Book Review Essay:

Otterbein, Keith F. (2004) How War Began. College Station: Texas A&M Press. ISBN: 1-58544-330-1, xv + 292 pages.

Fry, Douglas P. (2006) The Human Potential for Peace: An anthropological challenge to assumptions about war and violence. New York: Oxford University Press. ISBN 0-19-518178-6, xvii + 365 pages.

Gat, Azar (2006) War in Human Civilization. Oxford: Oxford University Press. ISBN 0-19-926213-6, xv + 822 pages.

by J.M.G. van der Dennen (University of Groningen, the Netherlands)


The study of war in preindustrial societies and in early civilization is riddled with controversies (apart from the usual conceptual and definitional problems). The authors reviewed here (Otterbein, Fry, and Gat) are fairly representative of the main ‘schools’ on the origin and early history of war. Fry, for example, endorses the conventional view of the origin of war as a cultural invention of 10,000 years ago. Otterbein defends the position that war originated with Homo habilis, some two million years ago. And according to Gat warfare is a common phenomenon in some vaguely conceptualised ‘state of nature’. This diversity also reflects the various views on the original belligerence or non-belligerence of “human nature”. Gat glosses over all analytical distinctions, while Otterbein and Fry emphasize at least the distinction between feud and war. In this review essay I focus on, and critically discuss, some key problems: war as cultural invention or as a product of evolution (in the Darwinian sense); the supposed relationship between hunting and warfare; warfare and feuding from a cross-cultural perspective; the evidence of warfare, or its nonhuman equivalent (intergroup collective violence), in other mammalian species; and the archaeological evidence of warfare. I also present the (chrono)logically possible positions on the evolution of battle-type and raiding-type warfare. Finally, I call attention to Fry’s valiant attempt to ‘debunk’ Ember’s widely-cited “myth of the peaceful hunter-gatherers”.


Keith F. Otterbein is a professor of anthropology at the University of Buffalo, State University of New York, and a director of the Human Relations Area Files. He has written three books and numerous articles on warfare and feuding in preliterate (hunting-and-gathering and tribal) societies.

Douglas P. Fry is a docent in the Developmental Psychology Program at Åbo Akademi University in Finland and an adjunct research scientist in the Bureau of Applied Research in Anthropology at the University of Arizona. He has written extensively on aggression, conflict, and conflict resolution from various theoretical perspectives. He is coeditor, with Graham Kemp, of Keeping the Peace: Conflict Resolution and Peaceful Societies around the World (2004) and coeditor, with Kaj Björkqvist, of Cultural Variation in Conflict Resolution: Alternatives to Violence (1997).

Azar Gat is Ezer Weitzman Professor of National Security in the Department of Political Science at Tel Aviv University. He has published widely in the field of military history and strategy, including A History of Military Thought: From the Enlightenment to the Cold War (2001), and has held research and teaching positions at Freiburg, Oxford, Yale, Ohio State and Georgetown Universities.


Otterbein’s main argument is that warfare had two separate origins and developed along two different paths. The hunting of large game animals was critical to the development of the first path. Early hunters working as a group in pursuit of game sometimes engaged in attacks upon members of competing groups of hunters; they devised a mode of warfare based upon ambushes and lines. Hunting and warfare went hand-in-hand. More people were competing for the game with better weapons and hunting tactics. Once the extinction of many large animals began, the early hunters turned to small game procurement and developed a greater reliance upon gathering wild plant food. The frequency of warfare declined, and, Otterbein believes, it did so rapidly.
At the origin of the second path were foragers who did little hunting but depended largely upon gathering for subsistence, became sedentary, and then domesticated plants. But the first people to domesticate plants did not have war, and they did not have war because they had ceased to be hunters of large game. Intergroup aggression was absent among these early agriculturalists. The first states developed only in these regions, but once city-states arose, a mode of warfare based upon battles and siege operations sprang forth. The first people to develop states did not have war until they had centralized political systems. Thus, warfare cannot be the cause of pristine state formation (pp. 10-11, 13, 15).

Otterbein has formerly already (2000) distinguished between hawks and doves. Hawks are those scholars who argue that war existed in early human history; doves are those scholars who argue that war arose only when states developed (This is in reality the umptiest variant of the Hobbes-Rousseau controversy, without Otterbein mentioning it). “I am in both the hawk and dove camp. My argument for sporadic early warfare and intense warfare in the late Upper Paleolithic places me with the hawks. My argument for long periods of peace among settled gatherers and early agriculturalists places me with the doves… I believe that my synthesis takes the essence of each approach and combines the two into a satisfying theory” (p. xiii).
This joining of the two perspectives, that early hunters engaged in warfare, while early agriculturalists did not, is, Otterbein believes, a synthesis worthy of serious consideration. It resolves the dispute between the hawks and doves by bringing the two perspectives together (p. 220).
Not everybody is happy with Otterbein’s proposed synthesis: In a brief review Keeley (2006: 261) writes: “This book’s dual theses violate Occam’s Razor… Otterbein’s dual-origin hypothesis is contrary to the known facts of world prehistory”.

The lengthy discussion of hunting in How War Began suggests four possible reasons why hunting and warfare are related: Hunters have weapons that are likely to be suitable for use in warfare; hunting itself involves searching for and killing prey; if seeking prey involves the coordinated activities of hunters, a quasi-military organization has been created; and hunters, particularly hunters of large herd animals, may range over a vast region and come in contact with other peoples who also range over a part of the territory and do not wish to share it. The first three reasons stem directly from Otterbein’s earlier research on the evolution of war, where he focused on weapons, tactics, and military organizations.
Thus, Otterbein claims, based on his previous macroquantitative research, that hunter-gatherer bands that practice the hunting of large animals are more likely to engage in warfare frequently (p. 89).
Thoden van Velzen & van Wetering (1960) argued that a fraternal interest group, which is a power group of related males, resorts to aggression when there is a threat to the interests of one of its members; in societies with power groups, any act of violence will be followed by another act of violence, thereby eliciting a chain reaction. In the ethnographic record, a custom known as patrilocal marital residence, which results in wives living in their husbands’ local groups, results in related males residing near each other. This situation is the genesis of fraternal interest groups. The individual who is a member of a fraternal interest group acts with the assurance that his group of kinsmen is ready to support him and his interests through thick and thin. Thus, any individual act of violence can lead to conflict between fraternal interest groups, and much aggression within the society can be attributed to the power groups and their struggles for power. “Fraternal interest groups, weapons, and hunting form a complex – given its ancient origin it can be called the eternal triangle” (p. 62).

A summary of what was learned about the evolution of the pristine state, according to Otterbein, looks as follows:
1. At the village level there are kinship groups with leaders, one of whom is the village headmen. There is no war. There are no military organizations.
2. At the minimal chiefdom level, Stage I, the village headman becomes a chief. There is still no war.
3. At the typical chiefdom level, Stage II, major changes occur: stratification based on wealth; conflicts between the chief and other village leaders may turn violent; assassinations and raids upon domiciles take place. War between chiefdoms, however, does not occur.
4. At the maximal chiefdom or inchoate early state level, Stage III, the chief becomes a despot. Human sacrifice of rivals, lower class members, and, later, war captives is likely to occur in a public setting as a way to emphasize the power of the emergent state and its ruler. Armies led by the chief and composed of his followers and other members of the upper class constitute a formidable fighting force. Wars against neighboring maximal chiefdoms take place. This situation is the second origin of war. Once conquests begin, a typical early state arises.
5. At the typical early state level, Stage IV, the chief becomes a king. The king heads a military aristocracy. Lower class males are conscripted into the military organization. The large armies engage in battles with opposing sides facing each other. A new basic pattern of warfare develops that is based upon line battles and siege operations. These wars between culturally similar peoples, may continue for years before one kingdom is able to rush the other. The final outcome is likely to be an even larger kingdom. The typical early state grows in terms of both territorial size and population. Eventually war chariots and an integrated tactical force, consisting of infantry, cavalry, and artillery, appear. The king now embarks on campaigns to conquer non-state peoples of other cultures.
6. At the mature state level, the monarchy continues, but despotism no longer characterizes internal relationships. A well-developed bureaucracy controls the affairs of the kingdom. A judicial system with laws develops. Conquered peoples, as well as culturally different people choosing to live under the state’s protection, transform the polity into an empire. Alliances for trade and war may be formed with other states and empires. Wars between combined armies characterize the mature state level in sociopolitical evolution.
Otterbein illustrates these six stages by case studies of four pristine states, the Zapotec (Meso-America), the Chavin/Moche (South-America), Uruk/Sumer (Mesopotamia), and Hsia/Shang (China). Otterbein does not consider Nubia and Egypt to be pristine states, unlike Cioffi-Revilla (1996, 2000), who defends the so-called ‘pleogenesis’ or multiple-invention theory of the origin of war, which states that war has been ‘invented’ independently in these ‘protobellic’ areas.
Otterbein thus identifies an evolutionary sequence that goes from no war, to internal conflict, to combat between elite warriors, to battles between massed infantry – a sequence that pertains only to the development of pristine states.
Once the idea of statehood developed, the idea could diffuse within the region to agricultural villagers and herding peoples. If those villagers and herders had the potential to produce a surplus, they would likely become states – secondary states. If not, they would become tribes. This is another idiosyncratic and unorthodox Otterbeinian idea: tribes are not an intermediate sociocultural-evolutionary level between band-level societies and chiefdoms/states, as is the conventional wisdom, but tribes are, in Otterbein’s universe, essentially failed states. Tribes do not conquer each other and become chiefdoms, nor do tribes become states.
The cardinal characteristic of the early state is coercion (which manifests itself in taxation, conscription, and obedience to authority in a hierarchical command structure), which lies at the base of early state warfare.

Among early agriculturalists, Otterbein claims, war was absent – indeed, it had to be absent: “Agriculture and village life are inextricably linked – one cannot exist without the other. In their earliest development they went hand-in-hand; village life produced crops and crops produced village life. Warfare had to be absent for both to occur; ambushes, raids, and battles would have disrupted the settled way of life necessary for the origin of agriculture and the later development of the state” (p. 91). “Warfare along the Nile River before 10,000 B.C.E. prevented the process of domestication from starting in that region” (p. 94). “The absence of warfare is a prerequisite for both domestication of plants and, later, for the development of centralized political systems… warfare cannot be the impetus for statehood… The mantra that ‘war make states and states make war’ is rejected, although the second half of the statement he accepts as correct (p. 96-97). In the Near East, the settlement of Abu Hureyra, occupied from 9500 to 5000 B.C.E. is a wonderful example – nearly five thousand years of continuous occupation and no warfare (p. 222).

The basic pattern of ambushes and lines, Otterbein claims, has a logic that has not been recognized by most scholars who have studied the warfare of nonliterate peoples. Historians in particular have focused on line battles, noted the low casualty rates, and concluded that ‘primitive’ warfare is ritual. They have overlooked the importance of ambushes; in many tribal societies, and band societies as well, heavy casualties occur in ambushes. One frequently finds uncentralized political systems with the basic pattern of warfare: ambushes, often in conjunction with raids, yielding high casualties, and line battles, yielding low casualties. Line battles appear to be a testing of strength, whereas the ambush is the tactic chosen to inflict great casualties or to destroy an enemy village (p. 202).

“The basic pattern of ambushes and lines has a logic that has not been recognized by most scholars who have studied the warfare of nonliterate peoples. Historians in particular have focused on line battles, noted the low casualty rates, and concluded that primitive warfare is ritual” (p. 202).
I take it that the historians in particular that Otterbein refers to are military historians Dyer (1985) and Keegan (1993), who, together with Ehrenreich (1997) and others, are indeed co-responsible for disseminating the notion that warfare in nonliterate societies was a harmless, non-bloody, highly ritualized, affair.
I don’t know who these “most scholars” are but Corning (2003), Eibl-Eibesfeldt (1975), Falger (1994), Gat (2000), Keeley (1996), Low (1993, 2000), Meyer (1981), Thayer (2004), Wrangham (1999), and most other scholars of warfare in nonliterate societies (including myself) are fully aware that raiding, sneak attacks and ambushes in these societies were/are utterly lethal and disgustingly bloody affairs; often indiscriminate massacres with genocidal intent.

How War Began challenges several established notions, first, the notion that there was no warfare before the Neolithic period. Second, the notion that early agriculturalists, including the first residents of Jericho, engaged in warfare. Third, the notion that military conquests led to the first states. There were no conquests until there were states. States led to war; war did not lead to states (p. 220).


In The Human Potential for Peace, Fry shows how anthropology – with its expansive time frame and comparative orientation – can provide unique insights into the nature of war and the potential for peace. Challenging the traditional view that humans are by nature primarily violent and warlike, Fry argues that along with the capacity for aggression humans also possess a strong ability to prevent, limit, and resolve conflicts without violence. Raising philosophy of science issues, the author shows that cultural beliefs asserting the inevitability of violence and war can bias our interpretations, affect our views of ourselves, and may even blind us to the possibility of achieving security without war. Fry draws on data from cultural anthropology, archaeology, and sociology as well as from behavioral ecology and evolutionary biology to construct a biosocial argument that challenges a host of commonly held assumptions. In showing that conflict resolution exists across cultures and by documenting the existence of numerous peaceful societies, the book demonstrates that dealing with conflict without violence is not merely a utopian dream. The Human Potential for Peace also explores several highly publicized and interesting controversies, including Derek Freeman’s critique of Margaret Mead’s writings on Samoan warfare; Napoleon Chagnon’s claims about the Yanomamö that unokais (men who have participated in a killing) average more than three times the number of wives and more than three times the number of children than non-unokais of the same age; and ongoing evolutionary debates about whether hunter-gatherers are peaceful or warlike.

Some authors propose that even the simplest cultures, nomadic hunting-and-gathering (foraging) bands are warlike. Keeley (1996: 30-31), for example, writes, “There is nothing inherently peaceful about hunting-gathering or band society”. Wrangham & Peterson (1996: 75) assert that “no truly peaceful foraging people has ever been found or described in detail”. As a theme spanning such arguments, not only is warfare viewed as pervasive across cultures, but it also is seen as an extremely ancient practice.

In his The Human Potential for Peace, Fry proposes an idea that at first may seem improbable, namely, that the view that humans are fundamentally warlike stems much more from the cultural beliefs of the writers than from “phenomena observed in the physical world” – from data, in other words (p. 2).
For example, Wright (1942) observed that some societies in his large cross-cultural sample were nonwarring but, nonetheless, classified the whole sample within four categories called political war, economic war, social war, and defensive war. Consequently, the nonwarring societies were labeled as engaging in at least defensive war, because there simply were no alternatives like peaceful or nonwarring in the classificatory scheme. This is analogous to labeling everybody as being sick, for instance, as critically ill, chronically ill, periodically ill, or undiagnosed, with no category for healthy. Such labels subtly imply that illness is the natural state of affairs. Wright’s war classification scheme is merely one example of research that seems to reflect a belief bias in Western culture that war is natural.

Fry reasons that visualizing a peacefulness-warlikeness continuum is useful for several reasons. It suggest that dichotomizing between peaceful and belligerent cultures is an oversimplified distortion. Another point is that the peacefulness-warlikeness of a given society is not immutably fixed through time. Shifts toward violence and shifts toward peacefulness occur over years, generations, and centuries. The fact that a culture has a high level of physical violence today does not preclude a change toward peacefulness in the future. For example, Carole and Clay Robarchek describe how the Waorani of Ecuador managed to decrease their initially high rate of homicide by over 90 percent in just a few years. “The killing stopped because the Waorani themselves made a conscious decision to end it” (Robarchek & Robarchek, 1996: 72).

The Paucity of Warfare among the Australian Aborigines

In Aboriginal times in Australia, lethal violence took the form of murder, vengeance killings, and feud (more accurately called individual self-redress in most cases). Some deaths also occurred in the administration of Aboriginal law: during juridical fights, duels, and the punishment or execution of wrongdoers. However, lethal intergroup violence that could be considered warfare was truly the exception to the well-established peace system of the Australian Aborigines (Fry, 2006: 147). This observation is confirmed by a great number of sources who have intimately studied the Australians (Westermarck, 1910: vi; Wheeler, 1910: 149; Spencer & Gillen, 1927: 27-28; Davie, 1929: 52; Murdock, 1934: 45; R. Berndt, 1965: 202; Meggitt, 1965: 245-246; Hoebel, 1967: 306; Birdsell, 1971: 341; Service, 1966: 103; 1971: 18; C. Berndt, 1978: 159; Tonkinson 1978: 118, 127; 2004; Hart & Pilling, 1979: 85; N. Williams: 1987: 31, 39; Horton, 1994: 1153; Berndt & Berndt, 1996: 362; among others).
In fact, loosely applying martial vocabulary like “war” and “battle” to individual self-redress, feuds, punishment of wrongdoers, and even regulated fights, which serve as a form of conflict resolution, occurs with some regularity in the literature on Australia and elsewhere (e.g., Gat, 2000: 27). For example, Warner tallied up violent deaths among the Murngin, lumping together those that resulted from individual fights, group fights, revenge homicides, and even capital punishment. Compounding the confusion, Warner titled his chapter “Warfare” and therein stated that “there are six distinct varieties of warfare among the Murngin” (Warner, 1969: 155; italics added). Such labeling muddles the issue, for as Ronald and Catherine Berndt point out about Warner’s six types, “Not all can be termed warfare” (Berndt & Berndt, 1996: 358). In accordance with Williams’ assessment that Murngin violence is actually blood revenge, Warner reports that the majority of the killings stemmed from revenge seeking (Williams, 1987; Warner, 1969: 148). One of Warner’s six types of so-called warfare, the makarata, actually is, in his own words, “a ceremonial peacemaking fight” (Warner, 1969: 155). According to Warner’s observations over a 20-year period, no deaths resulted from makarata ceremonies (Warner, 1969: 155-156). It is very confusing to call a nonlethal peacemaking ceremony “warfare” (Fry, 2006: 148-149).
Only one type of Murngin fighting, called the gaingar, actually resembles warfare. Tactically, men from different clans face off and throw spears to kill. Seeking revenge for previous unavenged killings is a major motivation for this “spear fight to end spear fights.” Over the 20-year period investigated by Warner, two gaingar fights took place, which resulted in a combined total of 29 deaths. The Murngin gaingar, whether labeled war or feud, represents perhaps the bloodiest exception to the typical Australian Aborigine pattern characterized by a dearth of lethal intergroup encounters (p. 149).

From this body of data on Australian Aborigine societies, an overall conclusion is clear. With very occasional exceptions, disputes that might at first seem to be between communities in fact turn out to be personal grievances between individuals living in different communities. Sometimes such grievances lead to revenge against particular individuals or their close kin, thus constituting personal self-redress, which if reciprocated amounts to feuding, not war between communities. Events that could be considered warfare are extremely few and far between in the ethnographic record of Aboriginal Australia, and in some exceptional cases may have been prompted by territorial loss and other changes caused by the arrival of Europeans (Birdsell, 1971: 341; Fry, 2006: 151).

War-laden Scenarios of the Past

Ghiglieri (1999) assumes that warfare is ancient (“wars are older than humanity itself’), that warfare is natural (“Wars erupt naturally everywhere humans are present”), and that warfare has been critical in human evolution (“War vies with sex for the distinction of being the most significant process in human evolution”) (Ghiglieri, 1999: 161, 163, 162).

In this and similar scenarios of prehistoric life, war is assumed to result from selection pressures operating over a long expanse of evolutionary time. A careful analysis of these works, which Fry (2006: 164) refers to collectively as the Pervasive Intergroup Hostility Model, reveals interconnected assumptions about the human past. War is extremely ancient. Intergroup relations tended to be hostile in the past. Group membership was largely fixed – the exception being that women were captured from neighboring groups as a goal of war. The males in a group were genetically related to one another, perhaps as members of a patrilineage. Related males readily bonded and cooperated with each other in warfare. Effective male bonding and cooperation in war paid off in terms of increased reproductive success for males engaging in these behaviors. Critical resources were scarce. War was waged to acquire scarce resources, territory, and women. Leadership and warrior behaviors correlated with reproductive success and thus were evolutionarily favored.
This evolutionary scenario might prima face seem reasonable. Despite the apparent plausibility of this scenario, Fry (p. 164) proposes that the assumptions underlying the Pervasive Intergroup Hostility Model are unrealistic and simply untenable.
Do data on the simple nomadic hunter-gatherer lifestyle support the cluster of assumptions that during human evolution, hostile, tightly knit, closed groups of related males regularly made war on neighboring groups over scarce resources, including territory and women? To separate the issues for analysis, are ethnographic data on forager bands supportive of the following assumptions about the past? (1) Groups consisted of male-bonded patrilineages in common residence. (2) Groups were tight-knit and bounded. (3) Intergroup hostility and warfare were prevalent. (4) Chronic resource scarcity caused wars. (5) More specifically, wars were waged over territory and to abduct women. (6) Military virtues and leadership were valued and prevalent (p. 166).

Ø The Patrilineal-Patrilocal Assumption
Groups of related males, linked via a common ancestral male into a patrilineage and living together in what anthropologists refer to as patrilocality, are by no means universal features of nomadic hunter-gatherer bands. Reviewing the issue in 1983, Alan Barnard concludes that “new generations of scholars gave the coup de grace to the patrilocal model. All over the world, societies of small community size were shown to be neither essentially virilocal nor patrilineal in any sense” (Barnard, 1983: 196). Contradicting the assumption of the Pervasive Intergroup Hostility Model, bilateral descent is most typical, which means that kinship to mother’s and father’s relatives are on equal terms. Furthermore, rather than male relatives clustering together in patrilocal residence, a great deal of flexibility exists among nomadic hunter-gatherers regarding residence patterns (pp. 167-168).

Ø The Assumption of the Tight-Knit Bounded Group
Fry (pp. 168-169) concludes that to assume that ancestral human groups were tight-knit kin groups closed off from other such groups is extremely unrealistic in light of the evidence from simple nomadic foragers in various parts of the world. The overall pattern among nomadic foragers of flux and flexibility in group composition is extremely well documented and unambiguous.

Ø The Assumption of Pervasively Hostile Interband Relations
Undoubtedly, relations between certain foraging bands were hostile on occasion in the evolutionary past. The important question, however, is whether or not assuming pervasive, or even typical, intergroup hostility and warfare is really justified.
Observations of nomadic hunter-gatherers suggest that typical patterns of interband interaction can aptly be characterized as benign coexistence or friendly contact, with pervasive intergroup hostility and warfare being relatively rare (pp. 169-171).

Ø The Assumption of Warring over Scarce Resources

This assumption actually entails a subset of other assumptions, all of which are open to debate. First, we can question assumptions about the nature and value of material goods. Second, related to natural resources, we can raise issues about presumed shortages in ancestral environments. Third, we can question the assumption that humans would be inclined to cope with resource scarcity via war. An examination of the patterns within ethnographic material on simple hunter-gatherers calls all these assumptions into question. Finally, we can ask whether assuming conditions of scarcity to have existed in the human evolutionary past makes sense given the earth’s meager population for most of prehistory (pp. 174-175).

Ø The Assumption of Warring over Land

The assumption that territorial warfare was the chronic condition among hunter-gatherers over past millennia ignores the variability and complexity of how hunter-gatherer bands interact regarding resources and land (p. 179).

Ø The Assumption of Warring over Women

What about the proposition that women were the scarce resources over which men of prehistoric bands warred? In some simple nomadic hunter-gatherer societies, men do fight over women from time to time. However, most ethnographic accounts of such disputes are not variations on a Helen of Troy theme: Disputes over women invariably involve particular men and particular women, but rarely entire bands warring with other bands. These types of individual grudges may or may not lead to interpersonal violence, but they rarely lead to anything resembling war between entire nomadic bands. The relevant point is that in some nomadic forager societies, individual men may fight over a woman, but groups of men tend not to march off to war over women (pp. 179-180).

Of relevance to this topic, the simplest foraging societies tend to have high levels of gender egalitarianism (Endicott, 1999). To simply assume that women are the spoils of men’s battles – to “use them reproductively,” as Ghiglieri (1999: 197) puts it – hardly takes female autonomy and decision-making into account.
The ethnographically recurring pattern of hunter-gatherer gender equality calls into question the assumption that forager women are “war trophies,” typically subjected to capture by groups of warring men. Of course it would be absurd to suggest that no nomadic hunter-gatherer woman has ever been violently abducted (e.g., Honigmann, 1954: 95 on the Kaska; Osgood, 1958: 63-65 on the Ingalik). On the other hand, the ethnographic data do not support a generalization that waging war to abduct women is in any way typical or pervasive among egalitarian nomadic forager societies (Fry, 2006: 181).

Ø The Assumption of Leadership
Nomadic hunter-gatherer societies are characterized by egalitarian values, high levels of personal autonomy, and the lack of formal leaders. The data contradict assertions that members of nomadic foraging bands have martial values, reward military leadership, or emphasize warrior skills. Assumptions that in the evolutionary past, military success correlated with reproductive success or that natural selection selected for leadership abilities (e.g., Ghiglieri, 1999: 196; Low, 1993: 35, 40) are simply not substantiated by data on nomadic forager societies. Cooper’s statement about the Ona applies generally to simple nomadic hunter-gatherers: “No man recognized authoritative headship of or accepted orders from any other” (Cooper, 1946: 116). Boehm, who has read extensively in the cross-cultural literature, doesn’t beat around the bush: “Egalitarian foragers uniformly eschew strong, authoritative leadership” (Boehm, 1999: 208). Clearly, the assumption that leadership, military or otherwise, is important in an egalitarian forager context is a very poor one (Fry, 2006: 181).

Unokais do not average over three times the off-spring and two-and-a-half times the wives as do non-unokais. Fry’s calculations show that the combined effects of age and headmanship are substantial. Even the most conservative calculation (age alone) cuts the originally reported unokai advantage by 56 percent, whereas the most liberal (yet plausible) calculation combining corrections for age and headman effects totally eliminates any unokai advantage. Furthermore, using a sedentary, horticultural, tribal society structured in terms of patrilineages as a model for ancestral human society is problematic. Third, findings from one study on one society have only limited generalizability (Fry, 2006: 198).

Fry (2006: 199) holds that the proposal that warfare has been designed by natural selection is extremely dubious. The idea that war has evolved to enhance male reproductive success confuses adaptation with fortuitous effect and also muddles the social institution of warfare with interpersonal aggression.

In Fry’s view, a reasonable case can be made that some forms of aggressive behavior have evolved in humans as facultative adaptations, but that is still a far cry from the assertion that warfare is an evolutionary adaptation. Furthermore, switching back and forth between aggression and war, as if these types of behavior constitute a unified concept, further muddles the already murky waters swirling around evolutionary discussions of warfare (p. 238).


This is an ambitious book. It sets out to find the most fundamental questions relating to the ‘riddle of war’. Why do people engage in the deadly and destructive activity of fighting? Is it rooted in human nature or is it a late cultural invention? What is the relationship to major developments in world history such as the emergence of agriculture, the rise of the state, the birth of civilization, and the advance of modernity and democracy? Is war spreading itself ever wider, or is it in decline? Combining diverse disciplines – such as biology (animal behavior or ethology), evolutionary theory, evolutionary psychology, anthropology, archaeology, history, historical sociology, and political science – and ranging from the origins of our species to the current threat of unconventional terror, Gat shows that large-scale deadly fighting has always been with us, pursued for the attainment of the very same objects that underlie human desire in general. Tracing war’s development across epochs and around the globe, he generates a wealth of insights into all major aspects of humankind’s remarkable journey through the ages (from cover text and preface).

What Gat ambitiously seeks to provide is some kind of “deep structure” (analogous to Chomsky’s linguistic deep structure and universal grammar) underlying the performance of warlike enterprises in hominid/human history. This deep structure is provided by the evolved human motivational complex, which was shaped by evolution (in the Darwinian sense as adaptation by means of natural selection) first and foremost by competition for resources and reproductive success: “The interconnected competition over resources and reproduction is the root cause of conflict and fighting in humans, as in all other animal species. Other causes and expressions of fighting in nature, and the motivational and emotional mechanisms associated with them, are a derivative of, and subordinate to, these primary causes, and originally evolved this way in humans as well” (p. 87). The motivational complex includes the quest for power and glory (or more or less equivalents rank, status, honor, esteem, prestige), acquisitiveness (territory, women, resources, commodities), revenge, cannibalism, bloodlust, etc., but also fear of other groups and the quest for security. It is important to understand that there is a deep rationality underlying our innate evolution-shaped responses. Part and parcel of this evolved motivational complex is “deadly aggression”, which functions here as a shorthand for fighting, killing, feuding, warfare, etc. This “deadly aggression” is treated as a unitary propensity, even though “there is no evidence that a widespread unitary aggressive instinct exists” as the founding father of sociobiology, Edward Wilson wrote (1978: 103). There is no fundamental distinction between homicide and warfare in Gat’s universe. There is no clue for readers that Gat is even aware that ‘war’ is conceived by most scholars as a collective, intergroup, intercommunity or intercoalitional activity with at least a modicum of organization and intragroup cooperation. It is hard to tell whether Gat is really convinced that all violence (interpersonal as well as intergroup) is a manifestation of “deadly aggression” or that it is merely an excuse for not having to make analytical distinctions and clear categories.

Fighting and killing take place both within and between tribes. This is more complex than the simple ingroup co-operation/outgroup rivalry suggested by Spencer and Sumner. Our distinction between ‘blood feuds’ and ‘warfare’, ‘homicide’ and ‘war killing’ is in fact largely arbitrary, reflecting our point of view as members of more or less orderly societies. Typically, as Franz Boas noted among the eastern, Great Plains, and north-west American Indians, ‘the term “war” includes not only fights between tribes or clans but also deeds of individuals who set out to kill a member or members of another group’. The phenomenon with which we are dealing is deadly aggression, explained by the same evolutionary rationale (p. 46; italics added).

Furthermore, “as aggression is only one possible, and highly dangerous, tactic, rather than a primary need, the emotional mechanisms that regulate it are sharply antithetical, ready to turn it on and off. On the ‘on’ side, the primary motives and drives that trigger aggression are emotionally underpinned not merely by feelings such as fear and animosity; the fighting activity itself is stimulated by individual and communal thrill, enjoyment in the competitive exercise of spiritual and physical faculties, and even cruelty, bloodlust, and killing ecstasy. These are all emotional mechanisms intended to fuel and sustain aggression. Equally, however, On the other, ‘off’, side, aggression is emotionally suppressed and deterred by fear, spiritual and physical fatigue, compassion, abhorrence of violence, and revulsion of bloodshed. It seems almost redundant to point out that there are also tremendous emotional stimuli for co-operation and peaceful behaviour. These antithetical emotional arrays, each triggered to support a conflicting stimulus, to and against aggression, are the reason why throughout the ages artists, thinkers, and ordinary folk of all sorts have claimed with conviction that people rejoice in war, whereas others have held with equal self-persuasion that people regard it as an unmitigated disaster. Both sentiments have been there, more or less active, depending on the circumstances. Singing the praises of war and decrying its horrors have both been common human responses.
Returning to our original question: is violent and deadly aggression, then, innate in human nature, is it ‘in our genes’, and, if so, in what way? The answer is that it is, but only as a skill, potential, propensity, or predisposition” (Gat, 2006: 39).

I was the first (after Davie, 1929) to make a systematic inventory and comparative analysis of war motives in foraging (hunter-gatherer) and horti/agricultural societies within a neo-Darwinian evolutionary framework (Van der Dennen, 1995 - incorporating work by Mühlmann (1940), Turney-High (1949), Meyer (1981) and others – so I have no problem at all to accept Gat’s evolutionarily-shaped, interconnected nexus of human motivations (the motivational complex) underlying warfare, though I suspect many non-evolutionarily-informed readers will.

The book contains much recycled material from earlier publications, though adapted for non-professional readers. It is hardly possible to summarize a book of more than 800 pages, with a myriad excursions in all directions, and a hypertrophied section of notes. The ambition and scope of the book may be glimpsed from the Table of Contents:

Preface: The Riddle of War.
PART 1. Warfare in the First Two Million Years: Environment, Genes, and Culture.
1. Introduction: The ‘Human State of Nature’.
2. Peaceful or War-like: Did Hunter-Gatherers Fight?
3. Why Fighting? The Evolutionary Perspective.
4. Motivation: Food and Sex.
5. Motivation: The Web of Desire.
6. ‘Primitive Warfare’: How Was It Done?
7. Conclusion: Fighting in the Evolutionary State of Nature.

PART 2. Agriculture, Civilization, and War
8. Introduction: Evolving Cultural Complexity.
9. Tribal Warfare in Agraria and Pastoralia.
10. Armed Force in the Emergence of the State.
11. The Eurasian Spearhead: East, West, and the Steppe.
12: Conclusion: War, the Leviathan, and the Pleasures and Miseries of Civilization.

PART 3: Modernity: The Dual Face of Janus.
13. Introduction: The Explosion of Wealth and Power.
14. Guns and Markets: The new European States and a Global World.
15. Unbound and Bound Prometheus: Machine Age War.
16. Affluent Liberal Democracies, Ultimate Weapons, and the World.
17. Conclusions: Unravelling the Riddle of War.

This book provides some high-quality insights and observations, such as the explanation of the psychology of the security dilemma (pp. 98-99), the treatment of ethnocentrism-cum-xenophobia as an evolved, and universal, adaptation (“Ethnocentrism is an innate predisposition to divide the world sharply between the superior ethnic ‘us’ and all ‘others’” (p. 50)), and his (almost counter-intuitive) observation that “ethnicity made states, and states made ethnicity” (p. 358).

Gat acknowledges that his ambitious project is a veritable tour de force: “With war being connected to everything else and everything else being connected to war, explaining war and tracing its development in relation to human development in general almost amount to a theory and history of everything” (p. ix).
“The broad interdisciplinary perspective that guides this book is intended to create a whole that is larger than the sum of its parts, because the book is not a survey of existing knowledge, or merely a synthesis, let alone a textbook, but is designed as a fully fledged research book throughout. As much as it builds on and enormously profits from the wealth of scholarly literature in the various disciplines, the book takes issue with many extant studies and theses on almost every point with which it deals” (p. x).
The shadow side of this ambitious approach soon becomes apparent: pretentious megalomania and irritating arrogance.
The history of human warfare is reduced to a debating club with Gat himself as the omniscient revealer of the ‘real’ ulterior truth – although he sometimes acknowledges that other authors came tantalizingly close to the solution of the problem. “Contrary to widespread assumptions…”, “Contrary to a widely held view…”, “Contrary to a prevailing view”, “Contrary to fashionable theories…”, “a much debated topic…”, “extensive scholarly debate” and similar polemics are strewn throughout the book with a generous hand.

Typical statements, reiterating vague references to ‘nature’, and “switching back and forth between aggression and war, as if these types of behavior constitute a unified concept, further muddl[ling] the already murky waters swirling around evolutionary discussions of warfare” in the words of Fry (2006: 238), are the following:

● “Leading authorities have estimated that the rate of intraspecific killing among humans is similar and in some cases greatly inferior to that of other animal species” (p. 10).

● “To repeat the point, deadly aggression is a major, evolution-shaped, innate potential that, given the right conditions, has always been easily triggered” (p. 41).

● “All this suggests that average human violent mortality rates among adults in the state of nature may have been in the order of 15 per cent (25 per cent of the men)” (p. 131).
● “As with other animal species, humans regularly fought among themselves in the state of nature. Thus, it was not the advent of agriculture or civilization that inaugurated warfare” (p. 134).
● “Fundamentally, the solution of the ‘enigma of war’ is that no such enigma exists. Violent competition, alias conflict – including intraspecific conflict – is the rule throughout nature” (p. 663).
● “Group fighting exists among many social animals – there is nothing uniquely human about it” (p. 664).
● “Thus, as this book claims, fundamentally wars have been fought for the attainment of the same objects of human desire that underlie the human motivational system in general – only by violent means, through the use of force” (Gat, 2006: 669).

Gat utilizes some simple tricks and rhetorical devices (in this context the term ruses de guerre seems appropriate) to get his message across. These are (1) selective quoting and ignoring the counter-evidence; (2) presenting the extremes as the normal situation; and (3) the pars-pro-toto technique. A good example of ignoring all sources that contradict his conviction is the alleged warlikeness of hunter-gatherers. How is it possible that Gat mentions specifically the Australian Aborigines (and Tasmanians) as paragons of belligerent hunter-gatherers, while virtually all other sources contradict this? (vide supra) This is a perfect example of selective quoting and pars-pro-toto technique combined.
An example of presenting the extremes as the normal situation is provided by the high casualty figures of warfare in ‘primitive’ societies (following Keeley) – in the region of 25 %, according to Gat (pp. 131, 663-664), which corresponds, again according to Gat, to normal rates of intraspecific killing among animals in nature, but which are, in fact, the extremes of the total sample and ignore the bulk of the evidence. In hundreds of hunter-gatherer and simple horticulturalists these figures are much lower. Quincy Wright is praised by Gat but ignored for his data on hunter-gatherers.
The figure of 25 % lethality from all sources of violence is first presented by Livingstone (1968: 8-11) in his investigation of the effects of warfare on the biology of the human species. It was subsequently favorably quoted by Symons (1979: 145) and uncritically parroted ever since (especially by popular evolutionary psychology writers such as Buss and Pinker). The figure was already extreme to begin with, based as it was on reports from war-infested areas such as Amazonia and Highland New Guinea.

Also ignored is the contemporary theorizing on, and macroquantitative evidence on geographic contiguity, international system polarity, power distribution and transition, balance of power, alliances, deterrence, trade interdependence, etc. On the other hand, the “democratic peace” thesis is treated ad nauseam. The post-World War II transformation of international wars into transnational ‘uncivil’ wars and intractable low-level conflicts is equally neglected. Finally, Gat does not make a difference between offensive and defensive warfare.

War in Human Civilization is marred by many foibles, not the least of which is the casual way war is equated with aggression, and the easy switching between the concepts of (deadly) aggression, fighting, and warfare, and a general lack of a clear distinction between interindividual and intergroup violence (It is like asserting that it is largely arbitrary to distinguish oceans, seas, rivers, lakes, and ponds because they are all manifestations of water). What, for instance, does Gat mean, when he asserts that deadly violence is ubiquitous in nature (“Among social animals, as with small-scale human societies, group fighting and killing regularly take place”)?. If he means that interindividual violence (such as infanticide, siblicide, fratricide, cannibalism, rape, and lethal male fighting over mating opportunities) is commonplace in animals, he is, at least partly, right. To give only a few examples: In two Serengeti lion prides studied extensively by Schaller (1972), the cub mortality rate was at least 67 %. Schaller lists violence by adult lions as one of the primary causes of cub death along with abandonment, predation, and starvation. Also Bertram (1975) reports a mortality of 80 % among lion cubs in the Serengeti, partly due to cub killing by adult males after having taken over the pride. According to the reliable investigation by Wilkinson & Shank (1976), an estimated 5 to 10 percent of musk ox (Ovibos moschatus) bulls on north-central Banks Island (Canada) were killed during the 1973 rut. These figures are fairly representative.

If Gat means, however, that lethal collective (i.e., intergroup, intercommunity, intercoalitional) violence is commonplace in nature, he is plainly wrong. Lethal raiding-type warfare is confined to humans and chimpanzees, while the non-human equivalent of battle-type warfare has been documented in a number of mainly primate and social carnivore species, but this violence is hardly lethal, and it is principally the females who do the fighting (vide infra). It is quite possible that the non-lethality of this type of animal ‘warfare’ is ‘caused’ by the fact that the main participants are females. The non-human equivalent of warfare is conspicuously absent in the majority of mammalian species (Van der Dennen, 1995).
Gat with his “state of nature” misses the point entirely. The point is not whether animals are capable of killing conspecifics (they are), but why some animal species (or subspecies) are capable to cooperate in coalitions in order to compete violently with other coalitions or groups as a collective entity, and approximate the nonhuman equivalent of warfare (as lethal intergroup conflict). And why only one (sub)species evolved a male lethal raiding-type, and why all the other species evolved a female-dominated battle-type of warfare. Questions which I addressed in my Origin of War, and which Gat seems totally unaware of.
Gat glosses over all analytical distinctions, while Otterbein and Fry emphasize at least the distinctions between feud and war.

Finally, a danger of the Grand Perspective taken by Gat is that the role of contingencies and improbable events in world history is downplayed or even neglected. The Grand Perspective favors a view of history as the inevitable, organic unfolding of some intrinsically designed drama. To give just one example: What triggered the British industrial revolution, the British industrial supremacy for nearly 50 years, and the greatest empire the world has ever seen, was the conquest of Bengal and the subjection and economic serfdom of the Oriental world, which enabled enormous treasures and fortunes to be brought home to England to finance the rising industrial age. This causality was clearly captured by Adams (1921: 305, 317): “It is not too much to say that the destiny of Europe hinged upon the conquest of Bengal… Possibly since the world began, no investment has yielded the profit reaped from the Indian plunder”. This conquest started with Clive’s famous victory in the Battle of Plassey on June 23, 1757, a highly improbable event. Fuller (1970: II, 16) writes in his Decisive Battles: “the astonishing improbability of a victory gained by an army of 3,000 (less than one-third of them European) with ten guns over an army of 50,000 with fifty-three guns”.



The study of ‘primitive’ war is riddled with controversies. There is no consensus even about the definition of war. There is no consensus about whether feuding should be included or excluded. There is no consensus about whether raiding (as opposed to pitched battle) should be included or excluded (some students even argue that raiding is not ‘real’ warfare). A narrow conception of biology as “genes and hormones” precludes evolutionary thinking about war, or the hominid/human propensities underlying it: Keeley (1996), for example, seems to be blissfully ignorant of ultimate questions, considering only proximate factors and then finds that biology is ‘irrelevant’. A narrow conception of ‘culture’ (as opposed to ‘nature’) precludes integration of disciplines: anything cultural cannot be natural and vice versa. This seems to be the position of  many cultural anthropologists such as Ferguson (1990). In this vision evolutionary explanations are mainly absurd. There are different views on the origin of war, and on what motives or causes are considered ‘valid’ for its explanation. There is no agreement on whether “ritual warfare” is a real phenomenon or not. Finally, students are divided of what constitutes (historical) evidence: in the narrow interpretation warfare is only about 10,000 years old or even less (Ferguson, 1984, 1990; Keeley, 1996; Cioffi-Revilla, 1996, 2000; Kelly, 2000); in the broad interpretation warfare may be 5 million years old or possibly even older (van der Dennen, 1995; Wrangham, 1999).
It is difficult to assess Otterbein’s position in this minefield. Take ritual war; in one place (pp. 34-38), Otterbein seems to demolish the concept of ritual war, only to reintroduce it elsewhere (pp. 83 and 202) as signifying a “test of strength”. Take the origin of war; at one place (p. 42) he seems to endorse Wrangham’s synapomorphy or shared derived trait in the common ancestor of chimpanzees and hominids (5 to 8 million years ago) – “Localized groups of related males are fraternal interest groups, and fraternal interest groups were the first military organizations. If this equation is correct, the roots of war do not lie 100,000 years in the past, but five million years ago” (p. 42) – and at another place (p. 219) he claims that war originated with Homo habilis (some 2 million years ago).

Otterbein, Fry, and Gat totally neglect the primate intergroup violence data I gathered (Van der Dennen, 1995: 143-214; see also Cheney, 1987) to establish beyond reasonable doubt that some 50 species of terrestrial (ground-dwelling), group-territorial primates and some other mammals, especially social carnivores, are perfectly capable of the kind of warfare (or its non-human equivalent) which Otterbein designates as ‘line’ (i.e., battle- or combat-type warfare). This means that the non-human equivalent of battle-type warfare may be a primate adaptation, or may even have evolved in at least a number of mammals generally, many million years ago (see diagram) – ignoring the battles of epic proportions in social Hymenoptera (ants and termites) because of their totally different evolutionary trajectory. Until now, only 2 (possibly 3) species have been documented to practice raiding-type warfare: humans (Homo sapiens sapiens), chimpanzees (Pan troglodytes) (Goodall, 1986; Goodall et al., 1979; van der Dennen, 1995; Wrangham, 1999; Wilson & Wrangham, 2003), and (possibly) spider monkeys (Ateles geoffroyi yucatanensis) (Aureli et al., 2006). The latter’s raiding behavior has only recently been documented and is as yet non-lethal. Raiding-type warfare is practiced only, or virtually exclusively, by the males of the species.
Battle-type warfare (or its non-human equivalent), on the other hand, occurs in many primate species and some other group-territorial mammals, such as social carnivores. These battles result mainly from chance encounters by primate groups at the borders of their territories (or home ranges). Turney-High (1949) has illuminated the ‘biomechanics’ of the line which develops more or less automatically when two groups meet in an agonistic encounter and every individual organism strives to have its vulnerable flanks protected by its neighbors. In social carnivores and “female bonded” (or female philopatric) primate species, female participation in these – more noisy than bloody – battles commonly exceeds male participation (This observation has gone unnoticed; van der Dennen, 1995, is the only one who tried to explain this profound sex difference in raiding versus battle-type warfare participation). Unfortunately, my book was almost immediately eclipsed by Keeley’s (1996) opus magnum.

Otterbein, as well as Gat, also totally neglects my research on ‘peaceful’ (or rather ‘relatively unwarlike’) peoples (I devoted more than 100 pages to this research). Otterbein is rather inconsistent, if not contradictory, in his counting of peaceful societies. On p. 218 he states “Many nonliterate societies are violent and many are not”, even though on p. 81 he states that in his cross-cultural study of warfare in a randomly chosen sample of 50 societies, he found only four such societies: the Toda, Tikopia, Copper Eskimo, and Dorobo.

Three important questions are differentially answered by these three authors: (1) How old is war?; (2) Do peaceful societies actually exist?; and (3) Were/are specifically hunter-gatherers warlike?

Discussion: Hunting and Warfare?

In my work The Origin of War (1995), I already noticed Otterbein’s outlier (exceptional) position regarding hunting and warfare in hunter-gatherer societies. All other scholars have reasoned, backed up by empirical evidence, that hunter-gatherers are the least warlike of all socio-political and subsistence technology categories. It is probably not a coincidence that the only quantitative researchers Gat (p. 16) refers to as evidence that hunter-gatherers are warlike are the Embers and Otterbein. It is an example of his ignoring-of-counterevidence tactic. Just as his discussion of the Australians and Tasmanians uses the pars-pro-toto technique as well as the ignoring tactic. Tasmanians are a wrong example. Contemporary sources all agree that the Tasmanian societies were dislocated and ‘corrupted’ by white intrusion (e.g., Van der Bij, 1929).

Ecological-evolutionary theory (EET), originally developed by Lenski & Lenski (1978), and Nolan (2003) maintains that subsistence technology is the most important single factor affecting the organization of and interaction among human societies. The major types of preindustrial societies it identifies based on their dominant mode of subsistence are, in order of increasing technological power: hunting and gathering, horticultural (gardening), and agrarian (farming). Hunter-gatherers are expected to have a relatively low rate of warfare – not because they are especially nonviolent or peaceful, as numerous accounts have shown to be wrong (e.g., Sumner & Keller, 1927; Davie, 1929; Ember, 1978; Knauft, 1987; Keeley, 1996), but because their intermittent and limited food surpluses and their nomadic lifestyle cannot sustain frequent or prolonged warfare: Men can either hunt or fight; they cannot do both. Feuding or warring families or groups, therefore, generally find it more advantageous to separate from one another than to engage in continuous or frequent war. As Keeley (1996) and others point out, however, when they do fight, casualty rates can be quite high, and “primitive” war can be quite cruel by modern standards.
Horticulturalists are expected to have higher rates of warfare than foragers, especially if they have developed the technology to make metal tools and weapons. The incidence of warfare is expected to remain high among agriculturalists because conquest of territory and the peasants who cultivate it is the primary mechanism by which elites can increase their power and wealth. Moreover, their more productive food-producing technology can support much larger armies for much longer periods of time, and their more developed communication and transportation technologies would allow more wide-ranging campaigns and permit a geometric increase in the geographical expanse and the population size of the empires they could build. Warfare would likely follow regular cycles of increase and decline in such systems, during phases of empire-building, maintenance, and collapse. Thus, overall, their frequency of warfare is expected to be very high, especially in comparison with hunters and gatherers and simple horticulturalists (Nolan, 2003: 20-22).

The synchronic quantitative evidence does not support Otterbein’s contention that hunting and warfare went hand in hand. For example, Leavitt (1977) found war absent or rare in 73% of hunting and gathering societies (n=22), 41% of simple horticultural (n=22), and 17% of advanced horticultural societies (n=29).
Using frequency-of-warfare data reported by Leavitt (1977), Lenski & Lenski (1978:164) found a clear pattern of increasing warfare associated with reliance on horticulture and the development of metallurgy. Nolan (2003), using Ember & Ember’s warfare data, found warfare rare or absent in 39% of hunting and gathering societies (n = 23), 30% in simple horticultural (n = 27), 14% in advanced horticultural (n = 35), and 17% in agrarian societies (n = 30).

Hobhouse, Wheeler & Ginsberg (1915; cf. Hobhouse, 1956) conducted the first more or less sophisticated statistical research on a large sample of ‘primitive’ societies, and concluded that, although war was not the normal condition of ‘primitive’ societies, the opposite view that “in a world of primitives all would be peace” is equally unwarranted. Although belligerence increased with social organization in general, that does not mean that most primitive cultures lived in a paradisiac condition of perpetual peace and blissful harmony.
In 1929, a Dutchman, Van der Bij, wrote a dissertation on the origin and initial development of war. On the basis of his findings (quite in accordance with the results of Hobhouse et al.) that the more ‘simple’ the people the more peaceful it tended to be, Van der Bij concluded that in the initial phase of human evolution war did not play any significant role, and most probably was lacking altogether. Only in a more advanced phase or stage of human evolution did war emerge. Because it was written in Dutch, this study has been completely overlooked by the research community.
Wright ([1942] 1965: 66) distinguished four levels of ‘primitive’ sociopolitical organization: primary (clan), secondary (village), tertiary (tribe), and quaternary (tribal federation), which eventually gave place to the city-state and nation-state. “In general”, Wright stated, “the first are the least and the latter the most warlike”.
Using essentially the same database as Hobhouse et al., Wright ([1942] 1965: 66) also found that in terms of cultural level, “It seems clear that the collectors, lower hunters, and lower agriculturists are the least warlike, the higher hunters and higher agriculturists are more warlike, while the highest agriculturalists and the pastorals are the most warlike of all”. Thus, the more ‘primitive’ the people, the less warlike it tends to be (p. 68).
Another early cross-cultural, quantitative study of war was conducted by Simmons in 1937. However, this work, too, has been completely overlooked by the research literature, and was only recently rediscovered by Rudmin (1990). Simmons coded 71 societies for 109 variables, including “prevalence of warfare”. Rudmin cluster-analyzed the variables significantly correlated with warfare in Simmons’ sample, and found three distinct clusters. The second cluster found by Rudmin might be labelled “agricultural social ecology”. In accordance with Hobhouse et al. and Wright, Simmons concluded that agriculturalists, as opposed to hunter-gatherers, were warlike. It would seem, he reasoned, that agriculture requires the permanent, exclusive use of land. Therefore acquisition and defense of land becomes an essential aspect of the agricultural social ecology. Agricultural societies also produce the surpluses that release some members of society from productive tasks to perform militaristic tasks.

In a trivariate reanalysis of Wright’s data, Broch & Galtung (1966) were able to ascertain that as societies expand and get a fixed territorial base, they become more dangerous to each other. The percentage of cultures engaging in economic and political warfare increased in an almost monotonic fashion with increasing levels of civilization.
Suspecting some common factor underlying much of the correlation, Broch & Galtung devised an “index of primitivity”, based on culture and socio-political organization. They carefully ruled out the possibility of a spurious correlation, and concluded that “within the framework provided by these variables and the range provided by those societies, belligerence is a concomitant of increasing civilization” (1966: 37; italics in original). These data, like Wright’s, are synchronic rather than diachronic, yet they strongly suggest that there is a process involved, in the sense that increasing civilization would lead to increasing belligerence.
Subsequently, Ember & Ember (1997: 5) reached the cautious conclusion that “foragers in the ethnographic record had warfare fairly often on average, but they do seem to have had less than nonforagers”.

In a study of 84 ‘primitive’ tribes, using a different data base, Eckhardt (1975, 1982) concluded that peace is ‘natural’ and war is ‘civilized’: the more developed and settled agricultural tribes engaged in more acts of killing, mutilating, and torturing the enemy than did the more primitive nomadic tribes.

Wrangham, Wilson & Muller (2006) present a table with annual mortality rates from intergroup violence in human subsistence societies, comparing the deaths/100,000/year from lethal violence in a number of hunter-gatherers and farmers. The hunter-gatherers comprise the Agta, Andamanese, Canadian Eskimo, Dobe !Kung, Ginjingali, Modoc, Murngin, Piegan (Blackfoot), Semai, Tiwi, Yahgan, and Yurok. The farmers comprise the Auyana, Bokondini Dani, Buin, Chippewa, Dugum Dani, Fijians, Gebusi, Grand Valley Dani, Hewa, Kalinga, Kato, Kunimaipa, Mae Enga, Manga, Mohave, Mtetwa (Zulu), Tauade, Tauna Awa, Telefolmin, and Yanomamö. The median of the hunter-gatherers (n = 12) is 164 deaths/100,000/year, while the median of the farmers (n = 20) is 595 deaths/100,000/year.

A Comparison of Simple and Complex Hunter-Gatherers

Murdock (1967, 1981) has published coded information on hundreds of societies. This Standard Cross-Cultural Summary contains 35 hunter-gatherer societies. By examining other Murdock codes, these hunter-gatherer societies can be divided into three subgroups. Simple hunter-gatherers are those societies rated as nomadic or semi-nomadic, lacking domestic animals including horses, and lacking class distinctions. Complex hunter-gatherers are those rated as not being nomadic or as having social class distinctions. Equestrian hunter-gatherers, those societies relying on horses for hunting, are a third type of society of very recent origin. These ratings yield 21 simple hunter-gatherer societies, nine complex hunter-gatherer societies, and five equestrian hunter-gatherer societies. It is possible also to use ethnographic information for each society to classify it as warring or non-warring.
The essential finding is that all the complex hunter-gatherers and all the equestrian hunter-gatherers make war; whereas a majority of the simple hunter-gatherers do not. It appears that both social complexity and adoption of the horse greatly increase the chance of warfare (Fry, 2006: 105). See Table 1.

Discussion: Warfare and Feuding from a Cross-Cultural Perspective

According to Textor’s (1967) A Cross-Cultural Summary, in a sample of 45 societies, “warfare is prevalent” in 34 and “not prevalent” in the remaining nine. Drawing on data reported in a separate study of 32 societies, Textor lists eight societies where “warfare is common or chronic” and 24 where “warfare is rare or infrequent. Whereas these findings suggest that some societies are much less warlike than others, they do not clearly address the question as to whether war is always present or not. Do all cultures have war?

In a sample of 50 cultures, Otterbein (1968) found that 36 percent infrequently or never engaged in internal war. Regarding external war, Otterbein rated each culture in two ways, for the frequency with which they attacked communities from other cultures and for the frequency with which they were attacked by communities of other cultures; 48 percent of the sample were attacked infrequently or never and 40 percent attacked other cultures infrequently or never.
If we examine the three warfare subcategories in relation to each other, we find that 10 percent (5 of 50) of the societies infrequently or never engage in any internal or external war (either attacking or being attacked). Next, if we ask how many of these societies fit the ‘never’ part of the rating, the answer is that war is absent from 4 societies of these 50 – in other words, from eight percent of the sample (Fry, 2006: 86-87).
Clearly, the vast majority of Otterbein’s sample engaged in either internal or external warfare, but a few of the societies did not engage in any type of war. However, before reaching a conclusion that about eight percent of societies lack war, a methodological complication should be mentioned. The manner in which this sample was assembled – with the goal of studying war – would seem to favor the inclusion of warring cultures. This is the case because Otterbein rejected many potential societies before arriving at the final sample of 50. One of the criteria among several that he used for dropping societies from the sample was if data on war were lacking. “In all, 61 societies were dropped from the sample... and 24 because data on military organization, tactics, and the causes of war were not in the sources” (1970: 11).
One plausible reason that information on war would be lacking from ethnographic sources is that war actually is absent or rare in the culture and therefore there are no details to portray.
In his extensive overview, Indians of North America, Driver (1969: 310) concludes that whereas feuding sometimes existed, “most of the peoples of the Arctic, Great Basin, Northeast Mexico, and probably Baja California lacked true warfare before European contact”. Moreover, Driver summarizes that for the North American Sub-Arctic region, Northwest Coast, Plateau Region of the Northwest, California, and the Southwest, whereas some societies in these immense regions did make war, “at the same time, all these areas included some peoples with little in the way of violence, raids, or feuds, and no hostilities pretentious enough to be labeled war” (1969: 312).

Jorgensen and his collaborators surveyed 172 societies of western North America and conclude:

One of the most obvious and interesting aspects of the cultures of western North America’s Indians at the time of contact with Europeans was that so few societies actually engaged in persistent offensive warfare, or even raiding, yet the prospects of armed altercations deeply influenced the internal organizations and external relations of these aboriginal societies (Jorgensen, 1980: 241).

In general, the southern Athapascans were not particularly warlike (Elsasser, 1978). Although warfare on a large scale was rare, murder or trespassing frequently led to brief conflicts among the Cahto (Kato) and Sinkyone, Yuki, Huchnom, Wailaki, or Northern Pomo, with loyalties often shifting from war to war. Mortalities were usually low (Kroeber, 1928; Myers, 1978). Yokuts and Monache societies apparently were generally peaceable ones with their peoples showing little enthusiasm for armed conflict (McCorkle, 1978).

In contrast to Otterbein and many other anthropologists, Ember & Ember (1992), defined ‘war’ so broadly as to encompass feuding and revenge killings if undertaken by more than one person. Counting feuding and revenge killings directed at particular individuals as “warfare events” increases the number of societies that are reported to practice “war,” by this expansive definition, and similarly this tallying procedure inflates estimates as to how often this so-called war is reported to occur within particular societies. For example, the “war” that the Embers report as occurring “every year” for the Andamanese and slightly more often than “once in every 3 to 10 years” for the Yahgan is mostly based on instances of blood revenge and feuding between disgruntled individuals, perhaps aided by their kin (Radcliffe-Brown, 1922: 84; Gusinde, 1937: 885, 893; Cooper, 1946: 95). In other words, what the Embers call warfare frequency for the Andaman Islanders and Yahgan more precisely represents a frequency estimate for brawls, homicides, and revenge killings combined.

This assessment suggests that the Embers’ “war” frequency ratings for both these societies, and perhaps some others in their sample, are based on some combination of revenge homicide, feuding, and nonlethal brawls, but not actually on warfare as usually conceived.
This discussion illustrates the importance of clearly specifying the manner in which war is being defined. The overall conclusion about the absence and rarity of “war” based on the Ember and Ember study can be stated as follows. “Even when ‘war’ is defined so broadly as to include individual instances of blood revenge and feuding, it is still “absent or rare “ in 9 percent to 28 percent of the societies in a large cross-cultural representative sample of societies, depending on whether one includes only “unpacified” societies or all the societies in the sample” (Fry, 2006: 89).

From the Hobhouse, Wheeler & Ginsberg sample, Wright (1942) was able to rate the vast majority of the societies, 590 in all, regarding warfare. Thirty societies (5 percent of the total) were found to have no war – that is, the literature revealed no evidence of warfare, no military organization, and no special weapons. Another 346 societies (59 percent of the sample) were rated “to be unwarlike or to engage only in mild warfare,” provided that “no indication was found of fighting for definite economic or political purposes in the more specialized literature.” Combining the no war and unwarlike categories shows that nearly two-thirds of the total sample (64 percent) were non-warring or mild-warring. The rest of the sample were determined by Wright to engage in war for economic or political purposes (29 percent and 7 percent of the total, respectively).
It is also important that a substantial number of the so-called unwarlike groups engaged in feuding, and nothing more. If we conceptually untangle feuding from warring – as Fry has argued we should – then the societies that Wright coded as unwarlike based solely on descriptions of feuding should more appropriately be thought of as non-warring. But putting this issue aside for the time being, Wright’s findings highlight a very important point: War is either lacking or mild in the majority of cultures! The cross-cultural picture is not nearly as Hobbesian as is often assumed (Fry, 2006: 97).

Ember’s Cross-Cultural Study

In 1978, Carol Ember wrote, “I wish to address myself to one other view of hunter-gatherers that I have reason to believe is erroneous – namely, the view that hunter-gatherers are relatively peaceful.” Ember reported that only ten percent of her “sample of hunter-gatherers... were rated as having no or rare warfare” (Ember, 1978: 443).
Many writers continue to cite this study, and therefore it is important to address this apparent contradiction. First, Ember defines war so as to include feuding and even revenge killings directed against a single individual. Under this definition, personal grudges that result in a killing can be counted as acts of ‘war’.
A second serious issue is that almost half of the societies in Ember’s sample are not simple nomadic hunter-gatherers at all! Seven equestrian cultures are included: the Ute, Kutenai, Coeur D’Alene, Gros Ventre, Comanche, Crow, and Tehuelche. These societies represent 23 percent of the sample of 31. The use of horses to hunt game, such as bison on the North American plains, was a very recent cultural development, occurring only after the Spanish introduced the horse into the Americas. Prior to becoming horse cultures, some societies practiced horticulture and others hunted and gathered. The arrival of Europeans brought a multitude of changes to these societies, such as a shift in their economies to mounted hunting. Increased militarism was another dramatic change.
Regarding, for instance, one of the equestrian cultures in Ember’s sample, the Comanche, Hoebel explains that a great transformation occurred regarding warring and raiding. Prior to adopting the horse, the Comanche, as a subgroup of Shoshoneans, had nomadically foraged in small bands. “War was a thing to be avoided, for the Basin Shoshoneans had no military organization and were wholly lacking in fighting prowess,” writes Hoebel. After adopting the horse, they became the “Spartans of the Prairies,” and “gave trouble to all their enemies and to themselves” (Hoebel, 1967: 129). Such societies certainly do not constitute a very good model of humanity’s past (Fry, 2006: 173-174).
Furthermore, a substantial number of the societies in Ember’s sample are neither egalitarian nor nomadic but instead are hierarchical and partially or totally sedentary. The latter features characterize complex hunter-gatherers. As we have seen, the overall pattern is that complex hunter-gatherers tend to be warlike (and, archaeologically speaking, very recent), in contrast to simple hunter-gatherers, who tend to be unwarlike (and represent the oldest form of human social organization). Three sedentary societies (Aleut, Yurok, and Bellacoola) and five semi-sedentary societies (Squamish, Maidu, Nootka, Eastern Pomo, and Pekangekum) are included in the sample, representing another 26 percent of the total. Furthermore, seven of the eight sedentary and semi-sedentary societies have some degree of hierarchical class stratification.
Together, 48 percent of the sample either are partly or totally sedentary or are equestrian hunters. Therefore, the findings of Ember’s study cannot legitimately be used to draw inferences about simple hunter-gatherer bands or the nomadic foraging past. Consequently, this study cannot be taken as evidence that warfare is common among simple nomadic hunter-gatherers, the type of society that we are focusing on to provide insights about the nomadic hunting-and-gathering past (Fry, 2006: 174).

The Archaeological Evidence of Warfare

We have seen that, in actuality, many non-warring cultures exist. Similarly, the belief that “there always has been war” does not correspond with the archaeological facts of the matter. The earliest clear evidence for warfare dates from about 10,000 years ago (Ferguson, 1984, 1990), and war becomes more common with the rise of the state several millennia later. After reviewing the archaeological record, Sponsel reached the conclusion that “During the hunter-gatherer stage of cultural evolution, which dominated 99 percent of human existence on the planet... lack of archaeological evidence for warfare suggests that it was rare or absent for most of human prehistory (Sponsel, 1996: 104; italics in original). Keeley acknowledges the very recent time frame for warfare. Sponsel’s conclusion about the rarity or absence of warfare for most of prehistory, while perhaps contradicting popular beliefs as to the great antiquity of war, nonetheless is in accordance with the archaeological facts (Fry, 2006: 141).

Regarding the antiquity of warfare, Fry ignores two strands of indirect evidence: (1) the universality of ethnocentrism-cum-xenophobia. Ethnocentrism-cum-xenophobia would not have evolved if groups had not been potential threats to each other during hominid/human evolution. And (2) the “phylogenetic continuity” argument as I called it (van der Dennen, 1995, 2002a,b): it is highly improbable that the early hominids/humans had not at least a modicum of intergroup hostility, given the fact that their evolutionarily nearest nephews (the great apes: chimpanzees, bonobos, gorillas; as well as the Old World monkeys) do have intergroup hostility in their behavioral repertoire (and in the case of the chimpanzee blatant xenophobia as well).


Adams, B. (1921) The Law of Civilization and Decay. 3rd ed. New York: Macmillan.

Aureli, F.; C.M. Schaffner; J. Verpooten; K. Slater & G. Ramos-Fernandez (2006) Raiding parties of male spider monkeys: Insights into human warfare? American Journal of Physical Anthropology, 131, 4, pp. 486-497.

Barnard, A. (1983) Contemporary hunter-gatherers: Current theoretical issues in ecology and social organization. Annual Review of Anthropology, 12, pp. 193-214.

Berndt, C.H. (1978) In Aboriginal Australia. In: A. Montagu (Ed.) Learning Non-Aggression: The Experience of Non-Literate Societies. Oxford: Oxford University Press, pp. 144-160.

Berndt, R.M. (1965) Law and order in Aboriginal Australia. In: R.M. Berndt & C.H. Berndt (Eds.) Aboriginal Man in Australia. London: Angus & Robertson, pp. 167-203.

Berndt, R.M (1972) The Walmadjeri and Gugadja. In: M.G. Bicchieri (Ed.) Hunters and Gatherers Today. Prospect Heights, IL: Waveland, pp. 177-216.

Berndt, R.M. & C.H. Berndt (1996) The World of the First Australians. Canberra: Aboriginal Studies Press.

Bertram, B.C.R. (1975) The social system of lions. Scientific American, 232, 5, pp. 54-65.

Birdsell, J.B. (1971) Australia: Ecology, spacing mechanisms and adaptive behaviour in aboriginal land tenure. In: R. Crocombe (Ed.) Land Tenure in the Pacific. New York: Oxford University Press, 334-361.

Boehm, C. (1987) Blood Revenge: The Enactment and Management of Conflict in Montenegro and Other Tribal Societies. Philadelphia: University of Pennsylvania Press.

Boehm, C. (1999) Hierarchy in the Forest: The Evolution of Egalitarian Behavior. Cambridge, MA: Harvard University Press.

Broch, T. & J. Galtung (1966) Belligerence among the primitives: A re-analysis of Quincy Wright's data. Journal of Peace Research, 3, 1, pp. 33-45.

Buss, D.M (1999) Evolutionary Psychology: The New Science of the Mind. Boston: Allyn & Bacon.

Cashdan, E.A. (1983) Territoriality among human foragers: Ecological models and an application to four Bushman groups. Current Anthropology, 24, 1, pp. 47-66.

Chagnon, N.A. (1968) Yanomamö: The Fierce People. New York: Holt, Rinehart & Winston.

Cheney,  D.L. (1987) Interactions and relationships between groups. In: B.B. Smuts, D.L. Cheney, R.M. Seyfarth, R.W. Wrangham & T.T. Struhsaker (Eds.) Primate Societies. University of Chicago Press, pp. 267-281.

Cioffi-Revilla, C. (1996) Origins and evolution of war and politics. International Studies Quarterly, 40, pp. 1-22.

Cioffi-Revilla, C. (2000) Ancient warfare: Origins and systems. In: M.I. Midlarsky (Ed.) Handbook of War Studies II. Ann Arbor: University of Michigan Press,  pp. 59-89.

Cooper, J.M. (1946) The Yahgan; The Ona. In: J.H. Steward (Ed.) Handbook of South American Indians. Vol. 1. Washington: US Government Printing Office, pp. 81-106; 107-126.

Corning, P. (2003) Nature’s Magic: Synergy in Evolution and the Fate of Mankind  Cambridge: Cambridge University Press.

Coser, L.A. (1956) The Functions of Social Conflict. New York: Free Press.

Davie, M.R. (1929) The Evolution of War: A Study of its Role in Early Societies. New Haven CT: Yale University Press.

Dentan, R.K. (1968/1979) The Semai: A Nonviolent People of Malaya. New York: Holt, Rinehart & Winston.

Driver, H.E. (1969) Indians of North America. Chicago: University of Chicago Press.

Dyer, G. (1985) War. New York: Crown.

Eckhardt, W. (1975) Primitive militarism. Journal of Peace Research, 12, 1, pp. 55-62.

Eckhardt, W. (1982) Atrocities, civilizations, and savages: Ways to avoid a nuclear holocaust. Bulletin of Peace Proposals, 13, 4, pp. 343-50.

Ehrenreich, B. (1997) Blood Rites: Origins and History of the Passions of War. New York: Metropolitan Books.

Eibl-Eibesfeldt, I. (1975) Krieg und Frieden aus der Sicht der Verhaltensforschung. München: Piper Verlag.

Elsasser, A.B. (1978) Wiyot; Mattole, Nongatl, Sinkyone, Lassik, and Wailaki. In: Heizer (Vol. Ed.), pp. 155-63; 190-204.

Ember, C.R. (1978) Myths about hunter-gatherers. Ethnology, 17: 439-48.

Ember, C.R. & M. Ember (1992) Resource unpredictability, mistrust, and war: A cross-cultural study. Journal of Conflict Resolution, 36, 2, pp. 242-62.

Ember, C.R. & M. Ember (1997) Violence in the ethnographic record: Results of cross-cultural research on war and aggression. In: D.L. Martin & D.W. Frayer (Eds.) Troubled Times: Violence and Warfare in the Past. Amsterdam: Gordon & Breach, pp. 1-20.

Endicott, K.L. (1999) Gender relations in hunter-gatherer societies. In: R.B. Lee & R. Daly (Eds.) The Cambridge Encyclopedia of Hunters and Gatherers. Cambridge: Cambridge University Press, pp. 411-418.

Falger, V.S.E. (1994) Evolutie en politiek: biopoliticologische opstellen. Groningen: Origin Press.

Ferguson, R.B. (Ed.) (1984) Warfare, Culture and Environment. New York: Academic Press.

Ferguson, R.B. (1990) Explaining war. In: J. Haas (Ed.) The Anthropology of War. Cambridge: Cambridge University Press, pp. 26-55.

Freeman, D. (1983) Margaret Mead and Samoa: The Making and Unmaking of an Anthropological Myth. Cambridge, MA: Harvard University Press.

Fuller, J.F.C. (1970) The Decisive Battles of the Western World. 2 Vols. St Albans: Paladin.

Gat, A. (2000) The human motivational complex: Evolutionary theory and the causes of hunter-gatherer fighting. Anthropological Quarterly, 73, pp. 20-34, 74-88.

Ghiglieri, M.P. (1999) The Dark Side of Man: Tracing the Origins of Male Violence. Reading, MA: Perseus.

Goodall, J. (1986) The Chimpanzees of Gombe: Patterns of Behavior. Cambridge MA: Belknap Press.

Goodall, J., A. Bandora, E. Bergmann, C. Busse, H. Matama, E.Mpongo, A. Pierce & D. Riss (1979) Inter-community interactions in the Chimpanzee population of the Gombe Naional Park. In: D.A. Hamburg & E.R. McCown (Eds.) The Great Apes. Menlo Park: Benjamin/Cummings, pp. 13-53.

Gusinde, M. (1937) The Yahgan: The Life and Thought of the Water Nomads of Cape Horn. New Haven: HRAF.

Hart, C.W.M. & A.R. Pilling (1979) The Tiwi of North Australia. New York: Holt, Rinehart & Winston.

Heizer, R.F. (Vol. Ed.) (1978) Handbook of North American Indians. Vol. 8: California. Washington DC: U.S. Government Printing Office.

Hobhouse, L.T. (1956) The simplest peoples. Part II: Peace and order among the simplest peoples. British Journal of Sociology, 7, pp. 96-119.

Hobhouse, L.T.; G. Wheeler & M. Ginsberg (1915) The Material Culture and Social Institutions of the Simpler Peoples. London: London School of Economics Monographs on Sociology 3.

Hoebel, E.A. (1967) The Law of Primitive Man: A Study in Comparative Legal Dynamics. Cambridge, MA: Harvard University Press.

Honigmann, J.J. (1954) The Kaska Indians: An Ethnographic Reconstruction. New Haven: Yale University Press.

Horton, D. (1994) Warfare. In: D. Horton (Ed.) The Encyclopedia of Aboriginal Australia. Vol. 2, Canberra: Aboriginal Studies Press, pp. 1152-1154.

Jorgensen, J.G. (1989) Western Indians: Comparative Environments, Languages and Cultures of 172 Western American Indian Tribes. San Francisco: Freeman.

Keegan, J. (1993) A History of Warfare. London: Hutchinson.

Keeley, L.H. (1996) War Before Civilization: The Myth of the Peaceful Savage. New York: Oxford Univ. Press.

Keeley, L.H (2006) Book review of Otterbein How War Began. Journal of Interdisciplinary History, 37, 2, pp. 261-262.

Kelly, R.C. (2000) Warless Societies and the Origin of War. Ann Arbor: University of Michigan Press.

Knauft, B.M. (1987) Reconsidering violence in simple human societies: Homicide among the Gebusi on New Guinea. Current Anthropol. 28, 4, pp. 457-500.

Kortlandt, A. (1972) New Perspectives on Ape and Human Evolution. Amsterdam: Stichting voor Psychobiologie.

Kroeber, A.L. (1928) A Kato war. In: W. Koppers (Ed.) Festschrift P.W. Schmidt. Wien, pp. 394-400.

Leavitt, G.C. (1977) The frequency of warfare: An evolutionary perspective. Sociological Inquiry, 47, pp. 49-58.

Lenski, G. & J. Lenski (1978) Human Societies: An Introduction to Macrosociology. New York: McGraw-Hill.

Livingstone, F.B. (1968) The effects of warfare on the biology of the human species. In: Fried, M.H.; M. Harris & R. Murphy (Eds.) War: The Anthropology of Armed Conflict and Aggression. New York: Natural History Press pp. 3-15.

Low, B.S. (1993) An evolutionary perspective on war. In: W. Zimmerman & H. Jacobson (Eds.) Behavior, Culture, and Conflict in World Politics. Ann Arbor: University of Michigan Press, pp. 13-55.

McCorkle, T. (1978) Intergroup conflict. In: Heizer (Vol. Ed.), pp. 694-700.

Meggitt, M. (1965) Desert People: A Study of the Walbiri Aborigines of Central Australia. Chicago: University of Chicago Press.

Meyer, P. (1981) Evolution und Gewalt. Ansätze zu einer bio-soziologischen Synthese. Hamburg: Parey Verlag.

Mühlmann, W.E. (1940) Krieg und Frieden. Ein Leitfaden der politischen Ethnologie. Heidelberg: C.Winters Universitätsbuchhandlung.

Murdock, G.P. (1934) Our Primitive Contemporaries. New York: Macmillan.

Murdock, G.P. (1967) Ethnographic Atlas. Pittsburgh: University of  Pittsburgh Press.

Murdock, G.P. (1981) Atlas of World Cultures. Pittsburgh: University of Pittsburgh Press.

Myers, J.E. (1978) Cahto. In: Heizer (Vol. Ed.), pp. 244-48.

Nolan, P.D. (2003) Toward an ecological-evolutionary theory of the incidence of warfare in preindustrial societies. Sociological Theory, 21, 1, pp. 18-30.

Osgood, C.B. (1958) Ingalik social culture. Yale University Publications in Anthropology, 53.

Otterbein, K.F. (1968) Cross-cultural studies of armed combat. Buffalo Studies, 4, 1, pp. 91-109.

Otterbein, K.F. (1970) The Evolution of War: A Cross-Cultural Study. New Haven: HRAF Press.

Otterbein, K. (1991) Comments on “Violence and sociality in human evolution” by B.M. Knauft. Current Anthropology, 32: 414.

Otterbein, K.F. (1997) The origins of war. Critical Review, 2, 1997, pp. 251-277.

Prosterman, R.L. (1972) Surviving to 3000: An Introduction to the Study of Lethal Conflict. North Scituate: Duxbury Press.

Radcliffe-Brown, A.R. (1922) The Andaman Islanders. Cambridge: Cambridge University Press.

Robarchek, C.A. & C.J. Robarchek (1989) The Waorani: From warfare to peacefulness. The World and I, 4, 1, pp. 625-35.

Rudmin, F.W. (1990) Cross-cultural correlates of war. Peace Research, 22, 2, pp. 9-16.

Schaller, G.B. (1972) The Serengeti Lion: A Study of Predator-Prey Relations. Chicago: Chicago University Press.

Service, E.R. (1966) The Hunters. Englewood Cliffs: Prentice Hall.

Service, E.R. (1975) Origins of the State and Civilization: The Process of Cultural Evolution. New York: Norton.

Shaw, R.P. & Y. Wong (1989) Genetic Seeds of Warfare: Evolution, Nationalism, and Patriotism. London: Unwin Hyman.

Simmons, L.W. (1937) Statistical correlations in the science of society. In: G.P. Murdock (Ed.) Studies in the Science of Society. New Haven: Yale Universsity Press, pp. 493-517.

Spencer, B. & F.J. Gillen (1927) The Arunta: A Study of a Stone Age People. 2 Vols. London: Macmillan.

Sponsel, L.E. (1996) The natural history of peace: A positive view of human nature and its potential. In: T. Gregor (Ed.) A Natural History of Peace. Nashville, TN: Vanderbilt University Press, pp. 95-125.

Sumner, W.G. (1911) War and Other Essays. New Haven: Yale University Press.

Sumner, W.G. & A.G. Keller (1927) The Science of Society. 4 Vols. New Haven: Yale University Press.

Symons, D. (1979) The Evolution of Human Sexuality. Oxford: Oxford University Press.

Textor, R.B. (1967) A Cross-Cultural Summary. New Haven: HRAF Press.

Thayer, B.A. (2004) Darwin and International Relations: On the Evolutionary Origins of War and Ethnic Conflict. Lexington: University of Kentucky Press.

Thoden van Velzen, H.U.E. & W. van Wetering (1960) Residence, power groups and intra-societal aggression: An inquiry into the conditions leading to peacefulness within non-stratified societies. International Archives of Ethnography, 49, pp. 169-200.

Tonkinson, R. (1978) The Mardu(djara) Aborigines: Living the Dream in Australia's Desert. New York: Holt, Rinehart & Winston.

Tonkinson, R. (2004) Resolving conflict within the law: The Mardu Aborigines of Australia. In: G. Kemp & D.P. Fry (Eds.) Keeping the Peace: Conflict Resolution and Peaceful Societies around the World. New York: New York: Routledge, pp. 89-104.

Toynbee, A.J. (1950) War and Civilization. New York: Oxford University Press.

Turney-High, H.H. (1949) Primitive War: Its Practice and Concepts. Columbia: University of South Carolina Press.

Van der Bij, T.S. (1929) Ontstaan en eerste ontwikkeling van den oorlog. Groningen: Wolters.

Van der Dennen, J.M.G. (1995) The Origin of War: The Evolution of a Male-Coalitional Reproductive Strategy. 2 Vols. Groningen: Origin Press.

Van der Dennen, J.M.G. (2002) (Evolutionary) Theories of Warfare in Preindustrial (Foraging) Societies. Neuroendocrinological Letters, Spec. issue, 23, Suppl. 4, 55-65.

Van der Dennen (2002) Warfare. In: M. Pagel (Ed.-in-chief) Oxford Encyclopedia of Evolution, Vol. 2, pp. 1146-1149.

Warner, W.L. (1969) A Black Civilization: A Social Study of an Australian Tribe. New York: Harper.

Westermarck, E. (1910) Prefatory note. In: Wheeler (1910).

Wheeler, G.C. (1910) The Tribe, and Intertribal Relations in Australia. London: Murray.

Wilkinson, P.F. & C.C. Shank (1976) Rutting-fight mortality among musk oxen on Banks Island, Northwest Territories, Canada. Animal Behavior, 24, 4, pp. 756-758.

Williams, N.M. (1987) Two Laws: Managing Disputes in a Contemporary Aboriginal Community. Canberra: Australian Institute of Aboriginal Studies.

Wilson, E.O. (1978) On Human Nature. Cambridge MA: Harvard University Press.

Wilson, M.L. & R.W. Wrangham (2003) Intergroup relations in chimpanzees. Annual Review of  Anthropology, 32, pp. 363-392.

Wrangham, R.W. (1999a) Is military incompetence adaptive? Evolution and Human Behavior, 20, pp. 3-17.

Wrangham, R.W. (1999b) Evolution of coalitionary killing. Yearbook of Physical Anthropology, 42, pp. 1-30.

Wrangham, R.W. & D. Peterson (1996) Demonic Males: Apes and the Origin of Human Violence. Boston: Houghton Mifflin.

Wrangham, R.W.; M.L. Wilson & M.N. Muller (2006) Comparative rates of violence in chimpanzees and humans. Primates, 47, pp. 14-26.

Wright, Q. ([1942] 1965) A Study of War. Chicago: University of Chicago Press.

Table 1: Warring versus Nonwarring and Type of Society

Simple nomadic hunter-gatherers are in the top row. Other types of hunter-gatherers complex and equestrian) are in the bottom row. Following Prosterman and Otterbein, war is defined as involving armed combat between political communities and not merely as feuding and revenge homicide. Societies are classified based on Murdock’s codes. The results are highly significant.

Nonwarring (n = 13)


Warring (n = 22)


Simple Hunter-gatherers


Copper Eskimo



Other Hunter-gatherers


Bella Coola
Gros Ventre
Chiricahua Apache
Eastern Pomo


Fisher’s exact test (one-tailed) probability, p = .0001

Table after Fry (2006: 106)

CV: Johan M.G. van der Dennen, Ph.D.

Dr Johan M.G. van der Dennen studied behavioral sciences at the University of Groningen, and is at present a senior researcher at the Section Political Science of the Department of Legal Theory, formerly the Polemological (Peace Research) Institute, University of Groningen, the Netherlands. He has published extensively (more than 200 publications) on all aspects of human and animal aggression, sexual violence, neuro- and psychopathology of human violence, political violence, criminal violence, theories of war causation, macro-quantitative research on contemporary wars, ethnocentrism, and the politics of peace and war in preindustrial societies. In 1995 he published his dissertation “The Origin of War: The Evolution of A Male-Coalitional Reproductive Strategy”, an evolutionary analysis of the origin of intergroup violence in humans and animals.
Works in progress: Ongoing research on the politics of peace and war in preindustrial societies; violent intergroup competition (Intergroup Agonistic Behavior) in social animals; genocide and war atrocities in contemporary human societies; sexual violence in animals and man; and the origin of war in hominid/human phylogeny.
Some recent books:
J.M.G. van der Dennen & V.S.E. Falger (Eds.) (1990) Sociobiology and Conflict: Evolutionary Perspectives on Competition, Cooperation, Violence and Warfare. Chapman & Hall, London;
J.M.G. van der Dennen (Ed.) (1992) The Nature of the Sexes: The Sociobiology of Sex Differences and the ‘Battle of the Sexes’ (Essays in Human Sociobiology, Vol. 3). Origin Press, Groningen;
H. Caton; F.K. Salter & J.M.G. van der Dennen (Eds.) (1993) The Bibliography of Human Behavior. Greenwood Press, Westport CT;
J.M.G. van der Dennen (1995) The Origin of War: The Evolution of a Male-Coalitional Reproductive Strategy. 2 Vols., Origin Press, Groningen;
V.S.E. Falger; P. Meyer & J.M.G. van der Dennen (Eds.) (1998) Sociobiology and Politics, JAI Press, Greenwich CT;
J.M.G. van der Dennen; D. Smillie & D.R. Wilson (Eds.) (1999) The Darwinian Heritage and Sociobiology. Praeger/Greenwood Press, Westport CT;