Inequality, Culture, and Violence: Assessing the Legacy of Johan Galtung

PAPER OF THE WEEK, 6 Jul 2026

Solveig Hillesund and Gudrun Østby | Journal of Global Security Studies - TRANSCEND Media Service

Abstract

Introduction

Johan Galtung (1930–2024) is widely regarded as a foundational figure in the early development of peace research, having written extensively on a wide range of topics, such as structural violence, concepts of peace, international news dissemination, and imperialism. His theoretical contributions, particularly his concepts of direct, structural, and cultural violence, significantly shaped early scholarly debates on equality, justice, and peace within the field.

In his editorial for the inaugural issue of Journal of Peace Research, Galtung (1964) formulated the concepts of “negative peace” and “positive peace” as the dual goals of peace research. Negative peace, he referred to as the mere absence of war and violence. In contrast, positive peace was described as “the integration of human society” (Galtung 1964, 2). He later redefined positive peace as the negation of what he labeled “structural violence,” a form of violence distinct from “direct violence” (perpetrated by individuals or groups), as it originates from the very structure of a social system (Galtung 1969). This was controversial. His contemporary critics countered that structural violence seemed to cover everything that Galtung did not like and labeled his ideas as “a socialist theory of peace within a neo-Marxist theory of exploitation” (Rummel 1981, 50, 83).

As acknowledged by Boulding, one of Galtung’s more friendly critics, Galtung’s discussion of structural violence served to draw attention to the problem of poverty and deprivation, which should be a high priority for research and action. However, Boulding (1977, 83) found “structural violence” to be a misleading metaphor, alluding to a flawed model of reality. By labeling poverty, deprivation, and ill health as violence, suggesting inequality is “like” a thug beating someone up, or a conqueror stealing someone’s land, Galtung could be accused of diverting attention away from the very real problem of structures that lead to violence, which, according to Boulding, are created and sustained by very different processes than poverty.¹

Regardless of what one thinks about Galtung’s labeling of inequalities as violence, central elements in his thinking appear to have been picked up and developed further by other researchers, though they are often not attributed to him. Subsequent research on inequality and conflict seldom acknowledges Galtung as a direct source of inspiration. Central scholars such as Ted Gurr, Donald Horowitz, and Frances Stewart rarely cite Galtung in their key works on group-based inequality and political violence (e.g., Horowitz 1985; Gurr 1993; Stewart 2002),² and some quick searches on Google Scholar suggest that the same is often true for more contemporary contributions (e.g., Murshed and Gates 2005; Østby 2008a; Cederman, Weidmann, and Gleditsch 2011, Cederman, Gleditsch, and Buhaug 2013; Bartusevičius and Gleditsch 2019; Hillesund 2019).

Nevertheless, there are arguably similarities between Galtung’s early theorizing and contemporary research on inequality and conflict. Our current review essay is motivated by these parallels and pursues a dual aim: first, we trace the echoes of Galtung’s ideas in current theoretical frameworks concerning inequality and conflict, particularly in research that addresses “horizontal inequalities” (HIs, i.e., systematic inequalities between identity groups) and political violence within states. Second, we assess whether Galtung’s key propositions stand up to empirical scrutiny by reviewing findings from contemporary econometric studies on peace and conflict. Our primary focus is on the quantitative empirical literature assessing the link between HIs and political violence.

The article is structured as follows. First, we summarize and discuss some of Galtung’s central concepts and theorization relating to inequality, conflict, and culture, trying to identify some general, testable propositions. Second, we review contemporary research on inequalities and intrastate violence, with the dual purpose of tracing Galtung’s ideas in contemporary theories and assessing the empirical validity of his causal propositions in existing studies. We conclude with a brief discussion on the potential usefulness and challenges of operationalizing Galtung’s ideas on inequality and conflict in contemporary peace and conflict research. Although the practical implementation and empirical testing of Galtung’s broad concepts remain challenging and perhaps not always fruitful, his early work offers some key insights that seem to have influenced later scholarship on inequality and conflict.

Galtung’s Concepts and Theory: Inequality, Culture, and Violence

Four concepts are crucial for understanding Galtung’s thinking on equality, justice, and peace. Three of them he labeled as types of violence—that is, direct (sometimes called personal), structural (sometimes called indirect),³ and cultural violence. In theorizing about the relationship between inequalities (structural violence) and (direct) violence, Galtung introduced the concept of rank disequilibrium.

Central Concepts

In his seminal article “Violence, Peace, and Peace Research,” Galtung (1969) defined direct violence as all violence that hits human beings as a direct result of the actions of others. That is, the violence is committed by identifiable people (subjects) (Galtung 1969, 170). Beyond this conceptual core, his definition of the concept was very broad, especially for the 1960s context in which it was introduced. Galtung went beyond physical, intentional, and manifest violence to discuss violence in its more psychological, unintentional, and latent forms (Galtung 1969, 167–74). His examples ranged from killing and maiming, sieges, sanctions, and other denials of basic needs, like food and water, movement, and autonomy, to threats of violence and the destruction of things. Compared to the other forms, direct violence is the most visible, and the one that fluctuates most over time.

Structural violence is the term Galtung used for systematic inequalities built into the social structure, in the form of unequal power and life chances (1969, 170–1). That is, situations where socioeconomic resources (such as income, education, health services) and/or the power to decide over such resources are distributed unevenly between individuals, groups, regions, or countries. While acknowledging that such inequalities can be difficult to trace back to specific perpetrators, Galtung argued that “if people are starving when it is objectively avoidable, then violence is committed, regardless of whether there is a clear subject-action-object relation” (Galtung 1969, 171). He used the structural violence concept to argue for an expanded definition of peace: positive peace, defined as the absence of structural (not just direct) violence.

While direct and structural forms of violence are related phenomena, they are logically and empirically distinct: both can exist independently of the other, and neither presupposes a previous or latent presence of the other (Galtung 1969). Structural violence is more stable, but also less visible, than direct violence. In fact, people can be manipulated not to see it at all. It does sometimes take the form of bodily harm, when the underdogs in a society are extremely deprived, but more often its effects are psychological (Galtung 1969, 177).

Galtung’s idea of structural violence is rooted in unequal exchange: some people (groups) get more out of their interactions in the social structure than others. Galtung referred to them as topdogs and underdogs, respectively (Galtung 1990, 293). He described the social structure as consisting of a set of systems (or dimensions) of interaction, in which individuals and groups are ranked. Structural inequality (violence) is most stable when there is rank equilibrium. That is, when people and groups are similarly ranked across dimensions (Galtung 1969, 176–7), for example, if their rankings are consistently high (or consistently low) across political status, income, education, and other salient realms of society. The archetypical examples are the traditional Indian caste system and feudal slave societies (Galtung 1964).

Another of Galtung’s concepts with clear relevance to the link between inequality and conflict is cultural violence. This concept refers to “those aspects of culture, the symbolic sphere of our existence [. . .] that can be used to justify or legitimize direct or structural violence” Galtung 1990, 291). High-visibility examples include flags, anthems, military parades, portraits of the leader, inflammatory speeches, and posters. But cultural violence exists in subtle as well as overt forms, across many different cultural domains: religion, ideology, languages, art, and formal and empirical science. In the next section, we discuss Galtung’s thinking on how elements of culture can serve to legitimize inequality and violence, as well as other ways in which he argued that the three forms of violence—direct, structural, and cultural—influence each other.

Causal Arguments

In Galtung’s description, the three forms of violence (direct, structural, and cultural) influence each other in various complex ways. He argued that previous theories of aggression were over-simplified and nonstructural; that they did not take the social context sufficiently into consideration (Galtung 1964). In his structural theory of aggression, Galtung combined the idea of frustration with the idea of perceiving aggression as a possible way out of the frustrating situation—and here, one’s position in the social structure is crucial.

Galtung identified three types of systems, systems of individuals, of groups, and of nations, and claimed that a stratification within and between these systems is an inevitable, universal phenomenon. He assumed that there will be a division of labor between the elements in each system, that the elements will tend to be ranked according to certain criteria, and that the relative position of the elements according to these criteria will have a certain stability. Based on these assumptions, he deduced a hypothesis about when and where in the social structures aggression is likely to arise—the hypothesis of rank disequilibrium. Briefly, the hypothesis is that a perception of rank disequilibrium arises as a result of a discrepancy between how one perceives oneself and the way one is treated by the others in the system. A position in rank disequilibrium will be perceived as frustrating and can result in aggressive behavior.

For the sake of simplicity, Galtung deals with rank in terms of two positions only—high or low, or “topdog” (T) and “underdog” (U), as he calls them. Thus, if we rank individuals (or groups) on three dimensions of inequality (for instance income, occupation, and education), they may have equilibrated positions either at the top of the system (TTT), or at the bottom (UUU). Galtung’s hypothesis is that aggression is most likely to arise in social positions in rank disequilibrium (e.g., UUT).

In short, when “underdog” groups (or individuals, nations) rank low on most dimensions but higher on at least one, they may experience greater relative—though not absolute—deprivation than “complete underdogs,” as their higher rank raises the reference point for comparison. Crucially, their relative advantage also provides access to additional resources—such as money, skills, or cultural capital—which can facilitate mobilization (Galtung 1964).

In his foundational work on structural violence, Galtung argued that structural violence—manifested through inequalities—impedes the formation of critical consciousness by ensuring that the underdogs have only a partial view of what is going on (segmentation). It also obstructs their ability to organize (for voting, bargaining, striking, etc.), by keeping them excluded (marginalization) and isolated from one another (fragmentation) (Galtung 1990, 293). This notion may seem at odds with the idea that inequalities should ever lead to violence, at least not to violence initiated by the underdogs. However, in light of the rank disequilibrium hypothesis, the two lines of argument can be reconciled: if inequalities prevent consciousness formation primarily among the complete underdogs, this would help explain why rank equilibria are less likely to spur violence.

When Galtung (1990) later introduced the concept of “cultural violence,” he advanced broader and more encompassing causal claims. He encouraged the reader to picture his three forms of violence as a triangle (direct, structural, and cultural violence at its corners) claiming that violence can start in either corner, run in either direction, and result in vicious cycles of violence. This conceptualization allows for numerous causal paths and cycles, most of which were not spelled out or exemplified by Galtung himself. He did not attempt to determine whether any of the paths are (logically or empirically) more important, stronger, or more common than others.

However, Galtung (1990) devoted particular attention to one causal sequence, suggesting he considered it to be particularly central: the path from cultural violence to structural violence and on to direct violence. He described the three as “strata of violence”: a slow-moving (almost static) undercurrent of cultural violence seeps up into a process of ebbing and flowing structural violence, which nurtures bouts and peaks of direct violence at the surface. Only the latter are visible to the naked eye (or to the empiricist). In essence, cultural violence feeds structural violence, which contributes to direct violence.

How did Galtung justify this causal sequence? He discussed in some detail how cultural violence works. That is, how elements of culture have been used to legitimize structural and direct violence (Galtung 1990). In his analysis, cultural violence in religion and ideology has a central tenet in common: that some people are “chosen,” whether by God or otherwise (Galtung 1990). This forms the basis for various distinctions between “self” and “other” (“us” and “them”), which can be used to justify both direct and structural forms of violence against the “other.” Galtung identified several sources for such distinctions that have been common in the West. These include religion; nationalism and the idea that certain nations are carriers of civilization; the idea that white people (men) are more intelligent and logical than others; and, perhaps more subtle than these ascribed distinctions, the idea that modern societies are meritocracies, and therefore the people at the top are entitled to their privileges (Galtung 1990, 296–9). When several such ideas and ideologies come together, for example, in nation-states with a theologically based chosen people complex, the stage is set for disaster, according to Galtung. He cites examples such as Israel, South African Apartheid, and Nazi Germany to illustrate this point, but also the United States and France (Galtung 1990, 299).

Turning to other causal paths, Galtung’s article on cultural violence (1990) briefly argued that both direct and structural violence—individually or together—can contribute to cultural violence. In this view, the topdogs tend to seek post-hoc justification for atrocities they have already committed and unequal structures that already exist (such as the practice of slavery and the legacy of structural inequalities in the United States). The remaining causal paths and cycles were left largely unexplored.

Propositions and Operationalization

Our inquiry seeks to explore theoretical discussions and empirical evidence of some of the most foundational assumptions—essentially propositions—that can be derived from Galtung’s work. To structure this discussion, this section outlines some key testable implications emerging from the above discussion and identifies the concepts in contemporary research that we think best correspond to each of Galtung’s original formulations.

Testable Implications

One of the primary implications of Galtung’s causal discussions is that (1) inequalities foster violent conflict (inequality–violence proposition). At first glance, this seems at odds with the idea that structural inequalities impede consciousness formation and organization, a central argument in Galtung’s discussion of structural violence. However, various parts of Galtung’s scholarship suggest nuances that could resolve the apparent contradiction.

Galtung’s work on cultural violence and rank disequilibria, respectively, implies that the inequality–violence relationship should be most pronounced under conditions where (1.1) it is legitimized by elements of culture (culture proposition); and/or where (1.2) groups or individuals are ranked differently along different dimensions of inequality (rank disequilibrium proposition). With regard to the latter, when groups or individuals are ranked consistently on the bottom along all salient dimensions, consciousness formation and organization are almost impossible, whereas for those ranked higher on at least one dimension, their perspectives (perceived relative deprivation) and resources differ in ways that facilitate mobilization. The disequilibrium proposition comes out of Galung’s early work, whereas the culture proposition originates from his later work on cultural violence and how culture can legitimize inequalities and violence.

A final, more general, implication of Galtung’s discussion is that (2) in the inequality–violence nexus, causality runs in all directions, including vicious cycles (reciprocal causality proposition).

It is not an easy task to determine where nonviolent conflict mobilization fits in this causal complex. Nonviolent forms of mobilization, such as strikes and protests, are clearly distinct from the inaction that comes with suppressed consciousness formation and organization. Neither do they fit squarely within Galtung’s definitions of personal violence (or aggression). Since it is not clear whether Galtung’s work implies that structural inequalities cause nonviolent (in addition to violent) mobilization, we refrain from formulating an inequality–nonviolent mobilization proposition. However, we return to this question briefly in the discussion section.

Analytical Approach and Scope: Operationalizing Galtung’s Concepts

To trace Galtung’s legacy through the comprehensive literature on inequalities and violence that has emerged since the 1970s, we need to unpack his violence concepts. Since the concepts are very broad, conflict researchers have not (to our knowledge) tried to quantify structural or cultural violence as such. Furthermore, most studies of what Galtung labels direct violence focus on one or a few sub-categories of such violence. More attention has been paid to its most observable manifestations, and less to its psychological, latent, and unintentional forms.

In Table 1, we map Galtung’s concepts onto relevant concepts in contemporary research on inequalities and violence. Given the broad scope of his three forms of violence, it is beyond the reach of a single paper to review research on all the phenomena these concepts encompass. Therefore, we narrow our focus in two key ways: first, in operationalizing direct violence, we concentrate on within-state violence with political aims, rather than purely criminal intent, though we briefly address nonviolent forms of conflict in the concluding discussion. Second, we focus on inequalities between individuals and groups—commonly referred to as vertical and horizontal inequalities, respectively—while excluding inequalities between states or regions.⁴

The question of how to measure inequality has attracted growing attention in recent years. In the area of socioeconomic inequality between individuals (VI), pioneering work by scholars such as Atkinson (2015) and Piketty (2014) has significantly deepened our understanding of distinctions between income and wealth inequality while also advancing debates around absolute versus relative measures and the choice of inequality metrics (see, e.g., Bigsten 2024). In our review, we focus on inequalities between individuals (VI) and groups (HI), but impose no restrictions on the type of resource examined—whether income, wealth, land, education, public goods, or political influence—nor on the methods used to calculate inequality between individuals or groups (e.g. Gini coefficients, top/bottom income shares, absolute or relative measures).⁵

Assessing Galtung’s Propositions: A Review of Contemporary Research and Evidence

In this section, we outline Galtung’s legacy in contemporary peace and conflict research. We trace the echoes of his ideas in contemporary theories and review empirical findings from econometric studies to assess whether his key propositions, as identified above, stand up to empirical scrutiny. Our discussion is structured around the four propositions we introduced earlier: first, that (1) inequality fosters violence (inequality–violence proposition), but primarily (1.1) when it is supported by elements of culture (culture proposition) and/or (1.2) when groups or individuals are ranked higher on at least one dimension (rank disequilibrium proposition). Second, (2) that there is reverse and reciprocal causality involved (reciprocal causality proposition).

Not all Inequalities Foster War: Mixed Evidence on Vertical Inequalities and Violence

Since the 1970s, most studies on economic inequality and conflict have been rooted in Gurr’s (1970) relative deprivation theory, which posits that absolute poverty often leads to apathy and inactivity, whereas perceived inequality—where individuals compare themselves to better-off peers within the same society—can spark radical action and even violence.⁶ While it remains unclear how much Gurr was influenced by Galtung (or vice versa), they do share certain intellectual foundations, often drawing on similar sources for inspiration. For instance, both reference Davies (1962), who synthesized the ideas of Marx and de Tocqueville.

In Why Men Rebel (1970), Gurr does reference Galtung’s work on rank disequilibrium, which he interprets as a form of relative deprivation. Moreover, Galtung’s concept of structural violence and Gurr’s theorization on the conflict potential of relative deprivation exhibit notable conceptual parallels. If one focuses on direct (physical) violence, both Gurr and Galtung ultimately propose a similar expectation: economic inequality within a society fosters conflict.

Early empirical studies on inequality and conflict focused on vertical inequality—that is, inequality between individuals—of the economic kind. They reported very conflicting results. In short, the empirical literature from the mid-60s and onwards included examples of all possible relationships between economic inequality and political conflict: positive, negative, convex (inverted U-shaped), concave (U-shaped), or null (see, e.g., Russett 1964; Parvin 1973; Nagel 1974; Sigelman and Simpson 1977; Weede 1981; Muller and Seligson 1987).⁷

With a plethora of inconsistent findings in the literature, the inequality–conflict riddle remained unsolved by the late 1980s. In the mid-1990s, World Bank researchers Deininger and Squire (1996) presented a new dataset on income inequality, which was later expanded into the World Income Inequality Database (UNU/WIDER and UNDP 2000), a great improvement in terms of quality and spatio-temporal coverage of inequality data.

Subsequently, in virtually all cross-country regressions of civil war, economic inequality was dismissed as statistically insignificant. Seminal studies included Collier and Hoeffler (2004) and Fearon and Laitin (2003). Neiher cites Galtung. In any case, their empirical findings contradicted Galtung’s ideas. They largely dismissed the conflict potential of inequality and other grievances, focusing instead on the resources and opportunity structures that make violent mobilization more feasible; like low opportunity costs and weak state capacity (see Østby 2013 for an overview).

Recent studies of vertical inequality and violence have brought back broader definitions of political violence (i.e., moved beyond civil war). Using improved data and methods, they show that while socioeconomic inequality between individuals does not affect the risk of civil war,⁸ it is associated with various other forms of political violence and instability (Alesina and Perotti 1996; Roe and Siegel 2011), including guerilla warfare and revolutionary episodes (Boix 2008; Houle 2019), demonstrations and riots, strikes, and assassinations (Houle 2019). Interestingly, most of the associations between income inequality and violence disappear when controlling for social mobility (Houle 2019). Thus, they seem to be driven by situations where inequalities and low mobility go hand in hand. We return to the implications of this finding in the section on rank disequilibrium.

In sum, there appears to be little evidence that vertical socioeconomic inequalities cause civil war, and their link to other violence depends on the degree of social mobility.

What about vertical inequalities along the political dimension? While the term “political vertical inequality” is not in common use, the phenomenon it refers to—unequal distribution of political access and influence between individual citizens—is much studied in political science and peace and conflict studies, usually under labels such as autocracy and political and civil rights violations. According to the theories of Galtung and other scholars in the late 1900s, democracies and countries that respect civil rights should be the least violence-prone, since they will harbor fewer grievances overall (see, e.g., Fearon and Laitin 2003 for a summary and critique of this argument).

Similar to the early studies of socioeconomic inequality, empirical studies of political inequality between individuals, typically measured as regime type,⁹ show no straightforward association with armed conflict. Full autocracies are not necessarily the most prone to civil war, nor are liberal democracies consistently the least likely to experience such conflict (e.g., Cederman et al. 2013, 146–56; Fearon and Laitin 2003). Instead, the regimes most susceptible to conflict tend to lie between these two extremes—variously referred to as hybrid regimes, anocracies, or semi-democracies (Hegre 2014). One might argue that the latter resonates with Galtung’s theory of rank disequilibrium. That is, in situations where many people are underdogs across various dimensions (socioeconomic status, etc.), granting them some political access creates a form of rank disequilibrium, with corresponding potential for conflict. We discuss the rank disequilibrium proposition in more detail in the next section. However, it is noteworthy that the mentioned studies do not cite Galtung.

Accounting for Culture: HIs, Civil War, and Political Violence

The statistical rejection of the inequality–conflict nexus at the turn of the century was not universally accepted, and subsequent research suggests that it was indeed premature. In qualitative conflict research, inequalities continued to feature prominently, especially in the form of inequalities between ethnic identity groups. This identity dimension of inequality, poorly captured in studies measuring inequality with income GINI coefficients, was picked up by Stewart (e.g., 2000, 2002, 2008) and her collaborators as an alternative avenue for capturing the inequality–conflict link. Their work served to shift attention to the role of HIs, defined as “inequalities in economic, social, or political dimensions or cultural status between culturally defined groups” (Stewart 2009, 3), as a potential cause of political violence, also in the econometric literature.

It is in this literature on HIs that we see the clearest traces of Galtung’s thinking on inequality and conflict, though they are rarely acknowledged as such.¹⁰ Inequalities between groups, an important sub-category of Galtung’s structural violence concept, clearly parallel the HIs concept. Moreover, early conceptual work on HIs emphasized the multidimensionality of the concept, which resonates with Galtung’s thinking. Like structural violence, HIs have social, economic, and political dimensions (Stewart 2002).

Some of the causal mechanisms that contemporary scholars typically evoke to link HIs to violence bear a strong resemblance to Galtung’s work on cultural violence. HI researchers typically argue that for objective HIs to translate into group grievances (which can subsequently fuel violence), the distinction between “us” and “them” is key. When group elites or nascent movement entrepreneurs seek to harness collective motives and emotions to facilitate collective action, they must appeal to pre-existing aspects of groups’ history and culture. Without such connections, their narratives are unlikely to resonate with the people they aim to mobilize. In this process, the ideology of nationalism and the associated principle of self-determination are often evoked to underline the deep injustice of excluding entire ethnic groups from political power (Cederman et al. 2013).

A large body of econometric research from the last two decades confirms that HIs are associated with the onset of civil war and other forms of political violence. It is in this body of research that Galtung’s ideas about causal links between the different forms of violence find the most consistent empirical support.

Cultural narratives and experiences of grievance are difficult to evaluate empirically. Hence, it is not surprising that most of the empirical (econometric) literature on HIs and conflict focuses on more readily observable associations on the country, region, and group level.

By now, there is a comprehensive body of evidence on the association between HIs and civil war, that is, large-scale armed conflict between a government and an organized nonstate actor. (For comprehensive reviews of this literature, see Østby 2013; Bahgat et al. 2017; Hillesund et al. 2018.) In short, the relationship has been established across levels of analysis (country, group, sub-national region) and several types of inequality (political and socioeconomic) (Østby 2008b; Cederman, Weidmann, and Gleditsch 2011, Cederman, Gleditsch, and Buhaug 2013).

The association between socioeconomic HIs and civil war holds across various approaches to measurement. Most notably, researchers find a positive association when they use survey data to construct indices of socioeconomic HIs (Østby 2008b), as well as in studies that rely on geo-coded economic data mapped to the settlement areas of politically relevant ethnic groups (Cederman, Weidmann, and Gleditsch 2011, Cederman, Gleditsch, and Buhaug 2013, Cederman, Weidmann, and Bormann 2015). However, while HI researchers tend to agree that conflict can be initiated by the relatively privileged (topdogs in Galtung’s terminology) as well as the relatively deprived (underdogs), the econometric evidence that economically advantaged groups initiate conflict is less certain than the evidence for economically disadvantaged groups (Cederman et al. 2013).

Studies of political HIs rely almost exclusively on measures from the Ethnic Power Relations dataset family, usually in the form of exclusion from the executive (sometimes active discrimination) among politically relevant ethnic groups; or, in country-level studies, the share of the population that is excluded or discriminated. Finally, some HI studies include both economic and political HIs (e.g., Cederman, Gleditsch, and Buhaug 2013, Cederman, Weidmann, and Bormann 2015; Rudolfsen 2017; Cingranelli et al. 2019; Hillesund 2019; Alcorta, Swedlund, and Smits 2020; Tollefsen 2020; Treistman 2024).

The pioneering theoretical work on HIs (Stewart 2002, 2008), relative deprivation (Gurr 1970, 1993), and conflict was not confined to full-blown civil war. It encompassed a broader range of collective political violence forms, which all sort under what Galtung would refer to as direct violence.

The first econometric studies of HIs and lower intensity violence found positive associations for outcomes such as terrorism (Choi and Piazza 2016), electoral violence (Fjelde and Höglund 2016), and lethal social disorder (Østby 2016). Analyses of communal conflict—violence between loosely organized ethnic and communal groups—pointed in somewhat different directions. They found a positive relationship with socioeconomic inequality (Fjelde and Østby 2014), but mixed results for political exclusion (Fjelde and Østby 2014; Raleigh 2014).

Subsequent studies have focused on a variety of political violence outcomes, including civil conflict (Bodea, Elbadawi, and Houle 2017; Cingranelli et al. 2019; Das 2019; Hillesund 2019; Lessmann and Steinkraus 2019; Tollefsen 2020), nonstate conflict (Rudolfsen 2017; Alcorta, Smits, and Swedlund 2018; Hillesund 2019, Alcorta, Swedlund, and Smits 2020) coups (Bodea, Elbadawi, and Houle 2017; Houle and Bodea 2017), other forms of social unrest, such as ethnic and other riots (Bodea, Elbadawi, and Houle 2017; Cingranelli et al. 2019; McDoom et al. 2019; Abbs 2021) and domestic terrorism (Cingranelli et al. 2019; Fleming et al. 2020; Hansen, Nemeth, and Mauslein 2020; Treistman 2024). These studies too tend to find a positive relationship between HIs and various forms of violence.

In sum, the bulk of the existing empirical studies support the general conclusion that HIs breed political violence, which aligns with Galtung’s general thinking on the causal links between structural, cultural, and direct violence, which we summarized in the culture proposition (1.1). The evidence suggests that systematic disparities, when perceived through a cultural lens as unjust and enduring (which scholars tend to assume is the case with HIs) often fuel grievances that manifest in political violence.

Galtung, whose thinking emphasized systems and structures, would likely stress that the dynamics between certain types of HIs and conflict do not occur in a vacuum. Indeed, many HI-conflict studies point to the importance of accounting for contextual factors that may moderate the relationship. For example, some studies have found that natural resource wealth increases the conflict potential of political exclusion (Asal et al. 2016; Hunziker and Cederman 2017), some find that the combination of intra- and intergroup inequalities matter (Kuhn and Weidmann 2015), and Ives and Breslawski (2022)find that violence is particularly likely where political exclusion is combined with a certain level of education. Others have suggestd that the association between HIs and political violence is moderated by local institutions (Cao 2018), state strength (Ghatak 2018), individual deprivation (Nanes 2021), and mobilization capacity (Siroky 2020). However, despite many interesting contributions, we have yet to grasp the full picture of how various political, social, and demographic factors impact the relationship between various forms of HIs and various forms of political violence.

How Do Various Dimensions of Inequality Interact? Rank Disequilibrium and Violence

Galtung’s perspective of structural (dis)equilibrium has a parallel in theorizing on HIs and their multidimensionality. An ethnic group may experience rank disequilibrium, for example, if it is privileged economically but lacks political influence. Moreover, there can be salient differences between groups that are of a more cultural/symbolic nature, such as differential recognition of languages, flags, dress, or other traditions, which can also be used as means to suppress and discriminate (Stewart 2002). Practices and rhetoric that make use of such differences to legitimize inequalities and/or violence are a form of cultural violence, as Galtung (1990) defined it.

However, theories on HI differ from Galtung’s thinking in how various forms of inequality interact. That is, whether they act as catalysts for one another or, conversely, as mitigating factors. Galtung’s rank disequilibrium theory, as outlined above, predicts that groups residing at the very top or very bottom along all salient dimensions (complete topdogs and underdogs) should be the least belligerent. He expects rank disequilibria across dimensions, and the combination of motive and resources they come with, to facilitate organization and aggression. When HI scholars theorize about the interaction between dimensions of inequality, on the other hand, they tend to argue that different disadvantages enhance each other: political disadvantages motive group elites to take action and allow them to frame their grievance as the fault of the government, whereas economic disadvantages motivate ordinary group members to join the fight (Langer 2005; Cederman et al. 2013).

Overall, the econometric evidence appears to favor the catalysts argument over Galtung’s rank disequilibrium proposition. For example, recent research on vertical inequality suggests that the association between VI and political violence (short of civil war) is driven not by inequality itself but by the lack of social mobility that often accompanies it, and that low social mobility comes with less political violence (across many of its forms) (Houle 2019). This seems to contradict some of the implications of the rank disequilibrium hypothesis that Galtung discusses, such as his proposition that revolution will become more likely when mass education (or higher education) is introduced—which presumably increases mobility—without a corresponding increase in relevant positions (Galtung 1964, 107–8). It should be noted, however, that while the social mobility findings do not fit squarely with the rank disequilibrium argument, the two are not directly incompatible. While measures of social mobility capture situations where individuals move out of rank disequilibrium, they also include moves into it—two scenarios that, according to rank disequilibrium theory, have different implications for the likelihood of violence. For example, when a marginalized group gains educational access but remains economically or politically excluded, this partial upward mobility implies a move into rank disequilibrium, which can create frustration and increase the risk of conflict. Thus, high social mobility does not necessarily correspond to low rank disequilibrium, or vice versa.

Existing evidence on HIs and conflict challenges the rank disequilibrium hypothesis further, by showing that political inequalities between groups serve to amplify (or even activate) the conflict potential of economic group disadvantages (Langer 2005; Cederman et al. 2013; Cederman, Gleditsch, and Buhaug 2013, and Bormann 2015; Hillesund 2019). Or, translated into Galtung’s terminology: when looking at economic and political group rankings, severe aggression is most likely among the complete underdogs. This seems to contradict Galtung’s rank disequilibrium hypothesis, which predicted that complete underdogs (those equally deprived across all dimensions) should be less aggressive than groups and individuals in a position of rank disequilibrium, since disequilibrium motivates and facilitates (collective) action.

The contradiction has important implications for policy. If rank disequilibrium is an important cause of aggression, it becomes particularly important that policies aimed at reducing conflict by alleviating inequalities between groups work on all salient dimensions simultaneously (see Galtung 1964) to avoid a situation where the act of improving a group’s position relative to others along a single dimension of inequality results in more rather than less violence. If, on the other hand, overlapping dimensions of HI means generally more conflict, reduction of any dimension of HI could help alleviate conflict, regardless of whether other dimensions improve at the same time.

Yet, while most of the existing evidence seems to speak against the rank disequilibrium proposition, it would be premature to discard it. In fact, we think there is ample room for cross-fertilization between the approaches, including using the latter to develop new and testable hypotheses about how different dimensions of HI interact.

First, we need to account for various kinds of conflict. Certain HI studies indicate that groups in rank disequilibrium do initiate conflict, but that these are other types of conflict than the civil conflicts we see among the “complete underdogs.” That is, groups with political disadvantage who are socioeconomically better off are more likely to use (nonviolent) protest (under certain conditions) (e.g., Hillesund 2023). Groups with economic disadvantage who are represented in the government have a higher risk of communal violence (Hillesund 2019). Thus, while HI research might be seen to challenge the peacefulness of complete underdogs, it provides some support for the conflict potential of rank disequilibria, and underlines the need to take a broad view on what conflict is, which is arguably in the spirit of Galtung.

Second, the difference between various approaches may dissipate altogether if we account for more dimensions of inequality, beyond economic and political HIs. The groups whose disadvantage is both political and economic in nature, and whose risk of civil war is highest, may not be complete underdogs if we examine their ranking on other dimensions. Some of them could be better off (that is, higher ranked) on another salient dimension of inequality, such as HI in education or occupation. If the statistical association between combined disadvantage and civil war is driven by such groups, who are in fact in rank disequilibrium when we account for other dimension, accounting for these dimensions brings HI research into line with rank disequilibrium theory. Some of the evidence outlined above points in this direction, such as the finding that natural resource wealth and a certain level of education increase the conflict potential of political exclusion (Asal et al. 2016; Hunziker and Cederman 2017; Ives and Breslawski 2022). Further empirical testing of such interaction is a promising avenue for future research.

Third, it is possible that rank disequilibrium explains aggression in certain time periods or regions, and combined disadvantage (complete underdog status) in other periods and places. After all, Galtung developed his theory in the 1960s, whereas much of the evidence in HI research comes from the post-Cold War period. We leave for future theorizing and testing the question of what conditions could make either dynamic dominate over the other. For now, we contend that the empirical evidence base to date is not sufficient to draw clear conclusions with regard to support for the theory of rank disequilibrium.

Reciprocal Causality

Most inequality–conflict studies tend to rely on research designs that do not support strong causal claims. Few of these studies make specific attempts at causal inference designs.¹¹ The dominant focus in their theorizing is on the causal arrow that runs from inequality to violence. However, like Galtung, inequality–conflict scholars acknowledge that the arrow might run in the other direction too, that is, (direct) violence can exacerbate inequalities (structural violence).

A growing body of historical research suggests that war has played a paradoxically equalizing role in shaping the distribution of wealth. For example, Walter Scheidel, in The Great Leveler (2018), argues that significant reductions in inequality have historically occurred only in the wake of violent upheavals—including mass-mobilization warfare, revolutions, state collapse, and pandemics. These shocks, he contends, destroy capital, disrupt elite power structures, and create rare windows for radical redistribution. Among these forces, large-scale war—particularly the two World Wars—stands out as powerful “levelers” through their effects on physical capital, taxation, and institutional reform. This account builds on Scheve and Stasavage (2012), who provide empirical support for the idea that mass warfare fosters progressive taxation. Analyzing inheritance tax rates across nineteen countries over two centuries, they show that it was not democratization per se, but rather the demands for “equal sacrifice” during wartime, that led governments to impose heavier taxes on the wealthy. While Scheidel incorporates this work into his broader thesis, he is more skeptical about the durability of such redistributive gains in peacetime, emphasizing that, absent continued disruption, inequality tends to rebound.

Using a far shorter time span than the above works, Bircan, Brück, and Vothknecht (2017) offer a quantitative analysis of the relationship between violent conflict and income inequality. Focusing on 161 countries from 1960 to 2014, they examine how conflict affects vertical inequality, measured using the Gini coefficient. They argue that internal armed conflict tends to increase vertical inequality, particularly during and immediately after conflict. This rise is driven by economic disruptions that disproportionately affect the poorest segments of society, including falling wages, rising prices for capital-intensive goods, and reductions in social spending. Their findings show that inequality increases significantly during civil wars and continues to grow in the early post-conflict years, typically peaking 5–10 years after the war ends. Although these effects are not permanent, it may take two decades or more for inequality to return to pre-conflict levels. The impact is especially pronounced in countries that were relatively equal before the outbreak of conflict.

What about the impact of conflict and violence on HIs? The only example we are aware of that empirically addresses the reverse causality from conflict to inequality, focusing on HIs is Dahlum et al.’s (2019) background report the Human Development Report. The authors analyze intrastate conflicts in 120 countries from 1989 to 2018, using regional inequalities as a proxy for HI. They find that low-intensity conflicts do not significantly affect HI levels, but that intensity conflicts (over 1,000 battle deaths and lasting more than 5 years) are associated with significantly higher levels of HIs in the post-conflict phase, a pattern that persists for many years. This research, combined with previous studies showing that HI can lead to armed conflict, supports the idea of an inequality–conflict trap.

Dahlum et al.’s theoretical starting point is the literature focusing on how conflict in itself produces winners and losers. They argue that the characteristics of the conflict, and termination of the conflict, are important for understanding if and when a conflict–inequality trap will ensue. Notably, they argue that conflict diverts funds from public services to military spending, disproportionately affecting disadvantaged groups. Moreover, economic disruption primarily impacts unskilled labor, increasing inequality. Finally, conflicts often target specific areas or groups, leading to regional disparities. This all results in what they term an inequality–conflict trap. This concept aligns with Galtung’s (1990) model of the violence triangle, which includes direct, structural, and cultural violence at its vertices. Galtung posited that violence can originate from any of these points, move in any direction, and create self-perpetuating cycles of violence.

Taken together, the evidence on the reverse causal link—from violence to inequality—is limited and mixed. While large-scale wars may reduce inequality over the long term, as shown by Scheidel (2018) and Scheve and Stasavage (2012), studies covering shorter time spans (Bircan, Brück, and Vothknecht 2017; Dahlum et al. 2019) find that civil and intrastate conflicts can exacerbate both vertical and horizontal inequalities. These findings lend some support to Galtung’s idea of reciprocal causality between conflict and inequality, though more research is needed to capture the full complexity of this relationship and draw firm conclusions.

Discussion and Conclusions

Given the theory and evidence discussed above, what can we say about the usefulness and challenges of operationalizing Galtung’s ideas on inequality and conflict in contemporary peace and conflict research?

Before outlining some conclusions, let us reiterate that our focus on the macro-level relationship between inequalities and intra-state political violence only captures a portion of Galtung’s broader violence complex. Specifically, we assess the (primarily) one-way relationship between certain forms of structural violence and certain manifestations of direct violence, while assuming the role of cultural violence in this dynamic. Galtung’s theorizing encompasses a wider range of causal propositions, albeit often implicit rather than explicitly articulated. His concepts extend beyond political violence to include international inequality and less politically motivated forms of violence, which fall outside the scope of our discussion.

Traces of Galtung’s Influence in the Inequality–Conflict Literature

Galtung’s work offers some key insights that appear to have been picked up in later scholarship on inequality and conflict, without necessarily being attributed to him. First, his expansive concept of structural violence highlights the many forms inequalities can take and underscores their presence at all levels of society. This broad concept, together with his thinking on rank disequilibrium, calls attention to the multidimensionality of inequality, which is increasingly addressed in the empirical HI-conflict literature.

Second, there are some benefits to Galtung’s (clearly controversial) decision to label structural inequality as a form of violence. Most notably, it underscores inequalities’ potential to constitute a direct affront to basic human rights. This framing not only heightens awareness of the gravity of such inequalities but also paves the way for a broader understanding of peace—one that moves beyond the mere absence of physical violence.

Third, Galtung was among the first to acknowledge the multiple causal paths and cycles linking inequalities, culture, and direct violence—an area where empirical research continues to face challenges. While explicit references to Galtung are rare in studies examining the impact of direct violence on inequality, theoretical arguments and the emerging empirical findings indeed seem to support his idea that the causal arrow runs in both directions.

Assessing Galtung’s Causal Propositions: Some Empirical Support

In our assessment of key causal claims that Galtung makes on the relations between inequalities, culture, and violence, we found some empirical support for certain claims. First, there is support for the inequality–violence proposition: that is, that inequalities can foster violence. The proposition does not hold across the board, however. There is little evidence that inequalities between individuals (vertical inequalities) cause civil war. Also, their link to other forms of violence is tenuous and depends on levels of social (im)mobility.

The evidence is consistent and strong for inequalities between groups, across all the types of political violence covered in this study. This lends strong support to what we called the cultural proposition: that it matters whether inequalities (and violence) are legitimized by elements of a society’s culture. This is what Galtung labeled cultural violence.

Existing evidence on how various dimensions of HI interact—and on the role of social (im)mobility—appears to challenge the rank disequilibrium proposition. However, firm conclusions on this would require further research that systematically examines how multiple forms of inequality (beyond political and economic dimensions) intersect and identifies potential scope conditions under which the proposition may or may not hold. In this pursuit, we believe researchers could benefit from re-discovering and engaging more with Galtung’s work.

Finally, other causal chains and cycles, such as reverse and reciprocal causality, are often acknowledged by inequality and conflict scholars, but they are severely understudied. In line with Galtung’s broader propositions, there is some evidence that armed conflict can exacerbate both vertical and horizontal inequalities. However, some historical works actually find the opposite effect—that conflict reduces inequality over time. This clearly suggests that more studies are needed to conclude on the reciprocal causality proposition.

(Remaining) Challenges in Operationalizing and Testing Galtung’s Concepts

Despite some valuable insights offered by Galtung that are reflected in today’s scholarly literature on inequality and conflict, his concepts arguably present several challenges, particularly regarding their operationalization and theoretical scope. One of the primary criticisms is the normative nature of his ideas. By framing inequality as a form of violence, Galtung invites a value-laden interpretation that some scholars find contentious. This framing raises important questions about measurement and applicability within empirical studies, given that his concepts are broad and arguably not intended to be easily quantified. This said, in fairness, Galtung probably did not intend for them to be measurable either.

A second challenge concerns Galtung’s limited engagement with the pivotal role of group identity in conflict dynamics. He does not explicitly address how groups are formed or how identification processes drive collective grievances. HI theory fills this gap by emphasizing the group dimension of inequality and its critical role in overcoming the fragmentation and marginalization that Galtung describes as formidable barriers to organization among the “underdogs.” These barriers are often more difficult to overcome when inequality exists primarily between individuals (vertical inequality), as “class” tends to be a less pervasive identity marker than cultural or ethnic group affiliations. To some extent, this realization helps explain the differing empirical findings for vertical and horizontal inequalities.

Third, Galtung’s treatment of causality is notably vague. While he outlines multiple causal paths and cycles linking inequalities, culture, and direct violence, he provides few detailed justifications or real-life examples. His rather tautological definition of cultural violence as legitimizing other forms of violence further complicates its placement in a causal sequence. But again, Galtung’s main aim or ambition was probably not to offer the most easily testable theory in the first place.

Fourth, it is hard to determine where nonviolent mobilization fits in Galtung’s structural–cultural–direct violence complex. Logically, the mechanisms he describes as linking structural inequalities to direct violence (aggression) seem equally relevant for explaining nonviolent mobilization. That is, if Galtung is right that certain constellations of structural violence (such as HIs or rank disequilibria) come with motives and resources that let people overcome barriers to consciousness formation and organization, then nonviolent mobilization seems like an equally plausible outcome as violent conflict.

The empirical evidence on this is mixed. Recent studies on the link between HIs and nonviolent mobilization report both positive and zero associations (see, e.g., Cunningham 2013; Butcher and Svensson 2016; Thurber 2018; Bartusevičius and Gleditsch 2019; Rørbæk 2019; Basedau and Roy 2020; Germann and Sambanis 2021; Hillesund 2023).

Two recent findings can be interpreted as evidence that rank disequilibrium increases nonviolent mobilization: political HI (exclusion) is more likely to spur nonviolent mobilization (but not violence) under conditions of (i) democracy (i.e., systems with large minimum winning coalitions, meaning that individual political inequality is low; Choi and Kim 2018) and (ii) in the absence of economic HI (i.e., when groups possess some economic or educational resources; Hillesund 2023). This tentative support for the rank disequilibrium hypothesis when applied to nonviolent mobilization stands in contrast to the limited and mixed evidence we discussed for rank disequilibria and violent mobilization. The findings also suggest that to fully evaluate the rank disequilibrium hypothesis, we need to investigate interactions between horizontal and vertical forms of inequality.

Finally, both Galtung and HI scholars can be criticized for under-theorizing the agency of states and political regimes. The role of governments in perpetuating or mitigating structural inequalities and violence remains an underexplored aspect in both frameworks.

In sum, although not all of Galtung’s ideas are equally fruitful or easily lend themselves to empirical testing of the relationship between inequality and conflict, his contributions remain valuable and thought-provoking. The fact that some of his concepts generate more questions than answers can be frustrating, but it also offers a welcome challenge for those grappling with one of the oldest questions in political thought: how political discontent and its consequences—protest, instability, and violence—are shaped not only by the absolute level of wealth and privileges but also by its distribution. Galtung’s work invites us to confront these enduring issues, if anything, with a broader and more critical lens.

Acknowledgments

We thank the guest editors, Nils Petter Gleditsch and Gerald Schneider, for their valuable comments and suggestions. An earlier version of this paper was presented at the 66th ISA Convention in Chicago, IL, on March 4, 2025. We are grateful to Sara McLaughlin Mitchell for serving as discussant, and we also thank the other panel participants for their insightful questions and feedback. All remaining errors are our own.

Footnotes

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