Of Badges, Bonds and Boundaries:
Ingroup/outgroup differentiation and ethnocentrism revisited

by Johan M.G. van der Dennen, Center for Peace and Conflict Studies, University of Groningen, The Netherlands


At the fifth Annual Meeting of the European Sociobiological Society (ESS), St. John's College, Oxford, U.K. (January 5-6, 1985), I presented the following paper:

"I present a literature review of theories and research concerning the phenomena of ethnocentrism, ingroup/outgroup differentiation, moralistic aggression, xenophobic aggression, collective intolerance, and intergroup violence, all of which are regarded as parts of one complex and composite syndrome. An attempt to interpret the ethnocentrism syndrome as a symbol-system-cum-sentiment-structure is offered, and its value as an explanatory category for the causation of 'primitive' warfare is assessed" (The paper was published as "Ethnocentrism and in-group/out-group differentiation" in: V. Reynolds, V. Falger & I. Vine (Eds.) The Sociobiology of Ethnocentrism: Evolutionary dimensions of xenophobia, discrimination, racism and nationalism, 1987, pp. 1-47).

In this paper I intend to revisit this literature and research, and especially what has been added since that time (in particular the important Shaw & Wong (1989) Genetic Seeds of Warfare monography and Anne Katrin Flohr's (1994) Fremdenfeindlichkeit: biosoziale Grundlagen von Ethnozentrismus. I shall also attempt to assess the value of sociobiological or evolutionary ethnocentrism theory to account for the origin of warfare and intergroup violence in general.


In order to appreciate what is so special about human group phenomena and ethnocentrism, I start by presenting some observations on human (collective) violence generally.
Violence in and between human societies, with the exception of some forms of domestic, criminal and pathological violence, is virtually always a collective activity or committed in the name of a collectivity.
Collective violence is covered with a thick patina of self-justification, ratiomorphic nonsense and pathos. "Men will die like flies for theories and exterminate each other with every instrument of destruction for abstractions" (Durbin & Bowlby, 1938). The most extensive, quixotic and disgusting violence is justified with the invocation of a utopian ideology, a paradise myth, a superiority doctrine, an eschatological or millenarian ideal state, or other highly abstract political/ethical categories, metaphysical values, and quasi-metaphysical mental monstrosities: National Security, Raison d'Etat, Freedom, Democracy, God, Volk und Heimat, Blut und Boden, Peace, Progress, Empire, Historical Imperative, Sacred Order, Natural Necessity, Divine Will, and so on and so forth. The human being as the 'most ferocious of beasts' as William James called him, is only a beast in the name of some superhuman ideal, which serves as a 'sanction for evil' (Sanford & Comstock, 1971); divine or diffuse permission for large-scale destructiveness. The purity and sacredness of our cause, and the divine sanction of our actions ('with God on our side') is guaranteed by the wickedness of the enemy, who is envisaged as the incorporation of evil, the devil incarnate.
This moral double standard leads to the masquerading of the violence committed in the name of one's own in-group as justified self-defense, or as a well-deserved punishment for transgressions of mores, laws, or ideological orthodoxy. The violence may range from sanctions against a dissenter or potential renegade within the group, to punitive expeditions, and even genocide, between groups.
Total identification with the group makes the individual perform altruistic acts to the point of self-sacrifice, and at the same time behave with ruthless cruelty towards the enemy or victim of the group. As Koestler (1967) observed: the self-assertive behavior of the group is based on the self-transcending behavior of its members. The egotism of the group feeds on the altruism of its members.

Cultural pseudospeciation.
Erikson's (1964) concept of cultural pseudospeciation denotes the fact that while Man is obviously one species, he appears on the scene split into groups which provide their members with a firm sense of distinct and superior identity.
Man is the cultural animal par excellence. All members of the (sub)species Homo sapiens sapiens share the characteristic of being capable to create, and be created by, culture. At the same time, however, culture is the great unbalancer, the great catalyst of diversity and reinforcer of differences, underlying universal human cultural pseudospeciation. Owing to this process, human groups (be they ethnies, tribes or nations) tend to differ from one another to such a degree that the groups come to perceive each other as though they were totally different species (e.g, Willhoite, 1977).
Especially Tinbergen (1968, 1981) has pointed out how violence changes in character from intraspecific aggression to interspecific predation the more the enemy is dehumanized and 'pseudospeciated'. No holds are barred in hunting down a foreign species.
MacCurdy (1918) foreshadowed this valuable concept of pseudospeciation in his Psychology of War. According to him, early tribal warfare had fixed the idea that strangers were another species, and thus was overcome the natural inhibition against killing conspecifics. Humans by their "herd nature" were doomed to split into groups, and these groups behaved biologically like separate species struggling for existence. During times of war, he suggested, humans still felt vestigial emotions of hostility to their enemies as species other than themselves (Crook, 1994).

Due to his elaborate cognitive capacity Man has the ability to create psychological 'distancing devices', to dehumanize, diabolize, to exterminate his enemies like vermin in fantasy and in reality; and to generate Weltanschauungen in which only a small portion of humanity fits, and social paradises from which the 'misfits' have to be expelled.
Together with the concept of cultural pseudospeciation, dehumanization (the perception or definition of other people as less than human or even nonhuman) is probably the most important proximate concept for understanding malignant (mass)violence phenomena, including 'ethnic cleansing', war atrocities, massacres and genocide, in humans (and probably as 'dechimpization' [Goodall, 1986] in chimpanzees as well). There is a profound paradox involved in the process of dehumanization in the sense that one can only dehumanize what is recognized and acknowledged to be human in the first place.
Volkan (1992) and Galtung (1994) identify, besides dehumanization, two more elements in the group dynamics toward violence and war: the 'Chosen Trauma' and the 'Chosen Glory' of the group, leading to the intergenerational transmission of historical enmity.


Ethnocentrism is considered to be a schismatic in-group/out-group differentiation, in which internal cohesion, relative peace, solidarity, loyalty and devotion to the in-group, and the glorification of the sociocentric-sacred (the own cosmology, ideology, social myth, or Weltanschauung; the own 'godgiven' social order) is correlated with a state of hostility or permanent quasi-war (status hostilis) toward out-groups, which are often perceived as inferior, subhuman, and/or the incorporation of evil. Ethnocentrism results in a dualistic, Manichaean morality which evaluates violence within the in-group as negative, and violence against the out-group as positive, even desirable and heroic.
This is, admittedly, a rather extreme definition. The usual dictionary definition of ethnocentrism is "the tendency to regard one's own group and culture as intrinsically superior to all others" (Webster's Dictionary). Superiority of the own group and culture, however, (psycho)logically implies inferiority of other groups and cultures. And viewing other groups/cultures as inferior empirically appears to imply some degree (however small) of contempt, stereotyping, discrimination and dehumanization of, and at least a modicum of hostility toward, members of those other groups/cultures. Ethnocentrism and its canonical variants (tribalism, nationalism, etc.) also appears to be intimately connected with xenophobia, a complex attitude system-cum-sentiment structure involving dislike, distrust, aversion, revulsion, fear and antagonism vis-à-vis strangers/foreigners/aliens and everything the stranger/foreigner/alien represents (though, as Van den Berghe (1997) pointed out, "ethnocentrism does not automatically and invariably imply xenophobia").
Two forms of the ethnocentric syndrome must probably be distinguished: (1) A belligerent, megalomaniac, superiority-delusional form (Chosen People complex), and (2) a relatively peaceful, self-conceited, isolationist form (e.g., the Han Chinese vis-à-vis the peripheral peoples).
Hardin (1972) introduced the related concept of tribalism: "Any group of people that perceives itself as a distinct group, and which is so perceived by the outside world, may be called a tribe. The group might be a race, as ordinarily defined, but it need not be; it can just as well be a religious sect, a political group, or an occupational group. The essential characteristic of a tribe is that it should follow a double standard of morality - one kind of behavior for in-group relations, another for out-group".
Other authors use terms like 'group egoism', 'groupism', etc. in a similar sense.
There are two prevailing views of the fundamental nature of ethnicity. One emphasizes the ascriptive, or primordial, nature of ethnic group membership and the importance of kinship, early socialization, and strong emotional ties. The other insists that ethnicity is situationally defined, that ethnic group boundaries are malleable and permeable, and that ethnicity may be acquired or divested at will (Richmond, 1987). This has been called the instrumentalist position. Van den Berghe (1981) has attempted to show that the primordialist-instrumentalist controversy is based on a simple-minded antinomy, and that the two views complement rather than contradict each other.

Ethnocentrism: Brief History of the Concept

In 1767 the Scottish philosopher Adam Ferguson published an Essay on the History of Civil Society, probably the first attempt at an empirical investigation of the origins of war using ethnographic data. His analysis seemed to confirm Hobbes (1651): the primitive state was indeed a state of war (status hostilis): "We have had occasion to observe, that in every rude state the great business is war; and that in barbarous times, mankind, being generally divided into small parties, are engaged in almost perpetual hostilities" (Essay 3.5).
In addition to maintaining the balance-of-power between societies, Ferguson ascribes to warfare the function of maintaining solidarity and morale within societies. In-group amity depends upon out-group enmity and vice versa. This idea could also be found, in primordial form, in classical authors (Dawson, 1996), but Ferguson probably offers the first analysis of the phenomenon of ethnocentrism in history.
Though the term 'ethnocentrism' was to be coined a few decades later, the concept was by no means unknown among 19th century anthropologists such as Tylor (1871), who viewed ethnocentrism (as well as the obligations of the blood feud) as making sense within a framework of primitive concepts of law and justice.
Also Darwin (1871) had noticed that contemporary 'primitive' peoples as a rule confined their sympathy to the own tribe and generally did not regard violence against other tribes as a crime. He clearly saw the correlation between intergroup competition and intragroup cooperation, which is the core of the ethnocentrism syndrome, in human evolution. So did his contemporaries such as Comte (1869), Spencer (1850 et seq.), Bagehot (1872) and Gumplowicz (1883).
Spencer (1892) discovered that evolution, as seen to work in human communities, spoke with two voices, each enunciating a separate code. He called the one the 'Code of Amity' (conducive to harmonious within-group cooperation), and the other the 'Code of Enmity' (conducive to constant between-group enmity and revenge).
Sumner (1906; 1911), who later coined the term 'ethnocentrism' for this dual code of conduct, heavily implicated ethnocentrism, and its collateral xenophobia, in the evolution of warfare. In his Folkways, Sumner (1906), echoing Spencer and Bagehot, writes: "The exigencies of war with outsiders are what make peace inside, lest internal discord should weaken the in-group for war. The exigencies also make government and law in the in-group, in order to prevent quarrels and enforce discipline".
Subsequently, Sumner (1911) notes that "Perhaps nine-tenths of all the names given by savage tribes to themselves mean 'men', 'the only men', or 'men of men'; that is, 'We are men, the rest are something else'... Religion has always intensified ethnocentrism; the adherents of a religion always think themselves the chosen people, or else they think that their god is superior to all others, which amounts to the same thing (Sumner, 1911).
In his Folkways, Sumner (1906) had already emphasized this superiority-delusional aspect of ethnocentrism, which he regarded as universal, in describing it as "this view of things in which one's own group is the center of everything, and all others are scaled and rated with reference to it... Each group nourishes its own pride and vanity, boasts itself superior, exalts its own divinities, and looks with contempt on outsiders".
The next author, after Sumner, to elaborate the theme of ethnocentrism in relation to primitive warfare was Davie (1929), who sketched a truly Hobbesian picture of the 'savage' world, pointing out that the relation of primitive groups to one another is one of isolation, suspicion, hostility and war; a status hostilis, if not a regular status belli. Yet within the tribe the common interest against every other tribe compels its members to unite for self-preservation. "Thus a distinction arises between one's own tribe - the 'in-group' - and other tribes - the 'out-group'; and between the members of the first peace and cooperation are essential, whereas their inbred sentiment toward all outsiders is one of hatred and hostility. These two relations are correlative".
Thus Davie did not add much to Sumner's arguments in terms of theoretical sophistication. He did, however, summarize the then available ethnological evidence from all over the world. In the accounts of contemporary anthropologists, the theme or Leitmotif of ethnocentrism, whether implicit or explicit, is clearly recognizable (e.g., Murphy, 1957, 1960; Rappaport, 1968; Koch, 1974; Huber, 1975; Chagnon, 1977; Herdt, 1981; Paula Brown, 1982; Knauft, 1983; among many others).
The Yanomanö fierceness, for example, derives, at least in part, from their belief that they were the first, finest and most refined form of man to inhabit the earth, and that all other peoples are a degeneration from their pure stock (Keegan, 1993: 97). Another Amazonian people, the Mundurucu (who waged headhunting raids against all of their neigbors) , consider other people to be on the same level as their principal game food, the peccary. Their word for enemy (pariwat) merely meant any group that was not Mundurucu (Murphy, 1957, 1960).
Such a state of affairs has resulted in the isolation of many primitive peoples, their ignorance of one another, and the great variation in their mores and languages. As Bigelow (1972) suggests: "When they cannot understand one another beyond the level of smiles and grunts and blatant gestures, people rarely achieve deep cultural bonds and common loyalties".
Sumner's thesis has, by now, been supported by a substantial body of evidence (e.g., Murdock, 1949; Catton, 1961; LeVine & Campbell, 1972; Van den Berghe, 1981; Reynolds, Falger & Vine, 1987; Shaw & Wong, 1989; A. Flohr, 1994).

Ethnocentrism and Nationalism

Ethnocentrism is not a monopoly of primitive peoples. It is also a common theme, in the guise of nationalism, in the history of civilization.
Bauer (1907) defined a nation as a community shaped by shared experiences. The nation is a Schicksalsgemeinschaft - a community united by a common fate. This is, psychologically, a much more sensible conception of the nation than the formal definitions of the political scientists.
The cognitive approach to nationalism, as exemplified by Hobsbawm (1990), regards it as a historical phenomenon concomitant with the rise and decline of the nation-state. This approach would deny any primordial, individual human propensity to one form of ethnocentrism or another. The rational choice, marginal utility, and transactional theories of ethnic and nationalist identification do not, however, take into consideration the often irrational, passionate animosities, equally passionate loyalties, strong affective attachments to sacred symbols and myths, threat perceptions, and other emotional aspects involved. All too often in human affairs passion overrides reason, and ethnophobias turn into hatred, hostility, and violence (Loewenberg, 1994; Richmond, 1987). As Falger (1991, 1994) reasoned, the view of nationalism as a recent historical phenomenon is valid only for those who are insensitive to its underlying ultimate dimension. The association of nationalism with the nation-state is indeed relatively recent, but it is only one phenotypic expression of the deep in-group/out-group structure inherited from human prehistory.
In a recent perceptive contribution to the problem of (ethnic) nationalism, Ignatieff (1994) notes that nationalism is everywhere characterized by a deeply insincere and unauthentic rhetoric functioning as an excuse for excesses and atrocities. Everywhere historical truth is the 'first casualty'.
Wilson & Daly (1985) and Daly & Wilson (1987) noted the preponderance of young males in all kinds of criminal violence. They called it the "Young Male Syndrome". Ignatieff noticed that most nationalist violence, too, is committed by a small minority of young males (some of whom may be psychopathic; most, however, are perfectly sane). Apparently not everyone abhors or fears violence. Presumably, it is deeply pleasurable and satisfactory for young armed males to have the power of life and death over other people; to fanatically assert themselves at the cost of others and to escape from insignificance; to rebel against and disrupt the deeply resented order of the state; to massively rape; to psychologically and morally and phylogenetically regress (see Bailey, 1987, for the theory of phylogenetic regression).
Wrangham & Peterson (1996) note that the underlying psychology is no different for urban gangs, pre-state warrior societies, and contemporary armies: Bands of males "sight or invent an enemy 'over there' - across the ridge, on the other side of the boundary, on the other side of a linguistic or social or political or ethnic or racial divide. The nature of the divide hardly seems to matter. What matters is the opportunity to engage in the vast and compelling drama of belonging to the gang, identifying the enemy, going on the patrol, participating in the attack" (italics added).
Tiger (1969) had already formulated a similar idea: "Put a group of males together and, once dominance order is established, the group will either split into competing coalition units or seek some exterior object for collective 'masterful' action... While legal systems deal with the individual as the unit for guilt and innocence, it is really the group which is at the heart of all but a small proportion of criminal proceedings".
The special blend of militant nationalism, pugnacious patriotism, and expansionist imperialism is called jingoism. In his The Psychology of Jingoism, Hobson (1901) attributed it to man's 'ancient savage nature' lurking somewhere in 'sub-conscious depths', under the superstructure or thin veneer of civilization. He spoke of the "animal hate, vindictiveness, and bloodthirstiness" that lurked in the mildest-mannered patriot.

The Adaptive Significance of Xenophobia

There is an analogy, according to Rosenblatt (1964), between immunological reactions of the body and the ethnocentric reactions of the individual or of a society.

Just as the body is better prepared to avoid destruction by foreign substances as a result of a generalized tendency to resist the impingement of foreign substances, so an individual or a society may be better prepared to avoid destruction by aliens as a result of a generalized tendency to distrust, avoid, or reject apparently foreign individuals. The disadvantage of severe damage or destruction, whether likely to occur or not, is so much greater than whatever advantages contact with things alien confers on one, that a psychological or biochemical paranoia is the preferred strategy for survival. Where one failure to anticipate the malevolence of an alien person or substance may be fatal, organisms that must acquire defensive reactions to each specific harmful person or substance are less likely to survive during a given period of time than organisms prepared to be defensive against all alien persons or substances (Rosenblatt, 1964)

Also Lumsden & Wilson (1983), Barash & Lipton (1985), H. Flohr (1987), and Shaw & Wong (1989) postulated an adaptive significance of (mildly) paranoid thinking. In situations of strong intergroup competition, they explain, the payoff for vigilance and suspiciousness could be substantial. "A genetically coded aversion toward strangers would have enabled individuals to avoid attack more readily or immediately than would learning alone, and by avoiding injury and death, survival would be enhanced, leaving more offspring from these individuals. Over time, those with the genetically coded aversion toward strangers would come to prevail in the population" (Shaw & Wong, 1989).
MacDonald (1992) has probably explained the rationale underlying the paranoid stance most clearly. From an evolutionary perspective, he says, it would appear to be adaptive to exaggerate negative stereotypes about a genetically segregated group, or accept negative information based on minimal evidence, or to develop a generalized negative belief about an out-group which is based on the behavior of only a small minority of the out-group. Such a perspective can be seen to conform to a simple cost/ benefit analysis: members of Group A benefit by erring on the side of preventing the error of rejecting a negative proposition regarding members of group non-A, when it could be true. In the language of statistics, people are proposed to behave as if attempting to minimize the probability of a Type II error: if the hypothesis is "Members of Group A are disloyal", people appear to be greatly concerned about making the error of rejecting this proposition when in fact it could be true. They place less emphasis on making a Type I error, which is the probability of accepting the proposition "Members of Group A are disloyal" when in fact they are loyal. The cost/benefit reasoning is that making a Type II error could be extremely costly, while making a Type I error costs little or nothing.
The general principle here is that if one knows that at least some members of a group are deceivers, but does not know exactly which ones, the best policy it to assume that all are deceivers if this policy has no negative consequences.
Such a strategy also makes good evolutionary sense for the explanation of the overperception of threat. An organism contemplating sine ira et studio every new situation arising in its immediate environment probably would not survive its first encounter with a predator. An evolutionary strategy of being overcautious - jumping to conclusions given the slightest indication of danger - thus pays off in terms of survival and reproductive success, and may therefore be expected to be selected for.
Xenophobia is a widespread trait throughout the animal kingdom, according to Southwick et al. (1974), but it is by no means universal. Among vertebrates, xenophobic aggression has been demonstrated experimentally in a great number of species, especially those with prominent territorial and/or relatively closed social groups, which are organized on a hierarchical basis (e.g., Holloway, 1974; Southwick et al., 1974; E.O. Wilson, 1971, 1975; see Van der Dennen [1987] for a review). The introduction of unfamiliar conspecifics to such groups (e.g., rodents and many primate species) may release massive attacks and even killing from the resident animals. Xenophobia has apparently evolved in those species where discrete, bounded social groups are adaptively favored (Southwick et al., 1974).
Also Hebb & Thompson (1968) cite the evidence in favor of the mammal's xenophobia; the fear of and hostility towards strangers, even when no injury has ever been received from a stranger. The enmity aroused by conspecifics which are different (in anatomy, in coloration, in behavior, in language use) or by strangers, may easily lead toward discrimination, ostracism and cruelty in animals as well as man.
Markl (1976) deduced the following general rule from observations such as these: Species with highly cooperative social behavior within the group are particularly apt to be very aggressive towards conspecifics that are not members of their group.
McGuire (1969), among others, discussed the possible genetic transmission of xenophobia. On the other hand, Hebb & Thompson (1968) argued that fear or dislike of the stranger is not innate, since it depends on certain prior experiences, yet it still does not have to be taught. "If, therefore, man is not born with a dislike for those who differ from him in habits or appearance, he can still pick up the dislike with no help or encouragement" (Hebb & Thompson, 1968).
Also Hamilton (1975) and Alexander (1979) argue that social interactions of an individual with his close relatives can provide all of the experiential background necessary to produce xenophobia. We tend to react negatively to countenances which are uncommunicative, and which convey contradictory or paradoxical messages.
It is not clear whether the transient phenomenon of the fear of strangers in infants - which predictably develops between 6 and 9 months of age - has any impact on adult xenophobia (See e.g., A. Flohr, 1994). Such infantile fear of strangers is also reported in other social species (e.g., canids), and its development does not depend upon aversive experience with strangers (the ancestors of contemporary dogs, wild wolves, were and still are - like humans - highly social, group-territorial, and intolerant toward 'outsiders'). Furthermore, fear of strangers also develops in congenitally deaf and blind children (e.g., Eibl-Eibesfeldt, 1982).
Although the expression of these predispositions varies, Emmert (1984) and Shaw & Wong (1989) conclude, it seems that initial distrust of social strangers is universal among humans and nonhuman primates. Also H. Flohr (1987) concludes that xenophobia seems to be universal, i.e., it seems to occur in all cultures. This is no proof, he states, but strong evidence in favor of a biological basis of xenophobia (cf. Markl, 1982; A. Flohr, 1994). The biological basis concerns, of course, the tendency towards xenophobic prejudices, not their specific content.
Peck (1990) has shown through formal models that mechanisms of outsider exclusion can be favored by evolution.

Theories of Ethnocentrism

Several theories have been proposed to explain the phenomenon of ethnocentrism. LeVine & Campbell (1972), whose work on the subject is a classic, listed the following: Realistic group conflict theory; reference group theory; sociopsychological theories (including group narcissism theory, projection theory, protest masculinity theory, and frustration-aggression-displacement theory); cognitive congruity theories; transfer theory; and reinforcement theory. The most relevant of these theories will be briefly discussed.

Realistic Group Conflict Theory
This theory assumes that group conflicts are rational in the sense that groups do have incompatible goals and are in competition for scarce resources. Such 'realistic' sources of group conflict are contrasted with the psychological theories that consider intergroup conflicts as displacements or projective expressions of problems that are essentially intragroup or intraindividual in origin.
"Real threat causes in-group solidarity" is the most recurrent explicit proposition of the theory. A parallel mechanism is the rejection of deviants and vengeance against renegades, apostates, revisionists, and heretics as a solidarity-promoting mechanism. Leaders may also seek out an enemy or create a fictitious one just to preserve or achieve in-group solidarity. This is certainly one of the most ubiquitous observations in the literature.

Group Narcissism
In Group Psychology and the Analysis of the Ego (1921), Freud regarded ethnocentrism as a form of narcissism at the group level. Later, in Civilization and Its Discontents (1930), he stated explicitly that the social function of group narcissism lay in its facilitation of the displacement of aggression from in-group to out-group.
The various human pseudospecies also exploit what Freud called the "narcissism of minor differences" to exaggerate their own distinctiveness and, by implication, their superiority.

Perhaps no concept has been more consistently applied to group stereotypes by psychoanalytic observers than that of projection, that is, the attribution to others of unacceptable impulses within one's self.
Pseudospeciation may be understood - at least in part - as an expression of one group's projection of its demonology and displacement of its self-generated aggression onto another. Undesirable characteristics will turn up attributed to an out-group (projection) which will then serve as a rationalization for violence against the out-group (aggression displacement) (Erikson, 1964).

Compensatory or Protest Masculinity
LeVine & Campbell (1972) speculate "that it is protest masculinity [a compulsive masculinity which is really a defense against feminine identification], with its heightened group narcissism, its hypersensitive, proud, prestige-conscious belligerence, that lies behind the ethnocentrism syndrome in its most extreme and irrational forms, not only in fighting gangs and feuding warriors but in the contemporary nationalistic leadership of competing states".

Social Identity Theory and Group Animosity

Social identity theory - which was largely developed after the appearance of LeVine & Campbell's classic opus - proposes that individuals engage in a process in which they place themselves and others in social categories. There are several important consequences of this social categorization process:
(1) Similarities between self and in-group members, and dissimilarities with out-group members are exaggerated (the accentuation effect).
(2) The stereotypic behavior and attitudes of the in-group are positively valued, while out-group behavior and attitudes are negatively valued. Individuals develop favorable attitudes toward in-group members and unfavorable attitudes toward out-group members
(3) The result of these categorization processes is group behavior which involves discrimination against the out-group; beliefs in the superiority of the in-group and inferiority of the out-group; and positive affective preference for the in-group and negative affect directed toward the out-group (MacDonald, 1992, 1996).
Tajfel (1970 et seq.), and many other social psychologists, provided experimental support for the hypothesis that an individual will discriminate against a member of an out-group even when (a) there is no conflict of interest; (b) there is no past history of intergroup hostility; and (c) the individual does not benefit personally from this behavior. Mere (random) categorization is sufficient to produce intergroup discrimination and prejudice (cf. also Rabbie, 1982, 1992; R. Brown, 1985; Hogg & Abrams, 1987, 1993; Tönnesmann, 1987; Vine, 1987; Abrams & Hogg, 1993; MacDonald, 1992, 1996; among many others).
Furthermore, people very easily adopt negative stereotypes about out-groups and these stereotypes possess a great deal of inertia (i.e., they are slow to change and are resistant to countervailing examples).
Social identity theorists propose that it is the need for high self-esteem which drives the entire process (MacDonald, 1992, 1996). Also Horowitz (1985) posits the quest for the affirmation of 'personal worth' as a central motive of human behavior: "self-esteem is in large measure a function of the esteem accorded to groups of which one is a member". Hence, "the sources of ethnic conflict reside, above all, in the struggle for relative group worth".
Anthropological evidence indicates the universality of the tendency to view one's own group as superior (e.g., Davie, 1929; Vine, 1987; Shaw & Wong, 1989; van der Dennen, 1995; MacDonald, 1996), and the empirical results of social identity research are highly compatible with an evolutionary basis for ethnocentric group behavior. A. Flohr (1994) similarly concludes her extensive review that there is a biological disposition toward ethnocentrism. Lopreato (1984), Irwin (1987, 1990), Shaw & Wong (1989), and Wuketits (1993) provide some compelling arguments why humans are genetically predisposed to ethnocentrism: in the EEA ethnocentrism and xenophobia enhanced individual reproductive success and survival. It can thus be considered to be a (bio)rational disposition.
In addition to the suggestion of universality, an evolutionary interpretation of these findings is supported by results indicating that these social identity processes also occur among 'advanced' animal species such as chimpanzees (e.g., Goodall, 1986).
Moreover, as MacDonald (1992, 1996) points out, the powerful affective component of social identity processes is very difficult to explain except as an aspect of the evolved machinery of the human mind.
Within the framework of social identity theory, there is clearly no requirement that the beliefs regarding the in-group or the out-group be true. Bigelow (1969) notes that "each group requires something intimate, unique to itself, around which its members can cohere. Irrational beliefs serve this purpose far better than rational ones; they are not only easier to produce, but also less likely to be confused with enemy beliefs. Irrational fantasies produce a continuous supply of 'group uniforms', promoting and maintaining internal cohesion within each group, and segregation between groups".

Dynamics of In-group/Out-group Differentiation

Many authors have suggested that the separation of ethnic, racial, or social groups fosters hostility by blocking off communication. Without interaction between people or groups, it is easy for autistic spirals of hostility to develop. Especially, Newcomb (1947) pointed out the vicious circle by which an individual or a group once ready for hostile responses gradually reduces the channels of communication with the potential enemy, thus preventing rectification of the early impression of hostility and redress by friendly actions. Hostile isolation or autistic hostility is likely to make hostile tension more enduring (which does not necessarily mean that contact reduces hostility and prejudice between individuals and groups).
Simmel (1904, 1955) and Coser (1956) proposed that conflict serves to establish and maintain the identity and boundary lines of societies and groups. According to the 'safety-valve theory' of conflict, conflict also serves as an outlet for the release of hostilities which, without it, would sunder the relation between the antagonists.
Sherif and his coworkers (Sherif, 1956 et seq.; Sherif & Sherif, 1953; 1966; Sherif et al., 1961) have been particularly interested in the experimental production and reduction of friction, conflict and negative stereotypes between groups. All the field experiments verify the hypothesis that conflict between two groups tends to produce an increase in solidarity within the groups. In the first experiment, the introduction of a common enemy (another competing group) was successful in reducing conflict between the original two groups. This set of studies substantiate the point that the external threat that increased internal cohesion must involve an achievable superordinate goal (Stein, 1976).
One of the few attempts to replicate the Sherif experiments was that of Diab (1970). This experiment had some frightening consequences for the subjects as well as for the researcher who had to be hospitalized for exhaustion after the experiment was abruptly terminated. He had been too successful in arousing intergroup hostility. The conflict got completely out of hand; some boys knifed each other and the police had to evacuate the camp to prevent further violence (Rabbie, 1982).
Some of the intricate dynamics of the process of in-group/out-group antagonism, escalating into downright 'warfare', may be grasped from the accounts of McNeil (1961, 1962), living with a group of 70 "aggressive, anti-social, anti-adult boys" in a therapeutic summer camp. At once, the boys began a pattern of militant probing of one another in their individual and group relations seeking to establish a basis for dominance and submission. The camp's aggressive pecking order was established through a number of interpersonal devices which resemble those used by primitive communities as well as civilized states to establish their position in the world: saber rattling, recounting past glories, the role call of allies, and deterrence by attack.

The Logic of Ethnocentrism: The Duality of the Human Mind

The particular logic of ethnocentrism, its Manichaean duality which dichotomizes the world into A and non-A, self and other, in-group and out-group, us and them, friend and foe, seems to spring from the cognitive capacity of Man to classify, categorize, differentiate, dichotomize and discriminate, but also his ability to generalize.
The human tendency to think in binary categories or oppositions has often been noted, ever since Boole in his Laws of Thought (1854) made a strong case for its inevitability. It is part of our phylogenetic substrate of basic problem-solving strategies and cognitive heuristics.
The world view of many peoples seems to be made up of a number of binary opposites or antinomies (self/other; order/chaos; safety/danger; friend/foe; peace/war; clean/dirty; human/nonhuman; good/bad; familiar/alien, etcetera), which, furthermore, tend to cluster together at the positive and negative poles, such that the self (and, by extension, the in-group) is good, clean, and associated with order and safety; while the other (and, by extension, the out-group) is alien and strange, and associated with chaos, danger, dirt, and potential violence.
Meyer (1987) pointed to the phenomenon that members of primitive groups frequently take their traditional enemy group as a kind of negative identity reference.
The human being has a powerful urge to dichotomize, E.O. Wilson (1978) states, and "We seem able to be fully comfortable only when the remainder of humanity can be labelled as members versus nonmembers, kin versus nonkin, friend versus foe".
Possibly ethnocentrism operates as a primordial psychological mechanism which brings about a distinction of 'us' and 'them', in-group and out-group, and it may be hypothesized that 'advanced' species like chimpanzees and humans have extra-strong needs for group boundaries, demarcations or delimitations, the strength of which must somehow be related to the species' affective systems.
Our way of thinking has evolved as a response to the practical problems of living and reproducing in the Environment of Evolutionary Adaptedness, and not to solve academic puzzles. We tend to think more in terms of categories or classes than in terms of individuals. Using these generalizations we form schemata. These schemata are extremely useful, but at the same time they enable us to form stereotypes. With regard to this regrettable side-product one could say with Anderson (1980): "Stereotyping reflects the dark side of schema abstraction".
All organisms have to rely to a considerable degree on extrapolations based on their experiences, i.e., they have to make inferential judgments, so to speak. As long as these are more likely than a random search to lead to correct judgments, thereby protecting the conditions of survival, they are functional (Flohr, 1987).
Riedl (1980, 1985) has pointed to the enormous role that pre-judgments play in the behavior of all living systems. As he puts it: "The algorithm of living systems is not founded on the apparent contradictions of our inductive logic, but on probability". In order to perceive and to evaluate, we have innate pre-judgments at our disposal, a whole system of phylogenetically acquired orientations that has been called 'ratiomorphic apparatus'.
Reification ('ideas-become-real'), also called 'hypostatization', refers to the human capacity to treat an abstraction as a real thing, substance or entity. It may even be anthropomorphized, taking on human or quasi-human form. Reification is critical to human action. It imposes familiarity and order on an otherwise chaotic environment (Peterson, 1981; Lumsden & Wilson, 1981, 1983). Examples are the anthropomorphized and personalized representations of the mother- or fatherland in nationalistic hymns, patriotic battle songs, and national anthems from all over the world. Such images are almost always employed as powerful mobilization devices in warfare.
The leader as the reification of the group is perhaps the most powerful form of symbolization. As Ike (1987) observes: "An individual person cannot identify himself with a large number of people; he needs a small group, a reference group, a peer group. Or he wants a symbol, a leader as stand-in for the larger mass of individuals with whom he cannot identify. The leader is the symbol, and the larger and stronger the number of individuals he represents, the better qualities are attributed to, or 'projected' on him".
Humans have a deep-rooted propensity to respond emotionally to symbolic representations of their in-group. These emotional qualities may include spontaneous joy, a sense of pride, and the security of belonging. The in-group becomes emotionally integrated into the individual's self-system or identity (Isaacs, 1975; Tönnesmann, 1987). In the expanded group context, emotions are typically aroused and reinforced through the language of kinship and the use of rituals, flags, anthems, drums, marches, and various kin-related heuristics (sacrifice for the Motherland) that have proven highly effective in promoting group solidarity (e.g., G.R. Johnson, 1986).
This strong emotional aspect is a rather neglected part of the dangers human groups constitute for each other, Elias (1987) observed. Human groups seem to take a strange delight in asserting their superiority over others, particularly if it has been attained by violent means. The feeling of group superiority appears to provide its members with an immense narcissistic gratification. People in power can usually count on a warm response of approval and often of affection and love from their compatriots whenever they praise or add to the glory of the social unit.
All these phenomena can be understood, in the last analysis, as pertaining to our finite time-and-energy budgets, and consequently our limited capacity to sympathize with, identify with, and be emotionally involved with more than a very limited number of conspecifics (Warnock, 1975; Ike, 1987). "Being a limited resource, affectivity in man favors interaction units where this resource may be invested in the most economical manner: it can be bestowed on a limited number of persons only" (Meyer, 1987). Hence the individual's limited niche in the nexus of cross-cutting human configurations. Human affectivity is of major importance in the establishment of social boundaries. Any social system requires boundary maintenance and mutual identification of actors (Meyer, 1987; Ike, 1987; a.o.).
The human sympathy group seems to be limited to about 11 individuals (Buys & Larson, 1979). These authors suppose that this magnitude possibly has co-antecedents in the human social-biological evolution, i.e., in the small hunting bands of our ancestors.
For most of our evolutionary history group identification was essential to the survival and well-being of the individual (Wallace, 1864; Darwin, 1871; Alexander, 1974 et seq.; Corning, 1983; Barash & Lipton, 1985; Dunbar, 1987; Flohr, 1987; Slurink, 1994; Caporael, 1996; a.o.). Thus we see that an important element in the psychological make up of human beings is a profound inclination to belong, to be part of a group, and the bigger and more powerful the group, the better. For our ancestors "security came in large part from the defense of the tribe against other tribes" (Barash & Lipton, 1985). Survival depended on the cooperative assistance of one's fellow group members.
Alexander (1974 et seq,), Slurink (1994) and Caporael (1996), among others, argued that during hominid/human evolution individuals better adapted to group-living (even to the point of hypersociality and obligate interdependence) would have been selectively favored.
At all times we had to rely on support by the group, and also on being accepted by the group. For this reason we had to adapt to the group; we had to adopt its modes of behavior and its value orientations. High respect for one's group more or less (psycho)logically implies devaluing out-groups. A tendency to form prejudices can thus be derived from our striving for group identity (Flohr, 1987).
Stereotypes and prejudices are, unmoralistically considered, heuristics or cognitive templates which work most of the time, and which prevent the stimulus overload of the cognitive system, and which provide some degree of self-esteem by creating a simple order out of chaos and uncertainty. "We love our prejudices, because they not only provide us with cognitive, but also with social stability" (Bergler, 1976).
Also Van den Berghe (1997) reasoned that, far from being inflexible, irrational, resistant to experience, and situationally insensitive, stereotypes are, for most people most of the time, low-cost statistical guides to action in situations where transient encounters between strangers make better information costly, unavailable or risky.
Ethnic and racial prejudices are not necessarily based on personal experiences and they do not necessarily have to reflect private interests. Instead they can be acquired early in life along with other values and attitudes that are normative in their social environment.
Anne Flohr (1994) lists the following cognitive mechanisms: selective perception and perceptual distortions (double standard in judging the same behavior of members of ingroup and outgroup), avoidance of dissonant information, 'boomerang effect' (Jervis), 'confirmation bias' (Peterson), 'availability heuristic', 'halo effect', and 'evoked sets'.

Evolutionary Theories of Ethnocentrism

Ethnocentrism is a major explanans in contemporary theories of primitive warfare. The founding father of modern sociobiology, E.O. Wilson (1978) regards it as a culturally hypertrophied biological predisposition:

The practice of war is a straightforward example of a hypertrophied biological predisposition. Primitive men cleaved their universe into friends and enemies and responded with quick, deep emotion to even the mildest threats emanating from outside the arbitrary boundary...
The force behind most warlike policies is ethnocentrism, the irrationally exaggerated allegiance of individuals to their kin and fellow tribesmen.

Also Meyer (1977 et seq.) regards ethnocentrism and xenophobia as cultural hypertrophies. He argues that the extreme ethnocentrism of primitive peoples sets preconditions for violent interaction, while specific conditions serve as triggers. Meyer suggests that the basic motivation in violent encounters between members of distinct groups is not 'aggression' impelled by some sort of drive, instinct, or appetite, but 'fear'. Fear generated by the position of the cultural 'we-group' in a threatening universe made up of 'they-groups', endangering the social cosmos by their very existence.

Kin Selection and Inclusive Fitness
Evolutionary and sociobiological explanations of ethnocentrism and xenophobia are for the most part rooted in kin selection, inclusive fitness, and altruism theories. Inclusive fitness, as Alexander (1979) explains, is a simple idea. As social organisms we tend to lead our lives embedded in networks of near and distant kin. The concept of inclusive fitness simply tells us that not merely our offspring but any genetic relative socially available to us is a potential avenue of genetic reproduction. Altruism toward relatives is of course not really altruism at all, but rather the tendency of individuals to maximize the reproductive success of their genes via their relatives, that is, via the other bodies in which copies of these genes reside.
Alexander & Borgia (1978) argued that nepotism to nondescendants and distant descendant relatives is an extension of (evolutionarily) earlier altruism in the form of parental care. Alexander (1979) argued that reciprocity (or 'selfish cooperation' as Corning [1983] called it) is in turn largely derived from nepotism. Vanhanen (1992) considers tribalism, casteism, nationalism, etc. as forms of nepotism adapted to large societies).
In the small bands in which humans are generally presumed to have lived during most of their evolutionary history, virtually all social interactions were among relatives. The same is probably true for contemporary hunter-gatherer societies.'Generalized reciprocity' involves mostly one-way flows of benefits because it is largely nepotism (the return is genetic), and 'negative reciprocity' involves one-way flows because it consists of one-time interactions accompanied by a great deal of social cheating and/or exploitation and coercion.
'Balanced reciprocity', on the other hand, tends to occur between distant relatives or nonrelatives that are likely to interact repeatedly, and therefore involves balanced flows of benefits (see also Masters, 1964; Service, 1966; and Shaw & Wong, 1989).
The moral gradient and the vector of violence and dehumanization running through these concentric circles (see diagram) was already clearly seen and eloquently formulated by Marett (1933): "[T]here stand out in sharp contrast to each other three spheres of conduct, to which entirely separate commandments apply as follows: to the first, Thou shalt commit no murder; to the second, Thou shalt compound with thy neighbor on the principle that a life for a life is fair give-and-take; and to the third, Thou shalt utterly destroy the destroyer".
In discussing the absence of war in some Inuit tribes, Irwin (1987) predicted (in contrast to Hamilton, 1975) that social behavior can be polarized at all population boundaries where there is some variation in the coefficient of relatedness between adjacent demes. In other words, Irwin said, rivalry between closely related human populations is as predictable a phenomenon as sibling rivalry. If the humans in these populations stopped making war then something must have happened to the coefficient of relatedness, or the cost/benefit ratio, or both.

Cultural Badges and the Proximate Mechanisms of Kin Recognition
What features will be chosen as ethnic markers or badges? There are many possibilities, tending to fall into three main categories of traits (Van den Berghe, 1981):
First, one can pick a genetically transmitted phenotype, such as skin pigmentation, stature, hair texture, facial features or some such 'racial' characteristic.
Second, one can rely on a man-made ethnic uniform. Members of one group are identified by bodily mutilations and/or adornments carried as visible badges of group belonging. These markers range from clothing and headgear to body painting, tattooing, circumcision, tooth filing and sundry mutilations of the lips, nose and earlobes.
Third, the test can be behavioral. Ethnicity is determined by speech, demeanour, manners, rituals, ceremonies, etiquette, esoteric lore or some other proof of competence in a behavioral repertoire characteristic of the group. Language is the supreme test of ethnicity (e.g., the shibboleth), because it is almost absolutely 'fake-proof'. Many, including non-ethnic groups, use particular attitudes or idiosyncrasies as litmus tests of group membership.
Some criteria seem to have more staying power than others, and the ones with high heritability appear to have an edge (Van den Berghe, 1981, 1989, 1992).
Shaw & Wong (1989) consider as recognition markers, taking on potent heuristic and emotive value in demarcating in-group/out-group boundaries, to include language, religion, phenotype, homeland, and myth of common descent.
To deal with the problem of in-group membership recognition, natural selection has repeatedly evolved a proximate mechanism known as badging. Badges can be learned and may be one of the simplest, most rudimentary forms of culture presently known (e.g., bird song dialects).
Irwin (1987) suggested that many aspects of culture which vary dramatically from tribe to tribe could be understood as learned and culturally transmitted ethnocentric expressions of a genetic predisposition to group bonding and badging, rather than as adaptations of tribe to tribe differences in immediate ecology. Differences in dialect, dress, art, symbol, ritual, scarification, tattoos and/or body paint symptomatic of group membership could fall into this class of culture traits. Most cultural differences may be assumed to be of the badging variety.
Association/familiarity is a very likely candidate for kin recognition among humans. But it seems probable that phenotypic matching is another and supplementary mechanism (Alexander, 1979; Michod, 1982).
From a sociobiological perspective, as Tönnesmann (1987) points out, one should not expect a human being to be willing to cooperate indiscriminately with any other conspecific, but to apply criteria such as similarity in physical appearance in order to assess the possibility of a genetic relationship. Thus one could say with Barkow (1980) "that we should most readily learn distrust and hostility towards those who least resemble us, and towards those with whom we have no personal relationship, that is, strangers" (Barkow, 1980). In fact, similarity seems to be related to empathic responses, and, more generally, liking between individuals is increased when they perceive each other as similar (e.g., Turner, 1982).
Rushton (1986, 1988) and Rushton, Russell & Wells (1984) developed 'genetic similarity theory': "If a gene can better ensure its own survival by acting so as to bring about the reproduction of family members with whom it shares copies, then it can also do so by bringing about the reproduction of any organism in which copies can be found... It can be expected that two individuals within an ethnic group will, on average, be more similar to each other genetically than two individuals from different ethnic groups" (Rushton, 1986; see also Eibl-Eibesfeldt, 1989). Kenrick (1989), on the other hand, argued that "people are not so much attracted to similar others, as they are repulsed by those who are not similar". The consequence, however, a biologically based disposition toward ethnocentrism, would be the same (A. Flohr, 1994).
Ethnic markers, such as skin color, clothing, or behavioral peculiarities, could be used for the purpose of making an ethnic group appear to be a group of genetically related individuals. Altruistic acts on behalf of non-kin can be elicited by taking advantage of the cues produced by evolution for kin recognition. According to G.R. Johnson (1986), patriotism in contemporary large-scale societies is a brand of manipulated altruism. Large-scale human societies have evolved processes of socialization which exploit the cues by which altruism originally came to be elicited in the course of several million years of hominid evolution.

Kin Selection, Nepotism and the Genetic Seeds of Warfare
In The Ethnic Phenomenon, Van den Berghe (1981) formulated the first theory of ethnocentrism as extended kin selection. Van den Berghe's basic argument is quite simple: ethnic sentiments are extensions of kinship sentiments. Ethnocentrism is thus an extended form of nepotism - the propensity to favor kin over nonkin.
Ethnicity is a matter of degree of relatedness. People typically form both alliances and cleavages, and grade the violence and destructiveness they inflict on each other on the basis of their real or perceived degree of relatedness. That is, both cooperation (nepotism and reciprocity) and conflict (coercion and exploitation; negative reciprocity) in and between human societies follow a calculus of inclusive fitness.
An ethnic group (or ethny) can be represented as a cluster of overlapping, ego-centered, concentric kin circles, encompassed within an ethnic boundary. The ethnic boundary is seldom completely closed. More typically, there is some migration, principally of women, among groups.
Ethnicity is defined, in the last analysis, by common descent. Ethnic boundaries are created socially by preferential endogamy and physically by territoriality. The prototypical ethny is thus a descent group bounded socially by inbreeding and spatially by territory.
We have evolved, Van den Berghe argues, the kind of brain to deal with small-scale, Gemeinschaft-type groups, the prototype of which is the ethny, the 'we-group', the 'in-group' of intimates who think of each other as an extended family. Ethnicity can be manipulated but not manufactured.
Furthermore, he argues, ethnocentrism does not automatically and invariably imply xenophobia. Being for one's own group does not, of necessity, imply being against all other groups. Unqualified exclusion of vast categories of potential partners in reciprocal exchanges is not the best strategy.

Shaw & Wong (1989) present an elaborate theory of kin selection, ethnocentrism, and the evolution of human warfare. They propose that inclusive fitness considerations have combined with competition over scarce resources, intergroup conflict, and weapon development, to
(1) reinforce humanity's propensity to band together in groups of genetically related individuals;
(2) predispose group members to act in concert for their own well-being; and
(3) promote xenophobia, fear, and antagonism among genetically related individuals towards strangers.
Shaw & Wong interpret these responses as 'emerging' or reinforcing proximate causes which shaped the structure of social behavior in hunter/gatherer groups for 99 percent of humanity's existence. Their model rests on three premises: that individuals have evolved not only to be egoistic, but to be nepotistically altruistic; that individuals in nucleus ethnic groups, are predisposed to mobilize for resource competition in ways that will enhance inclusive fitness and reproductive potential; and that intergroup conflict/warfare has been positively functional in humanity's evolution.
The considerations raised above interact to make mobilization for conflict or warfare a more viable, cohesive strategy if pursued among related kin. From an evolutionary perspective, these considerations are the bedrock upon which Shaw & Wong link ethnic mobilization and the seeds of warfare.
Since failure to maintain a balance-of-power (Alexander, 1979, 1987) could have resulted in extinction, groups and their expansion figure as forces of selection in Shaw & Wong's theory. Motivated by resource competition, conflict, and warfare, struggles to maintain balances of power gave rise to more complex societal units (e.g., chiefdoms, states) which continued the legacy of intergroup warfare. Groups as forces of selection must have reinforced suspicion and intolerance of out-group members as well as war proneness during a long period of humanity's past.
If resources are defendable, and if conflict is inevitable, as McEachron & Baer (1982) have explained, it makes better evolutionary sense for groups to compete to resolve ownership of the resources as groups rather than being submitted to both the internal conflict and decreased inclusive fitness that would accompany a merger.
As Hamilton (1975) observed, to raise mean fitness in hunter-gatherer groups either new territory or outside mates had somehow to be obtained. Capture of out-group females through successful warfare, Shaw & Wong continue, serves three functions: (1) it reduces inbreeding depression by increasing the number of available partners for reproduction; (2) it increases variation in the warring group's genetic stock; and (3) it contributes to group size. The latter consideration would have been especially important in environments where groups were effective forces of selection. The practice of taking females for loot would undoubtedly have set rival groups on edge and reinforced xenophobia and out-group enmity in the process.
In the evolutionary long run, larger groups would have displaced smaller groups and their members would thus have staked out a larger share of humanity's gene pool. This implies that behavioral predispositions that facilitated group expansion would have been retained and incorporated into the more permanent repertoire of individual and group behavior (see also Bigelow, 1969, 1972).
A perspective very similar to Van den Berghe's and Shaw & Wong's theories has been presented by Vanhanen (1991, 1992) and A. Flohr (1994).

Van den Berghe (1997) posed the question: "ethnocentrism: in our genes or in our memes?". It may now be understood that the answer must inevitably be: in both.

This paper is based on the chapter "Of badges, bonds and boundaries: ethnocentrism, xenophobia, and war" in: J.M.G. van der Dennen (1995) The Origin of War. Groningen: Origin Press.
It was published in: K. Thienpont & R, Cliquet (Eds.) In-group/Out-group Behaviour in Modern Societies: An Evolutionary Perspective Brussels: NIDI GBGS Publications, 1999, pp. 37-74.


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