was composed of all the people in the commonwealth. ^

5. This is a major reason why Hamilton and Madison argued for a strong central government in The Federalist Papers. See Federalist Number 20. ^

6. This is how reciprocal altruism evolved. ^

7. This is Adam Smith's "Invisible Hand".r14 ^

8. It only works if I know that you won't attack me, because you know I won't attack you, because you know that I know that you won't attack me, ad infinitum. Just this reasoning out this sentence took a long time. ^

9. Many a southern slaveholder considered it his Christian duty to keep slaves. ^

10. Like appeals to "make America great again". ^

r1. Robert Ardrey African Genesis: A Personal Investigation into the Animal Origins and Nature of Man ^

r2. Steven Pinker, The Better Angels of Our Nature, Page 1, Kindle Location 151 ^

r3. Steven Pinker, The Better Angels of Our Nature, Page 69, Kindle Location 1713 ^

r4. Steven Pinker, The Better Angels of Our Nature, Page 483, Kindle Location 10656 ^

r5. Steven Pinker, The Better Angels of Our Nature, Page 515, Kindle Location 11389 ^

r6. Steven Pinker, The Better Angels of Our Nature, Preface XXIV, Kindle Location 212 ^

r7. Thomas Hobbes, Leviathan, Kindle Location 1425 ^

r8. Thomas Hobbes, Leviathan, Kindle Location 47 ^

r9. Steven Pinker, The Better Angels of Our Nature, Page 74, Kindle Location 1841 ^

r10. Steven Pinker, The Better Angels of Our Nature, Page 51, Kindle Location 1423 ^

r11. Steven Pinker, The Better Angels of Our Nature, Page 221, Kindle Location 4968 ^

r12. Adam Smith, The Wealth of Nations, Kindle Location 212 ^

r13. Steven Pinker, The Better Angels of Our Nature, Page 287, Kindle Location 6398 ^

r14. Adam Smith, The Wealth of Nations, Kindle Location 6995 ^

r15. Steven Pinker, The Better Angels of Our Nature, Page 288, Kindle Location 6424 ^

r16. Peter Singer, How Are We to Live?, Page 226 ^

r17. King James Bible, Leviticus Chapter 20 verse 13 ^

r18. Peter Railton, The Stone Reader: Modern Philosophy in 133 Arguments, Kindle Location 3939 ^