Radicalization and violent extremism: Perspectives from research on group processes and intergroup relations

Abstract

Radicalization and violent extremism leading to violent protests, repression, and terrorist attacks constitute important issues in our world. Social psychological group processes and intergroup dynamics play a key role in creating resilience against or facilitating the path towards violent extremism. The present body of work brings together and furthers our understanding of these factors by integrating insights from other fields, most centrally political science. In this introductory article, we summarize the state of the literature and suggest a social psychological research agenda for studying radicalization and violent extremism. This agenda (a) focuses on how the radicalization process commences and festers in ordinary people; (b) is ambitious in bringing research into the real world with protesters, the repressed, and groups engaged in conflict; (c) is pragmatic in measuring outcomes of interest; and (d) applies field experimental methodology, among other methodologies. With this perspective, we argue, social psychology is ideally positioned for a new decade of impactful research into radicalization and violent extremism.

Keywords

violent extremism radicalization group relations political violence research agenda social identity

In the past two decades, radicalization and violent extremism have attracted the attention of citizens, journalists, scientists, and others interested in groups and group processes. After all, we have seen several instances of extremist ideologies and regimes, gruesome atrocities, dictatorial leadership, and violent intergroup conflict. Much attention has been paid to religious extremism as well as White supremacists. We have also seen instances of left-wing radicalization and repressive state reactions to various instances of extremist behaviors and terrorist attacks.

Violent extremism and terrorism associated with radicalizing religious groups have been commonplace in the past 20 years (Van den Bos, 2018). For example, Islamist radicalization and terrorism are responsible for events such as the coordinated attacks by al-Qaeda on the United States on 9/11 (2001), the murder of film-maker Theo van Gogh in Amsterdam (2004), the bomb attacks in Madrid (2004) and London (2005), the assault on the offices of the French satirical weekly newspaper Charlie Hebdo in Paris (January 2015), and the violent behavior by the Islamic State in Iraq and Syria (since 2014). Furthermore, there have been numerous large-scale religion- and ethnicity-based attacks in Afghanistan, Yemen, Niger, Nigeria, Syria, and elsewhere.

In recent years, ideological violence has increased worldwide (Institute for Economics and Peace, 2018), particularly due to increased activity from far-right and White supremacist extremist groups empowered by populism and dissatisfaction with the traditional political class (AON, 2018). For example, 2020 has served up the usual diet of terrorist attacks (e.g., 10 people were murdered in Hanau in Germany by a neo-Nazi who hated immigrants; and White supremacist violence has been on the rise in the United States, such as the neo-Nazi car attack in Charlottesville, Virginia). Social protests around the world have sometimes attracted violent subgroups and provoked violent reactions on the part of the authorities (e.g., Black Lives Matter demonstrations in the United States).

Despite notable differences, these and other acts of violent extremism share an important commonality; that is, notwithstanding that some who carry out violence do so alone or on their own accord, “lone wolves” are in fact rarely truly alone. In almost all cases, the actors believe they are promoting the religion, ideology, or world view of a victimized group they belong to (De Graaf & Van den Bos, 2020), and are doing so directly or indirectly against the victimizing, and often dehumanized, outgroup and/or its ideology. Whether supported by a small group of like-minded individuals or by a looser and larger sociopolitical, ethnic, or religious faction within or across their nation, group processes and intergroup relations play a central role.

Studying Radicalization and Violent Extremism

This central role has not been well reflected in social psychological research. That is now beginning to change, as witnessed by this special issue of Group Processes & Intergroup Relations (see also Doosje et al., 2007; Horgan, 2016; Kruglanski, Bélanger, & Gunaratna, 2020; Kruglanski, Webber, & Koehler, 2020; Moghaddam & Marsella, 2004; Van den Bos, 2018). Historically, the study of radicalization and intergroup violence has been influenced by specific societal and political events. Since 2001, and the terrorist attacks on September 11, the study of radicalization and violent extremism has become a research field in its own right, in tandem with an influx of research funding on preventive interventions (Kundnani, 2012; Sedgwick, 2010). While violent religious extremism has received much attention, the past decade has seen a renewed focus on revitalized right-wing and antiglobalization violence, as well as types of violence that cut across ideological lines, such as single-issue extremism (Horgan, 2016; Piazza, 2017). Research into radicalization and violent extremism has become a field of research, rather than a subject studied within different scholarly traditions.

A range of disciplines within psychology have played important parts in this research. For example, clinical psychology has pointed to the importance of isolation and subclinical disorder in radicalization (Gill et al., 2014; Gøtzsche-Astrup & Lindekilde, 2019); and research on personality and individual differences has explored the importance of factors such as trait anxiety, aggression, social dominance orientation, and authoritarianism (Doosje et al., 2013; Kalmoe, 2014; Thomsen et al., 2014). There is, however, general agreement across disciplines that the radicalization process always involves social psychological processes and phenomena (e.g., social interaction, social influence, social context, shared representations and identities, and so forth), and it is therefore within social psychology that we should expect to find the largest body of work on this subject.

Social psychology is particularly well suited to study radicalization and violent extremism for at least two reasons. First, social psychology has always been (or, by its definition, should be) the psychological discipline most closely engaged with large-scale contemporary social issues that have dramatic relevance for society (Fiske, 2013). For example, the Great Depression of the 1930s and the empowerment of Fascism fueled research on frustration and aggression; World War II fueled research on group dynamics, leadership, and attitude change and persuasion; the Holocaust energized research on authoritarianism; and the Cold War focused attention on large-scale intergroup conflict. Unsurprisingly, we can anticipate social psychology to help us understand one of the biggest issues of the early 21st century.

Second, social psychology adopts a particularly well-suited research methodology that helps identify causal processes pertaining to what people think, feel, and do in truly social contexts (Van den Bos, 2020a, 2020b). Defined as an empirical science of human interaction and influence, social psychology develops general theories to predict and explain behavior, conducts rigorous empirical and experimental studies to test these theories, and provides a comprehensive understanding of the individual as well as of the group. Because radicalization and violent extremism are complex multifaceted phenomena that are influenced by individual, group, and intergroup psychological processes and their interaction, social psychology provides a unique vantage point.

Apart from social psychology, the field of radicalization and violent extremism has been influenced strongly by political science (e.g., Henry et al., 2005; McCauley & Moskalenko, 2008). We first say a few words, in this introduction to the special issue, about the interplay of political science and social psychology in the study of violent extremism. We develop and present a classificatory model for understanding and studying radicalization and violent extremism. Finally, we introduce the nine individual papers included in the issue. Together they convey the state of the science, by showcasing the diversity of methods and theories, and of empirical data that spans the United States and Western Europe, to the Balkans and East Asia. We conclude by sketching out a possible future for a social psychology of radicalization and violent extremism.

Political Science and Social Psychology

Social, particularly political, scientists have often lamented a lack of empirical approaches to the study of radicalization (Silke & Schmidt-Petersen, 2017). However, contemporary reviews tell a slightly different story in which empirical methods (Schuurman, 2020) and even experimental designs (Gøtzsche-Astrup, 2020) are more common. This development is welcome, as there has, according to some commentators, been a trough in social psychological research on radicalization (Horgan, 2016). At the beginning of a new decade, we believe a special issue targeting interdisciplinary work in this field is timely, with a focus on social psychology and political science.

From the outset, the field of radicalization and violent extremism has acknowledged the need for an approach that crosses disciplinary boundaries and draws on a variety of social science disciplines, including anthropology (e.g., Atran, 2016), sociology (e.g., Della Porta, 2008), and economics (e.g., Blomberg & Hess, 2006). However, the largest and furthest developed interdisciplinary relationship is between political science and social psychology, and there are two main reasons for this.

First, the large interdisciplinary research centers on radicalization and violent extremism are predominantly interdisciplinary collaborations between psychology and political science departments. Examples include the Center for Research on Extremism (C-REX) at the University of Oslo, the Center for the Study of Radicalisation and Political Violence at King’s College London, and the National Consortium for the Study of Terrorism and Responses to Terrorism (START) at the University of Maryland.

Second, the literature in this area is dominated by interdisciplinary political science and social psychology journals such as Studies in Conflict and Terrorism, Aggression and Violent Behavior, Political Psychology, Terrorism and Political Violence, Journal of Conflict Resolution, and Aggressive Behavior (Gøtzsche-Astrup, 2018). As the author affiliations of the articles in this special issue reveal, social psychology and political science intertwine and bring fruitful cross-fertilization to the understanding of violent extremism. For social psychologists, we believe it is timely to bring these two disciplines even closer together, and that the approach is particularly relevant to social psychologists studying aggression and violence in the context of group processes and intergroup behavior.

Explaining Radicalization and Violent Extremism: Individual, Situation and Group, and Outcome

There is a range of psychological theories and approaches to studying radicalization and violent extremism. These approaches can be classified into three foci: factors that influence the individual psyche, the situations that are particularly conducive to radicalization, and the outcomes that each theory or tradition focuses on. Any given theory or approach can have more than one focus.

Individual

The first set of approaches focuses on attributes within the individual person such as values, personality traits, biological processes, and self and identity dynamics that help explain violent extremism. A focus on these factors allows us to hone in on why individual actors can come to be radicalized or come to engage in violent extremism. For example, the uncertainty-identity theory account of violent extremism (Hogg, 2014, in press) explains how identity-related self-uncertainty can propel people to identify strongly with highly distinctive groups that have populist identities and autocratic leaders, and to have stronger intentions to engage in violence in defense of the ingroup (Gøtzsche-Astrup, 2019, 2020; Hogg et al., 2013; Van den Bos, 2018).

In the related “quest for significance” theory, it is individual feelings of loss of personal significance that set the individual on a path that can end in violent extremism (Kruglanski et al., 2014); and in the devoted actor theory, it is the adoption of sacred, nonnegotiable, and absolute values that sow the seeds for extreme acts (Atran, 2016).

In this special issue, the role of power distance orientation and individual ethnocentric values are examples of explanations that represent this individual approach.

Situation and Group

The second focus is on the situations or contexts that, interacting with the person-centered factors, further facilitate the radicalization process. Sociological or historical approaches tap into this factor, albeit often to explain specific instances of extremism or political violence. Social psychological theories focus on broader factors applicable across historic and cultural settings. It is in this domain that we find explanations that focus on groups themselves and how such groups are posited relative to outgroups.

For example, for uncertainty-identity theory (Hogg, 2014, in press), the availability of highly entitative groups that satisfy the desire for strong norms and hierarchical leadership felt by highly uncertain individuals enables more extreme action on behalf of these groups, often to gain acceptance (e.g., Goldman & Hogg, 2016). In the “quest for significance” theory, common narratives of outgroup transgressions and interpersonal networks offer a restoration of significance or meaning, to the same effect (Webber & Kruglanski, 2018). These explanations are well equipped to explain specific instances of extremism, or the attraction of radical narratives among specific groups within a larger population.

The articles in this special issue that fall under our situations and groups classification illustrate the multifaceted nature of radicalization and violent extremism by targeting a multitude of instances such as repression by outgroups, group-induced anger, and poor interethnic contact between groups. Unsurprisingly, most of these articles place a strong emphasis on the role of small groups of like-minded individuals (Gøtzsche-Astrup, 2018). Here, violent extremism is explained by focusing on the social mechanisms underlying group processes and intergroup relations that can lead to and stem from radicalization and extremism. This level of analysis has the advantage of focusing on the groups within which most radicalization happens, while still allowing for context-level and person-level explanations.

Outcome

The third focus concerns the outcomes targeted by different theories. While theories focus on different aspects of our individual psyche and of intergroup processes, they also often attempt to explain different outcomes under the theme of radicalization. One oft-studied outcome is attitudinal support for and favorable opinions towards acts of violent extremism, such as terrorist attacks on civilians or state violence against dissenters. While proviolent attitudes are not illegal, they tend to violate societal or wider human norms—at least in most democratic countries (McCauley & Moskalenko, 2017). The “quest for significance” theory, for example, has focused on this outcome in some studies (Jasko et al., 2017).

A second approach is to focus on actual engagement in violent behavior. In many ways, this is the most important outcome to explain, because it is the one that has the most serious impact on people’s lives. While a focus on this outcome may have contributed to the early dearth of empirical, especially experimental, studies in the field of radicalization research (Schuurman, 2020), publicly available databases of individuals who carried out violent extremist acts are today accessible, for example through START at the University of Maryland.

A large body of literature, in particular in political science, has studied intentions to engage in violent behavior. Explaining intentions has real-world implications for understanding when the risk of actual violence is particularly high, and in designing interventions to prevent violent extremism. One early approach pointing to the relevance of behavioral intentions is Moskalenko and McCauley’s (2009) explanation of the distinction between activism and radicalism. In the articles in this special issue, intentions to engage in extreme acts of violence is an outcome that cuts across theories and designs. Measures of behavioral intentions are shown to be applicable to a range of issues such as violence surrounding the Yellow Vest protesters in France or Muslim anger and violent intentions against the West.

With this classificatory model of approaches to the scientific study of radicalization and violent extremism, we hope to provide a map, or rather a set of tools, for approaching this body of research. In what follows, we outline the central themes and findings of each article in this special issue, and end by summarizing the core themes and central takeaway from this body of research and sketching a future agenda for social psychological research on radicalization and violent extremism.

Introduction to the Articles

This special issue of Group Processes & Intergroup Relations contains nine articles that each advances our knowledge of radicalization and violent extremism from a group processes and intergroup relations perspective. The articles illustrate the breadth and diversity of approaches in identifying universal issues and in illuminating societal challenges. The research populations span from American and Western European samples to the Balkans, the Middle East, the Indian subcontinent, and East Asia, and together tell a story about the importance of social psychological processes in solving the challenge posed by extremist ideology and behavior.

The first three articles target a classic theme of scholarship on violent extremism, namely the effects of ideology and intergroup relations. Zwicker et al. (2020) show the real risk of extreme attitudes becoming psychologically entrenched and static. In two smaller studies (N = 397 and 291) and a large longitudinal study (N = 5,812), the authors show that extreme ideological positions tend to be stable over time. Orazani et al. (2020) find, from two studies (N = 633 and 632), that the perceived normalization of radical or extreme outgroup ideologies triggers intolerance of outgroups and support for restrictions on their basic rights. Adam-Troïan et al. (2020) show, in a sample of French Yellow Vest protesters (N = 523), how outgroup threat in the form of subjectively experienced police repression facilitate a radicalization of ingroup protest identity.

The fourth to sixth articles extend this perspective by focusing on the group. The interplay between groups and ideology is taken up by Bélanger et al. (2020), who argue in three studies (N = 331, 381, and 366) that strong ideological passion is related to a preference for more extreme social groups, propelling individuals towards the embrace of political violence. Renström et al. (2020) document in four studies (N = 104, 308, 1,041, and 40) that the aversive experience of social exclusion of people sensitive to rejection can lead them to embrace radical political groups, which again drives extreme behavior on behalf of that group. A possible accelerator of this is explored in three studies (N = 223, 147, and 225) by Ozer et al. (2020), which show that an uncertain attachment to ordinary daily life is associated with stronger identification with extreme groups and stronger endorsement of extremism.

The importance of the group extends beyond close groups of friends and family, to the nation or larger ethnic group. Međedović et al. (2020) find that ethnocentrism is a strong predictor of a militant extremist mindset, but also that positive intergroup contact is related to an amelioration of this mindset (N = 600). Obaidi et al. (2020) show, in four studies (N = 425, 402, 127, 366), that religious identity creates a global perceived ingroup, and that perceived threats to and repression of parts of this group strengthen intentions to violently defend that group, even across geopolitical borders. Finally, Travaglino and Moon (2020) focus on the group defined in terms of shared cultural norms, and in four studies (N = 601, 613, 120, and 151) show how stronger endorsement of power distance increases intentions to engage in radical and violent political action in the United States as well as in South Korea.

Combining Interdisciplinary Insights

We started out with the observation that despite a consensus on the central role played by group processes and intergroup relations in radicalization and violent extremism, knowledge of the mechanisms through which they facilitate or inhibit violent extremism is still in its early days (Van den Bos, 2018). By drawing on different disciplines, specifically social psychology and political science, several important points can be made. The common threads running through the articles point to an emerging branch of the literature on radicalization and violent extremism, which combines political science theories and insights with social psychological approaches and methods, and a general focus on group processes and intergroup mechanisms.

A central insight from these studies is that studying ordinary people enables us to extend our knowledge of the mechanisms that can, ultimately, produce intergroup hostilities and extremist violence. Because the participants in these studies are not selected because they are already extreme, they show us that we all, to some extent, have the capacity to move towards more extreme views and behavior. The perspective that all extremists are somehow categorically different from us, or possess essential qualities that make them prone to violence, hinders not only the illumination of mechanisms involved in the process of becoming an extremist, but also impedes the development of strategies to build effective interventions. The focus of the articles in this special issue is on normal, not exceptional, social psychological mechanisms as explanations for violent extremism. Nationalism and ethnocentrism, intergroup contact, inclusion and exclusion from groups, and periods of uncertain social identities facilitate or hinder the radicalization process.

Furthermore, the articles showcase the value of interdisciplinary approaches to social and behavioral science research—substantially, methodologically, and statistically. Substantially, a shared aspect of the articles is the focus, common in the political science literature, on particular political events and real-world issues to increase the ecological validity of findings. When investigating the effects of global religious identity, therefore, a sample of European and Middle Eastern Muslims participate. When focusing on ethno-nationalist cleavages, investigators travel to the Balkans to collect their data. And when police repression is the focus, a study is conducted among protesters from the French Yellow Vest movement. Another fruitful combination of these two traditions, political science and social psychology, lies in the combination of the focus on (a) large and impersonal or imagined groups common in political science such as a nation or religion, and (b) the tighter knit intimate groups such as ideologically extreme cells or participants in local protests that more often figure in social psychology.

The methodological and statistical value comes from the combination of field studies and large-sample designs common in political science with the causal logic of experiments and structural equation modelling techniques more often seen in social psychology. Together, this integration helps balance internal validity with generalizability outside the proverbial laboratory.

A final common insight from these studies lies in the use of indicators of radicalization and violent extremism that do not suffer from some of the limitations of a strict focus on actual engagement in violence, for example a shrinking of the research participant pool to those who were previously or currently engaged in extremism. One relevant indicator, or target behavior, is ideological change towards more extreme ideas (Međedović et al., 2020; Orazani et al., 2020) or more extreme identities (Bélanger et al., 2020; Ozer et al., 2020). The most promising avenue, however, may lie in a focus on intentions to engage in radical or violent extremist behavior. With this approach, which four of the nine articles adopt (Adam-Troïan et al., 2020; Obaidi et al., 2020; Renström et al., 2020; Travaglino & Moon, 2020), it becomes possible to investigate directly the kinds of behavior that we are interested in, and that research on radicalization and violent extremism should help to explain and to prevent. At the same time, the substantial variation among participants on the measures used in the articles indicates that the measures remain meaningful for ordinary people under extraordinary circumstances.

Conclusion and a Research Agenda

The research presented here, in the context of wider consideration of the literature, suggests a broad social psychological and political science agenda for studying radicalization and violent extremism that can be expressed in terms of four guidelines or principles:

Direct attention towards ordinary people and focus on shared psychological processes to understand how the path towards violent extremism and radicalization commences and festers rather than focusing solely on the outcome of the process.

Be ambitious in reaching research participants for whom radicalization and violent extremism is directly and immediately relevant, such as protesters, people subjected to repression, religious minorities, or ethnic majorities in countries with intergroup conflict.

Do not fixate on measuring the final outcome of actual engagement in violence only; shifts towards more extreme ideology, support for violent extremists, endorsement of populist autocratic leaders, or hypothetical intentions to engage in violence can uncover causal links and inform community interventions as well as national and international policy.

Many different methodologies are relevant when studying radicalization and violent extremism in intergroup settings. Of particular methodological relevance are field experiments, as they combine the causal logic relevant for uncovering the pathways to violent extremism with the real-world relevance of politically and historically situated intergroup issues.

From its inception, social psychology has set the goal of leveraging knowledge about our individual and group psychology to inform social issues and to engender social change. It is with this perspective that we should seek to explore the issue of radicalization and violent extremism. We believe that these guidelines for a research agenda and the findings from the articles in this special issue contribute to this.

Footnotes

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

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