Life in the state of nature was less violent than you might think. Most of our ancestors avoided conflict. But this made them vulnerable to a few psychopaths.
We are naturally a highly violent species with a thin veneer of civilization that masks a brutal proclivity for violence – or so many people think. In the seventeenth century, Thomas Hobbes said that human life without government is ‘solitary, poore, nasty, brutish, and short’. William Golding’s novel, The Lord of the Flies, which won the Nobel Prize for literature in 1983 and many of us read in school, suggests that boys will rapidly descend into mob violence and brutal cruelty without oversight from authority. To know whether this is true, we need to understand the rates of violence among our ancestors.
There is longstanding disagreement on this issue among scholars: many hold the cultural assumption that humans are by nature bellicose, but there is also a ‘noble savage’ camp that believe the opposite. Stephen Pinker’s influential 2011 book The Better Angels of Our Nature tipped the scales by using a data-oriented approach to demonstrate that prehistoric people tended towards extremely high violent death rates, with average rates of violence higher than during the peak years of World War Two.
However, Pinker’s data also showed that prehistoric hunter gatherers seem to have been less violent than prehistoric agriculturalists. This is of critical importance in understanding human history because for 96 percent of our evolutionary history, we were hunter gatherers.
Comprehensive new research has emerged with much more archaeological data on violence in prehistory. Analysis indicates that prehistoric hunter gatherers were considerably less violent than the orthodoxy previously held. This finding also seems to be borne out by ethnographic data on modern hunter gatherers with lifestyles relatively similar to their prehistoric ancestors.
Hunter gatherers were not non-violent noble savages by any stretch of the imagination. They were relatively violent when compared with modern standards and even when compared with rates of violence experienced by other primates and mammals in general. However, we think this is primarily because human conflict is so lethal, not because it happens so often. On the contrary, hunter gatherers typically exhibit non-violent norms, with amoral and atypical sociopaths accounting for a disproportionate share of violence, just as in our own societies today.
Understanding this matters. Our extraordinary capacity to inflict lethal violence on each other is normally held in restraint by the natural aversion most people have to violence. If we fail to cooperate, we are vulnerable to falling into vicious cycles of violence that don’t benefit anyone. But we should be more optimistic about our capacity for peacemaking. Despite living in states of political anarchy, hunter gatherers were normally able to cooperate and exist peacefully together.
The debate over hunter gatherer violence
For the first 290,000 years of our species’ approximately 300,000 year history, everyone was a hunter gatherer. In The Better Angels of Our Nature, Steven Pinker argued that hunter gatherers were extremely violent. Better Angels claims that at least 14 percent of prehistoric hunter gatherers died violently. This equates to a violent death rate of at least 420 per 100,000 people per year, using data on typical hunter gatherer mortality rates.
This is a much higher rate of violence than almost anywhere in the modern world in the twentieth and twenty-first centuries. To put it in perspective, global deaths from all types of violence between 2004–21 were around 8 per 100,000 people per year. Even the most violent cities in the world today, in Northern Brazil, South Africa, and on the Mexican side of the US-Mexico border, have murder rates of only around 100 per 100,000 per year.
The implication in Better Angels is that the human mind evolved and developed in a world plagued by constant, endemic violence.
Our 2022 study examined both the ethnographic data – contemporary studies of groups that existed until some modern contact – and archeological data on hunter gatherer violence, much of which comes from data gathered after the publication of Better Angels. We reviewed quantitative estimates of rates of violence in ethnographies, filtering for groups that are most representative of our pre-agricultural ancestors. Our archeological estimates are based on reanalyzing a dataset developed by Gomez et al. (which was released after Better Angels was published and has dozens of extra samples), which attempts to measure rates of violent death by looking for evidence of trauma to skeletal remains. Our study produced estimates for lethal violence around four times lower than Pinker’s figures.
Prehistoric hunter gatherers seem to have been somewhat more violent than the twentieth-century average (which Pinker considers to be the least violent century so far, despite the world wars), but not dramatically so. And this is despite these societies lacking any of the modern state’s apparatus for managing violence: no code of law, no judges, no police, and no sophisticated healthcare.
Building on Better Angels
We think that our data on prehistoric hunter gatherer violence is an improvement on previous estimates for several reasons. Pinker, whose work we greatly admire, generously reviewed our study, writing that it ‘will surely be the standard reference for this issue for years to come.’
Firstly, our dataset is more comprehensive. Drawing on work published after Better Angels, our archaeological dataset includes around 150 prehistoric hunter gatherer sites, compared to the 21 sites in Pinker’s source, and our ethnographic dataset draws on data from several modern hunter gatherer studies that Pinker’s source didn’t include.
Secondly, Pinker’s main focus was to compare levels of violence in state and non-state societies. He does not specifically target the question of violence among ancestral hunter gatherers, despite the fact that his data is regularly used in this way by others.
For this reason, Pinker’s archaeological dataset included a number of sites from non-state agricultural societies, which we excluded from our dataset.
Moreover, an important challenge when interpreting evidence from ethnographies of modern hunter gatherers is determining which groups are likely to be representative of hunter gatherers who would have lived before the invention of agriculture. For instance, Pinker includes data on the Ache, Amazonian hunter gatherers from Paraguay. Pinker’s source suggests that 30 percent of Ache deaths were due to warfare: an enormous number. Ethnographies of Ache violence appear to lend weight to this. Consider the following from Pierre Clastres, an ethnographer who studied the Ache Gatu. Clastres describes the Gatu’s struggles against the ‘white men’ and rival groups of Ache, such as the Kyravwa, who ate human fat. On one expedition, the Gatu surrounded a Kyravwa band at dawn.
Almost all the Kyravwa were killed and their women captured. There was a large feast and the . . . Gatu divided up the wives of the conquered men. [The chief] took three young ones for himself.
However, we excluded data on the Ache because they are not deemed to be a good analog for pre-agricultural hunter gatherers by anthropologists. In Clastres’ account, the Ache Gatu are said to be fighting ‘the white men’. In fact, most of the violent Ache deaths in the source were inflicted by loggers with guns – not something pre-agricultural hunter gatherers would have had to contend with.
To avoid these problems, our ethnographic sample includes only those groups classed as plausible analogs for pre-agricultural hunter gatherers, using criteria developed by the anthropologist Christoper Boehm. This data includes only groups who relied solely on hunting and gathering, were economically independent, politically egalitarian, and spatially mobile, and excludes groups who were only studied long after sustained contact with agricultural or state societies. (We suspect some of the hunter gatherer groups in our archaeological study, by contrast, will have been sedentary and inegalitarian, though we cannot know for sure.)
For these reasons we feel that the estimates in our study improve on past estimates in Better Angels and other sources.
Although we think that our study advances the state of knowledge, it must be said that both the archaeological and anthropological (ethnographic) evidence are unusually shaky. The archaeological record for the pre-agricultural period is extremely sparse, and the anthropological evidence is limited and geographically biased. Nevertheless, there are enough signals in the data to allow us to identify trends, features, and patterns.
Warfare before agriculture
It is widely assumed that we are an innately warlike species and that our ancestors lived in a world of endemic conflict with rival groups.
A classic example is the influential book Demonic Males: Apes and the Origin of Human Violence by anthropologist and primatologist Richard Wrangham, who argues that human males have an innate, pronounced propensity for lethal, coalitionary violence against rival groups. He believes that males strategically and rationally use violence to gain resources from and out-compete their neighbors. In this theory, this is the primary reason for the relatively high rates of lethal violence in our species.
However, our data suggests that endemic warfare was not the norm for prehistoric hunter gatherers. Rather the incidence of warfare was highly variable, indicating a complex balance between war and peace among our ancestors.
For example, Mervyn Meggitt’s ethnography Desert People describes attacks on the Walbiri, a group of Australian Aborigines, by another group, the Warramunga:
These were raids undertaken to combine hunting for sport and the abduction of women. Often, too, the raiders were simply spoiling for a fight. They were met with force, and deaths occurred on both sides. Walbiri war-parties would then invade the Warramunga country in retaliation. If they were able to surprise the enemy camps and kill or drive off the men, they carried away any women they found.
There is no doubt that hunter-gatherer warfare exists, as demonstrated in these sorts of accounts. On the other hand, consider this description of relations with another neighboring group:
The Yanmadjari occupy a special place in the affections of the Walbiri, who regard them as “half Walbiri and one people with us”. The two tribes have a long common boundary; they have always traded together; they share totemic ceremonies, myths and tracks; and intermarriage frequently occurs . . .
Yes, the Walbiri fought the Warramunga and another group, the Waringari and regarded both as traditional enemies. However, these conflicts seem to have been sporadic, and Meggit mentions at least 11 other neighboring groups that the Walbiri were on generally peaceful terms with.
The Walbiri were hunter gatherers living in a world of hunter gatherers. It is groups like this that we should be looking at for insights into our ancestral past. They suggest that, rather than a propensity for lethal violence, human males have something more like a controlled capacity for it.
Why were some hunter gatherers surprisingly peaceful?
While some hunter gatherers certainly did experience high rates of lethal violence, such as the Murngin in Australia with a violent death rate of 330 per 100,000 people, many were surprisingly peaceful. For example, the Hadza, from Tanzania, exhibited an unusually low violent death rate of 6.6 per 100,000 and no deaths from warfare. Compare that with, for example, the USA, which currently has a rate of 7 per 100,000. The Japanese Jomon cultures had a low lethal violence death rate, only 0.9 percent of deaths over 9,000 years, which equates to about 30 violent deaths per 100,000 people per year.
The 13,700-year-old Jebel Sahaba site is the earliest undisputed evidence of warfare, meaning that there is no clear archaeological evidence for warfare for the first 286,000 years of human history. It has 98 skeletons where 25 of them exhibit the telltale marks of lethal violence. This is probably not because there was no violent warfare before this but because the archeological record is patchy: only 154 skeletons in our dataset (of 13,732) predate this graveyard.
Ethnographic studies suggest that many hunter gatherer communities held ethics of non-violence and non-exploitation. As Richard Lee, an expert on hunter gatherer societies, puts it, ‘nomadic foragers rarely glorify the warrior or confer any special status. On the contrary, the peacemakers are regarded as specially valued individuals.’
Yet despite this, even with the new lower estimates for violent death suggested by our research, the data suggests that we are a comparatively highly violent species compared to other mammals and even compared to apes and primates. Why?
The defining characteristic that drives high rates of violent death in our species is not our proclivity for lethal violence but rather our capacity for it. Human beings are unusually vulnerable to violence. We have massive heads, thin skin, puny muscles, little to no protective fur; we can’t fly, swim, or burrow away, and we’re not even very good at running away. Our children are even more fragile, particularly as babies, and take ages to mature.
At the same time, our offensive abilities make us the most lethal species on the planet. Violent attacks in a hunter gatherer context are essentially undefendable. We have abilities to collectively organize, plan, and deceive far in advance of any other species. Even lions are afraid of us. Our stone-tipped tools, poisons, and projectile technology appear to have killed off almost all of the planet’s megafauna, like mastodons, giant kangaroos, and saber-tooth tigers.
Put together, these factors make human intra-species conflict extremely deadly. It is not that we have an unusual proclivity for aggressive violence. On the contrary, most other species are far more aggressive than humans. Chimpanzees, for example, are over 150 times more likely to initiate violence against each other than we are. Rather, our species is characterized by low rates of aggression and conflict but extremely high lethality rates when conflict does arise.
Hunter gatherers prefer restraint because they understand that violent aggression inevitably exposes them to retaliatory violence. In one study of Amazonian societies, 70 percent of killings were motivated by revenge, and Paul Roscoe reports that his database of over 1,000 military actions in New Guinea small-scale societies shows that 61 percent were revenge based. Our violent proclivities are largely retaliatory rather than aggressive.
Wrangham’s view that the principal driver of violence in humans is coalitions of males rationally using aggressive violence to out-compete their neighbors depends on groups being able to do this at relatively little risk to themselves. Yet our vulnerability combined with our drive for revenge means this was rarely, if ever, the case.
Our ancestral environment therefore created evolutionary pressures that equipped us with a natural aversion to violence, a taste for vengeance, and the capacity to solve conflicts through cooperation. Our fear of violence, heightened abilities for empathy and communication, squeamishness about blood and guts, and innate dislike of bullies are, in part, solutions to the problem of violence.
Hunter gatherers also tend to be characterized by cultural features that incentivize co-operation and peace between groups, such as fluid affiliations, far-ranging family ties, extended trading and sharing networks, and shared culture. They also used tools such as ritual duels to allow for controlled violence. When tensions were high, the nomadic lifestyle of hunter gatherers meant they were able to flee to stop violence spiraling out of control.
Non-violent norms are part of what makes the hunter gatherer lifestyle viable. Why then did hunter gatherers ever let their norms break down and engage in warfare at all?
The hunter gatherer prisoners’ dilemma, aka the Hobbesian Trap
Of course, hunter gatherers did sometimes engage in strategic warfare to win resources and gain reproductive advantage. In a sample of 49 modern hunter gatherer societies deemed to be good analogs for prehistoric hunter gatherers, Christophe Boehm found that examples of conflicts where a group ‘won’ were reported in only 15 percent of these societies.
But what about the other 85 percent? Actually, hunter gatherers are often surprisingly reluctant to engage in inter-group conflicts over resources or women. A study by Fry and Soderbergh found that these factors motivated just eight percent of inter-group killings among hunter gatherers. We think that a large proportion of hunter gatherer warfare is better explained by the logic of the ‘Hobbesian Trap’.
Thomas Hobbes, the seventeenth century philosopher, said that life in the ‘state of nature’ was nasty, brutish, and short, because cooperation was so difficult. Though everyone else cooperating is ideal for your group, knowing that no one will strike you gives you an opportunity to defect from such a pact and attack first when you have an advantage, a classic prisoner’s dilemma.
As Pinker argued in Better Angels, the extreme lethality of human violence makes the Hobbesian Trap a particularly difficult problem for our species. Betrayals, sneak attacks, and the resulting counterstrikes had the potential to destroy an entire group in the space of a few minutes.
The violent death rates seen in groups like the Waorani, where 56 percent died violently, are a cautionary tale about just how bad things can get in hunter gather societies when norms of non-violence break down. The Waorani recognized their own predicament and eventually many Waorani came to embrace Christianity as a solution to violence:
Other means of attempting to stop the violence were exchange of spouses, fleeing, and grimly attempting to exterminate the other group altogether. None of the methods worked – fragile truces kept being broken, and it proved impossible to flee as far or to kill as many as would be necessary in order to end the violence . . . In the case of the Waorani, peace came following the arrival of Protestant missionaries.
Yet ultimately, while an instinct for revenge could end in cycles of bloodshed, in aggregate it likely deterred more violence than it caused. Game theory’s ‘Folk Theorem’ says that repeatedly playing games like a prisoner’s dilemma can sustain stable cooperation in the long run because players can use the threat of punishment in future rounds to sustain cooperative behavior in the present; if a player defects, then they can expect to be punished in the future, which increases the incentive to cooperate.
The relative peace achieved by some hunter gatherer groups demonstrates that although the Hobbesian Trap was a challenging problem, it was not an intractable one. Hunter gatherers were capable of peacefully co-existing despite suffering much greater resource stresses than nearly all modern societies today, despite lacking our communication tools, the accumulated wisdom of civilization, effective institutions of leadership, and despite existing in closer proximity to a multitude of politically distinct neighbors than the vast majority of modern states.
Regarding more violent tribal societies, the willingness of Waorani to adopt Protestantism as a solution to violence is far from an isolated example. The acceptance of external cultural features by tribal peoples as a solution to the problem of endemic violence is a recurrent pattern in recent global history. Highly violent societies often ‘pacify’ with remarkable rapidity and without the need for overwhelming external force, suggesting that non-violent norms hold a universal appeal even in the face of cultures that are characterized as glorifying violence.
The human capacity for peacemaking may well be one of the distinguishing features of our species.
Homicide and sociopathy
While rates of warfare were highly variable in hunter gatherer societies, hunter gatherers clearly had very high homicide rates. This is a distinctive feature of violence patterns in our species. The lethality of human violence makes killing another adult relatively easy for lone killers compared to most other species. However, murder in hunter gatherer societies was typically seen as a profound violation of non-violent norms. The extent to which it was driven by sociopathic individuals is neglected in research on violence and has important implications for modern theories of sociopathy.
Here is an account of a premeditated murder by an Inuit man and his brother-in-law. The motive was to take another man’s wife. They found their victim seal hunting on the ice. Although the brothers-in-law pretended to be friendly, he guessed their intentions and kept his knife close at hand. But one of the murderers was able to attack him from behind:
A struggle developed, while Oksoangutaq stood by watching until the embattled Ikpagittoq shouted at him “you said you wanted to kill this man, what are you waiting for?” Oksoangutaq stepped up and pushed his knife into Saojori’s neck, killing him on the spot . . . one of the wives was very frightened and ran away with her child. Oksoangutaq had no trouble catching her, and made her his wife.
Our analysis found that on average about 100 in every 100,000 prehistoric hunter gatherers died violently every year. We think most of these were likely due to everyday homicide rather than warfare. In an investigation of 148 lethal events in modern hunter gatherer societies, Fry and Soderbergh found that 55 percent involved a single perpetrator and a single victim (usually both male).
The country with the highest homicide rate in the world is currently Jamaica, with an annual rate of 52 per 100,000. Most modern states do better: the UK has a rate of under two per 100,000, and Singapore’s is under one.
High homicide rates in hunter gatherer societies are, in part, a consequence of their egalitarian political organization. Hunter gatherers generally don’t recognize formal authority figures and are highly egalitarian compared to most other types of societies. They fiercely preserve an ethic of non-coercion, working collectively to suppress individuals who display domineering behavior.
Egalitarianism has a number of benefits: it facilitates the sharing economy on which the hunter gatherer economy depends and prevents exploitation by abusive leaders. However, the absence of formal authority figures also means that hunter gatherers lack effective dispute resolution mechanisms, so individuals are left to take matters into their own hands. The Hobbesian idea that centralized authority is crucial to reducing homicide seems clearly correct. Indeed, the emergence of capable states helped to drive down homicide rates across Europe after the Middle Ages.
For hunter gatherers, the Hobbesian Trap seems to have been easier to solve between groups than within groups. This is in part because of proximity – you can stay away from other groups, but you can’t keep away from the other members of your own group.
But also the problem is that the adoption of behavioral norms of non-violence at the level of the group creates the opportunity for individual defectors to exploit those norms by adopting violent strategies that others are reluctant to employ. Therefore we believe that atypically antisocial personalities likely played an outsize role in driving the high homicide rates exhibited by prehistoric hunter gatherers.
These defector strategies are much more likely to occur at the level of the individual, rather than the group, because of the difficulty of convincing a whole group to violate a norm. Hunter gatherers don’t have strong leaders, so organizing collective group action on anything is a challenge.
In addition, the benefits of group violence are likely to accrue disproportionately to particular individuals, whereas the risks are shared by everyone. This is the case for group conflict in many types of societies, but is particularly true for hunter gatherers who tend to fight over women rather than material resources and typically live in undefendable, exposed locations.
A study of the !Kung in the Kalahari desert cataloged 22 killings over a 35 year period. Thirteen of these killings were directly or indirectly related to the actions of just two individuals, Gau and Twi, in a research population that numbered between 350-450.
The !Kung, like many hunter gatherer societies, are described as being a gentle people with a non-violent ethic. Gau on the other hand, was described by one tribe member as ‘like a lion. He ate people’. Twi’s own family described him as ‘a dangerous man.’
These individuals were not typical of the !Kung and in a modern context might be characterized as sociopathic. When we think about how violent psychologically typical people are, it is important to remember that an outsize proportion of violence is committed by psychologically atypical people.
This has parallels with modern society. In Sweden, 1 percent of the population commits 63 percent of all violent crime. Comparably high-quality data does not exist for every Western country, but the tidbits we have suggest that this pattern is normal. It has also been established that sociopathy is highly heritable and has a strong genetic component. However, there is a long-standing debate as to whether it should best be understood as a mental disorder or an evolutionary adaptation. If our interpretation of the dynamics of hunter gatherer violence is correct, it lends support to the idea that sociopathy is an adaptation.
In a modern context, sociopathy can be interpreted as a high-risk, high-return behavioral strategy, with sociopaths overrepresented both in high status professions and people with large numbers of sexual partners but also in incarceration, drug abuse, accidental death and other undesirable outcomes. In a prehistoric hunter gatherer context, a similar dynamic may have been at play, with some sociopaths benefitting by acquiring multiple wives or achieving some degree of group dominance (as Gau did), while others suffered social rejection and early death (like Twi).
How hunter gatherers stopped sociopaths from spreading violence
Though they were vulnerable to sociopaths, hunter gatherer communities did have collective mechanisms to curb them.
These would go as far as execution in serious cases. For example, both Gau and Twi were killed through group effort. The killing of Twi is described in Richard Lee’s The !Kung San. A tribesman called /Xashe was the first to attack Twi and shot him in the hip with a poison arrow. Some people tried to help Twi suck out the poison, but he turned on them, stabbing a woman in the cheek and shooting her husband in the back with a poison arrow. At that point, everyone took cover and shot at Twi. In the denouement, Lee describes how Twi sat in the middle of the village and called out.
“Hey are you still afraid of me? Well I am finished, I have no more breath. Come here and kill me. Do you fear my weapons? Here I am putting them out of reach. I won’t touch them. Come kill me.” Then they all fired on him with poisoned arrows till he looked like a porcupine.
Boehm found that, in his ethnographic sample of modern hunter gatherers, 42 percent of groups were known to have executed people for bullying or intimidating the wider group.
This dynamic of struggle between a majority committed to pro-social norms and a minority seeking to exploit them for narrow, individual advantage can be observed over and over again in hunter gatherer ethnography. It clearly also occurs today and seems to be a hallmark of our species.
The idea that some people are simply bullies by nature might be difficult to accept in cultures with deep commitments to liberal values and personal freedoms, but we shouldn’t shy away from the deep implications it has for our society. If it is true, it suggests that we should heed the example set by our prehistoric ancestors and deal with them by working collectively to restrain them rather than blaming society for their existence and attempting to treat them as if they were the same as everyone else.
This has obvious implications in the area of crime and incarceration, but also in other areas like education where protecting people from bullies could be prioritized.
The most important implications are for political institutions. The wars, genocides, and democides of the twentieth century are a warning of what happens when the worst people get their hands on the instruments of power in modern states.
How agriculturalists fell prey to sociopathic leaders
The egalitarian !Kung were able, with difficulty, to restrain the bullying, domineering impulses of Gau and Twi. But what if such individuals were to gain a position of power in a more hierarchical society? We know from modern sociopathy research that sociopaths are over-represented among the powerful, likely due to characteristics such as a drive for dominance, risk-taking behavior, willingness to disregard moral and social norms for the sake of personal ambition and high tolerance for conflict.
Consider this description of chief Moawa of the Yanomami, a small-scale agricultural group, by the anthropologist Napoleon Chagnon, who knew him personally:
He was the nastiest and most unpleasant person I’ve met anywhere . . . even people in his own village despised him but were mortally afraid of him . . . he had an unusual and devastating style, one he invented . . . he would make very long arrow points . . . they were rigid, sharp as knives and pointed at both ends . . . he would lie in wait along a secluded part of a trail and wait for a passer-by. Then he would pounce on the victim from behind and thrust his arrow point down into the victim’s lungs through the throat and silently flee.
Moawa was personally responsible for at least 22 murders. No wonder the Yanomamo suffered high rates of violence with people like him in charge.
Both Better Angels and our own data suggest that early agriculturalists were significantly more violent than the hunter gatherers they supplanted across the world. In our view, it is likely that atypically violent leaders were a major factor in driving these dramatic increases in violence. Hierarchies create the opportunity for leaders to appropriate the rewards of group conflict while often minimizing risk to themselves by making others take on the burden of the actual fighting. This is a fundamental shift in the incentive patterns of inter-group violence.
From a sample of 50 small-scale societies, Keith Otterbein found that most agriculturalists had continuous warfare, compared to 20 percent of hunter gatherers, and warfare was ‘rare or absent’ among 30 percent of the hunter gatherer societies.
The massacre sites such as those at Talheim, Herxheim, and Schletz-Aspern from around 5000 BC, where the local men and children were brutally killed and thrown into death pits, and the women apparently taken into sexual slavery, attest to the brutality of early agricultural violence. We found that at least 41 percent of the violent deaths in our early agricultural sample came from such massacre sites, whereas Nataruk was the only clearly identifiable massacre site in our entire, and larger, hunter gatherer sample, accounting for around four percent of violent deaths in the sample.
Violent leaders abound in the ethnographic literature on small-scale agricultural societies and serve as a cautionary example of the capacity for the worst people to climb to the very top in hierarchical political systems. Brutal twentieth century dictators like Mao, Saddam Hussein, and Hitler are simply the modern exemplars of an ancient pattern. Coercive leaders forcing or tricking their followers into fighting for their own selfish interests has been a problem since the invention of agriculture, and still is a major cause of conflict today. Blank slate approaches that minimize the role of individual psychology in driving group conflict are wrongheaded and actively damage our ability to recognize and address the problem.
Nevertheless, the elevated rates of violence among agriculturalists can only partially be attributed to the influence of sociopathic leaders. The fact is that the invention of agriculture fundamentally changed the dynamics and incentives for violence in our species.
We hypothesize that agriculturalists were more warlike than nomadic hunter gatherers for three main reasons:
- They stored food, had more possessions, and lived at high population densities. This made it easier to monopolize resources through the use of force and harder to avoid conflict by running away. It also means that the rewards of attacking other groups of agriculturalists are larger. Moreover these denser, sedentary populations exhibit greater disparities in size and technology, creating power imbalances that incentivize violence by reducing the risks for powerful attackers and making total annihilation of opposing groups viable.
- Their hierarchical and inegalitarian social organization made it easier to organize collective violence and coordinate on violations of non-violent norms. Leaders could coerce group violence for selfish reasons. Women had lower social status and so were less able to curb the more aggressive tendencies of men. For the same reason, it was much easier for individual men to monopolize women and slaves as part of the spoils of war.
- Small-scale farmers tend to be more self-sufficient and less inter-connected with other groups than hunter gatherers, who typically exhibit more fluid group affiliations and widespread trading networks. This means that small-scale farmers are less incentivized to cooperate with other groups and also lack the family and cultural ties that would stop them from fighting if it were in their interests.
These factors made the incentives for conflict much greater and made it much harder to overcome the Hobbesian Trap, even though agriculturalists were descended from hunter gatherers who, for hundreds of thousands of years, faced strong evolutionary pressures against violence.
What does this tell us about the world today?
The widely held belief that we are very violent and brutal by nature is misleading.
Instead, our ancestral past shows us that most people tend to recognize the zero-sum nature of most conflicts and are surprisingly adept at finding solutions to Hobbesian Traps. Recognizing this can help us to better take advantage of this useful human trait, in turn making peace more likely. It is true, for example, that modern states live in a similar way, with respect to one another, as hunter gatherers did: they are held together by loose affiliations and cultural and familial ties and have the capacity to do enormous damage to one another, but this does not mean conflict is inevitable. Anarchy at the level of the group did not guarantee violence among hunter gatherers, despite them lacking our effective instruments of authority and having vastly less knowledge and much worse technology to communicate than we do.
Yet our natural aversion to violence has not reliably protected us from it. Rather, this aversion developed precisely because of the catastrophic potential of human violence. Widely accepted norms of non-violence are not adequate to protect us from the depredations of anti-social people who choose to defect from those norms. The high homicide rates that plagued our hunter gatherer ancestors illustrate the damage caused by such people in the absence of effective authorities. In hierarchical societies, ensuring that such people do not obtain power is a perennial problem.
Unfortunately, the evidence also suggests that technological progress does not guarantee that violence will fall. The dramatic increase in violence that came with the invention of agriculture attests to that. So do the multiple examples of modern tyrants using powerful technologies to enact the horrific democides and wars of the twentieth century. This offset the dramatic decline in everyday homicide, and made the twentieth century not much less violent than the hunter gatherer period.
Since the origin of our species, trends in well-being seem to have been U-shaped. The invention of agriculture caused life to get worse for most people across many dimensions. Surprisingly, it is plausible that only since the Industrial Revolution have average living standards surpassed those of our hunter gatherer ancestors. The main threat to that trend is a repeat of the catastrophes of the twentieth century. The twenty-first century is on course to be the least violent one ever. Whether it will be or not depends on whether we have the prudence and wisdom to manage destructive technologies, restrain bullying leaders, and navigate tensions between the Great Powers in the coming decades.