During the last few years there has been considerable interest in the role that social networks play in processes of radicalisation, whether we are talking about individual or collective radicalisation, and whether we are talking about ideological or tactical radicalisation, or both. There are a number of factors that account for this interest. First, study after study has pointed to the importance of social networks for processes of socialisation into radical social or political action. Even in the case of lone actor perpetrators of political violence, the idea that such people operate entirely in isolation has over the years been worn down by empirical analyses highlighting how many of these individuals engage with wider networks of similarly-minded activists (Gable and Jackson 2007, Gill and Corner 2015, Pantucci 2011, Sageman 2008, Weimann 2012). Second, there is growing recognition that in the contemporary context non-state political violence itself is often carried out by loosely coordinated networks of actors rather than more formalised groups; and third, the fact that new information and communication technologies have enabled us to trace and analyse these networks in ways that were not previously possible (see Carter, Maher, and Neumann 2014, Chipev et al. 2013, Fisher 2012, Kim et al. 2013, O’Callaghan et al. 2013).
In this presentation I will outline some of the mechanisms through which social networks contribute to processes of radicalisation, as well as giving some sense of the types of networks that appear to be most conducive to such processes.
How social networks contribute to processes of radicalisation
In order to think about how social networks can contribute to processes of radicalisation it is helpful to break the discussion down into two parts relating to:
- Processes of recruitment into activism, and
- Processes of tactical and ideological radicalisation post-recruitment.
Processes of recruitment
The importance of pre-existing social ties is a recurring theme in studies of people’s journeys into radical political activism. Indeed, in several studies it has been observed that recruitment can often precede ideological engagement (Blee 2003, Busher 2015, Ch 2, Fangen 1998, Ranstorp 2010). Such findings are very much in keeping with the wider literature on participation in social movements (McAdam 1986, Nepstad and Smith 1999, Snow, Zurcher, and Ekland-Olson 1980). So what are the mechanisms through which social networks contribute to processes of recruitment into radical political activism?
- Information channels and frame acquisition
Social networks provide an avenue through which prospective participants can come into contact with information about ‘the cause’ and the groups mobilising around this cause. Importantly, the informality and often private nature of these communication channels means that they are not controlled by mainstream media, political elites or the state (Neumann 2013).
- Processes of identification
The forging of collective identities is a crucial element in achieving sustained mobilisation (Casquete 2006, Hunt and Benford 2004, Melucci 1995, Taylor and Whittier 1992). Existing social ties can facilitate such processes (Passy 2003, 23). If my friends are part of a group that identify with a particular issue or collective identity I am also more likely to identify with and feel an affective bond with that issue, or collective identity: ‘We accept a friend’s invitation to a rally because we like her, or because we fear her disapproval if we turn her down, not just because we agree with her’ (Goodwin, Jasper, and Polletta 2001, 8).
This is why networks in which social ties are characterised by strong emotional bonds can provide particularly effective channels for recruitment – informal kinship or close friendship networks are often prominent in accounts of entry into radical political activism (Alonso 2010, Blee 2003, Freilich and Pridemore 2005, Sageman 2004). One of the critical questions for contemporary analysts is how, and the extent to which, the kind of deep emotional bonds that can facilitate radicalisation might be generated through online, non-face-to-face communications.
- Facilitating first contacts
A third mechanism is what Passy (2003) calls a ‘structural-connection function’. As well as enabling information flows and helping to stimulate processes of identification, social networks provide concrete opportunities for participation (McAdam 1986, Snow, Zurcher, and Ekland-Olson 1980). When I was talking with EDL activists, even people with a long history of participation in far right activism or in football hooliganism described how they had felt a certain sense of trepidation about attending their first EDL demonstrations: would they know anybody there? Would they fit in? Would they find anybody to talk to? Would it be what they hoped it would be? Personal ties smoothed these first contacts and put prospective participants at ease (Busher 2015).
Authority figures within the movement can be particularly effective recruiters (Alonso 2010, Passy 2003), perhaps, Passy argues, because such figures are well placed to address the doubts and uncertainties of prospective participants. Social networks that enable prospective participants to come into contact with such figures are likely therefore to be particularly effective at encouraging participation.
- Group decision-making
While some individuals may make a personal decision to become involved in a political movement, decisions to engage in political activism are often at least to some extent collective decisions (Marwell and Oliver 1993). We often find patterns of what Oberschall (1973) calls ‘block recruitment’, wherein whole groups of individuals chose to become involved in a specific movement: a group from a particular church may decide to join the civil rights movement, a group of hooligans from a particular football club may decide collectively to go along to an anti-Muslim street protest and so forth (see also della Porta 1988, 2003, McCauley and Moskalenko 2008, Sageman 2004).
Social networks and post-recruitment processes of radicalisation
Social networks also shape processes of radicalisation post-recruitment. Once again, the literature indicates a number of mechanisms through which this might happen.
- Tactical learning
Perhaps most obviously, social networks often ‘facilitate learning by providing the connections through which network participants share information and experience’ (Kenney et al. 2013, see also Gill and Corner 2015).
- Confirmation bias
Social networks, as Sunstein (2009, 24) argues, ‘can operate as polarization machines because they help to confirm and thus amplify people’s antecedent views.’ Entering into radical political activism alters a person’s social networks. In some cases activists are encouraged by leaders and co-activists to sever ties with people outside the group (Bjørgo 1998, Wasmund 1986), but even where this is not the case radical political activism often becomes the centre of participants’ lives (Blee 2003, Busher 2015, Simi and Futrell 2010). Such selective patterns of interaction make people more likely to be sharing ideas and experiences with like minds (Gill and Corner 2015, Husain 2007), which in turn makes them more likely to become drawn into forms of ‘group-think’ conducive to further ideological or tactical radicalisation (Klatch 2004, 497, NYPD 2007, 43). This is why the social networks that are most conducive to radicalisation are usually those that in effect leave participants cut off from wider social and cultural influences (della Porta 2003, della Porta and Tarrow 1986).
- Shaping conceptions of legitimate action
Activists in all social movement groups develop their tactical tastes and craft their conception of legitimate action through interactions with co-activists and other fellow ideological travellers (Tarrow 1993, Tilly 1986). People associated with radical forms of political action are no different. Again, this is why groups that encourage participants to sever social ties with wider society are particularly prone to tactical radicalisation.
The social ties that people form as they become involved in radical political movements also help to inhibit desistance – they make people less inclined to leave even when they may have doubts about the cause or the tactics being deployed (Bjørgo 2009, 1998, Miller McPherson, Popielarz, and Drobnic 1992). Sometimes this is due to threats of violence if they leave, but is also a function of the strength of the bonds produced through shared experiences of participation in radical political action (Busher 2015, Ch 6, della Porta 2003)
It is clear that by analysing social networks we can strengthen our capacity to understand, and perhaps even to some extent anticipate, patterns of radicalisation. What is also clear is that with new information and communication technologies we are today increasingly well placed to measure and describe these networks.
I would conclude however by drawing attention to three points that require reflection. First, there is a challenge associated with identifying causality when we talk about social networks and what they might or might not do. There is a danger that the argument becomes tautological – i.e. we find ourselves saying that people become part of particular (political) networks because they are already in some way linked into these networks, but we are still left with the problem of how people became embedded in these networks in the first place (Passy and Giugni 2000, 120). In order to cope with this challenge, we must recognise that networks are emergent, just as identities, issue frames and emotions are emergent and should therefore be very cautious about conceiving of them simply as an independent variable.
Second, network effects are extremely patchy. Social contacts with people who hold extreme political views or advocate the use of radical protest tactics do not always lead towards radicalisation, far from it. If we are to account for the patchiness of network effects it is important a) that we find ways of talking about social networks and their effects in ways that do not overlook human agency, and b) that we conceive of social networks as being both structural and cultural phenomena (Emirbayer and Goodwin 1994, Mische 2003, Passy and Giugni 2000) – as well as specifying what ties there are, we also need to say what people do with these ties, what they represent to the people who comprise the network, how these ties are initiated and, ideally, towards what ends.
Finally, and at the risk of stating the obvious, just as social networks may contribute to processes of radicalisation, they may also contribute to processes of deradicalisation or non-radicalisation. It is often the same intense personal ties that characterise and hold radical political groups together that also precipitate their collapse as groups are consumed by bitter squabbles and infighting (Busher 2015, Ch 5, Klatch 2004), and just as we see patterns of ‘block recruitment’ we can also find similar patterns of collective desistance from activism (Sandell 1999). Meanwhile, recent research (Bhui 2015) lends further credence to the idea that people who are anchored into wider society through multiple social networks are less susceptible to being drawn into or developing sympathies for extremist politics. When we study social networks in relation to a particular form of ‘problematic behaviour’, as well as exploring the social networks associated with risk we should also explore those social networks that may build resilience.
Alonso, R. 2010. “Radicalisation and Recruitment among Jihadist Terrorists in Spain: Main Patterns and Subsequent Counter-Terrorist Measures.” In Understanding Violent Radicalisation: Terrorist and Jihadist Movements in Europe, edited by M. Ranstorp, 207-230. Abingdon: Routledge.
Bhui, K. 2015. “Extremism’s False Trail.” New Scientist 226 (3016):24-25.
Bjørgo, T. 1998. “Entry, Bridge-Burning and Exit Options: What Happens to Young People who Join Racist Groups and Want to Leave.” In Nation and Race: The Developing Euro-American Racist Subculture, edited by J. Kaplan and T. Bjørgo, 231-258. Boston: Northeastern University Press.
Bjørgo, T. 2009. “Processes of Disengagement from Violent Groups of the Extreme Right.” In Leaving Terrorism Behind: Individual and Collective Disengagement, edited by T. Bjørgo and J. Horgan, 30-48. London: Routledge.
Blee, K.M. 2003. Inside Organized Racism: Women in the Hate Movement. Paperback ed. Berkeley: University of California Press.
Busher, J. 2015. The Making of Anti-Muslim Protest: Grassroots Activism in the English Defence League. Abingdon: Routledge.
Busher, J., and G. Macklin. 2014. “Interpreting ‘Cumulative Extremism’: Six Proposals for Enhancing Conceptual Clarity.” Terrorism and Political Violence Available Online First.
Carter, J.A., S. Maher, and P. Neumann. 2014. #Greenbirds: Measuring Importance and Influence in Syrian Foreign Fighter Networks. London: International Centre for the Study of Radicalisation and Political Violence.
Casquete, J. 2006. “Protest Rituals and Uncivil Communities.” Totalitarian Movements and Political Religions 7 (3):283-301.
Castells, M. 1996. The Rise of the Network Society Oxford: Blackwell.
Castells, M. 2012. Networks of Outrage and Hope: Social Movements in the Internet Age. Cambridge: Polity Press.
Chipev, B., P. Gulian, V. Dinga, R. Zimerman, and I. Enache. 2013. Counter-Jihadist Literature: A Network of Radical Authors and Their Influence Online. Amsterdam: Digital Methods Initiative, University of Amsterdam.
Collins, R. 2001. “Social Movements and the Focus of Emotional Attention.” In Passionate Politics: Emotions and Social Movements, edited by J. Goodwin, J.M. Jasper and F. Polletta, 27-44. Chicago: Chicago University Press.
della Porta, D. 1988. “Recruitment Processes in Clandestine Political Organizations: Italian Left-Wing Terrorism.” International Social Movement Research 1:155-169.
della Porta, D. 1995. Social Movements, Political Violence, and the State: A Comparative Analysis of Italy and Germany. Cambridge: Cambridge University Press.
della Porta, D. 2003. “Violence and the New Left.” In International Handbook of Violence Research, Volume I, edited by W. Heitmeyer and J. Hagan, 383-398. Dordrecht: Kluwer Academic Publishers.
della Porta, D., and S. Tarrow. 1986. “Unwanted Children: Political Violence and the Cycle of Protest in Italy, 1966–1973.” European Journal of Political Research 14 (5-6):607-632.
Diani, M., and G. Lodi. 1988. “Three in One: Currents in the Milan Ecology Movement.” In International Social Movement Research, edited by B. Klandermans, H. Kriesi and S. Tarrow, 103-124. Greenwich: JAI.
Emirbayer, M., and J. Goodwin. 1994. “Network Analysis, Culture, and the Problem of Agency.” American Journal of Sociology 99 (6):1411-1454.
Fangen, K. 1998. “Living Out Our Ethnic Instincts: Ideological Beliefs Among Right-Wing Activists in Norway.” In Nation and Race: Developing Euro-American Racist Subculture, edited by J. Kaplan and T. Bjørgo, 202-30. Boston: Northeastern University Press.
Fisher, A. 2012. Collaborative Public Diplomacy: How Transnational Networks Influenced American Studies in Europe. Basingstoke: Palgrave Macmillan.
Freilich, J.D., and W.A. Pridemore. 2005. “A Re-assessment of State-level Covariates of Militia Groups.” Behavioral Sciences and Law 23 (4):527-546.
Gable, G., and P. Jackson. 2007. Lone Wolves: Myth or Reality? Ilford: Searchlight.
Gill, P., and E. Corner. 2015. “Lone Actor Terrorist Use of the Internet and Behavioural Correlates.” In Terrorism Online: Politics, Law and Technology, edited by L. Jarvis, S. Macdonald and T.M. Chen, 35-53. Abingdon: Routledge.
Goodwin, J., J.M. Jasper, and F. Polletta. 2001. “Introduction: Why Emotions Matter.” In Passionate Politics: Emotions and Social Movements, edited by J. Goodwin, J.M. Jasper and F. Polletta, 1-24. Chicago: University of Chicago Press.
Goodwin, J., and S. Pfaff. 2001. “Emotion Work in High-Risk Social Movements: Managing Fear in the U.S. and East German Civil Rights Movements.” In Passionate Politics: Emotions and Social Movements, edited by J. Goodwin, J.M. Jasper and F. Polletta, 282-302. Chicago: University of Chicago Press.
Gould, R.V. 1995. Insurgent Identities: Class, Community, and Protest in Paris from 1848 to the Commune. Chicago: University of Chicago Press.
Hunt, S.A., and R.D. Benford. 2004. “Collective Identity, Solidarity and Commitment.” In The Blackwell Companion to Social Movements, edited by D.A. Snow, S.A. Soule and H. Kriesi, 433-457.
Husain, E. 2007. The Islamist. London: Penguin.
Jenkins, B.M. 2007. Building an Army of Believers: Jihadist Radicalization and Recruitment. RAND Corporation.
Kenney, M., J. Horgan, C. Horne, P. Vining, K.M. Carley, M.W. Bigrigg, M. Bloom, and K. Braddock. 2013. “Organisational Adaptation in an Activist Network: Social Networks, Leadership, and Change in al-Muhajiroun.” Applied Ergonomics 44 (5):739-747.
Kim, G.J., J. Rademakers, M. Sanchez, and W. van Vucht. 2013. Online Activity of the English Defence League. Amsterdam: Digitial Methods Intitiative.
Klatch, R.E. 2004. “The Underside of Social Movements: The Effects of Destructive Affective Ties.” Qualitative Sociology 27 (4):487-509.
Lofland, J. 1966. Doomsday Cult: A Study of Conversion, Proselytization, and Maintenance of Faith. Englewood Cliffs: Prentice-Hall.
Macklin, G., and J. Busher. 2015. “The Missing Spirals of Violence: Four Waves of Movement-Countermovement Contest in Post-War Britain.” Behavioral Studies of Terrorism and Political Aggression 7 (1):53-68.
Marwell, G., and P. Oliver. 1993. The Critical Mass in Collective Action: A Micro-Social Theory. Cambridge: Cambridge University Press.
McAdam, D. 1982. Political Process and the Development of Black Insurgency, 1930-1970. Chicago: University of Chicago Press.
McAdam, D. 1986. “Recruitment to High-Risk Activism: The Case of Freedom Summer.” American Journal of Sociology 92 (1):64-90.
McCauley, C., and S. Moskalenko. 2008. “Mechanisms of Political Radicalization: Pathways Toward Terrorism.” Terrorism and Political Violence 20 (3):415-433.
Melucci, A. 1995. “The Process of Collective Identity.” In Social Movements and Culture, edited by H. Johnston and B. Klandermans, 41-63. London: UCL Press.
Miller McPherson, J., P.A. Popielarz, and S. Drobnic. 1992. “Social Networks and Organizational Dynamics.” American Sociological Review 57 (2):153-170.
Mische, A. 2003. “Cross-talk in Movements: Reconceiving the Culture-Network Link.” In Social Movements and Networks: Relational Approaches to Collective Action, edited by M. Diani and D. McAdam, 258-280. Oxford: Oxford University Press.
Morris, A.D. 1984. Origins of the Civil Rights Movement: Black Communities Organizing for Change. New York: The Free Press.
Nepstad, S.E., and C. Smith. 1999. “Rethinking Recruitment to High-Risk/Cost Activism: The Case of Nicaragua Exchange.” Mobilization 4 (1):25-40.
Nesser, P. 2010. “Joining Jihadi Terrorist Cells in Europe: Exploring Motivational Aspects of Recruitment and Radicalization.” In Understanding Violent Radicalisation, edited by M. Ranstorp, 87-114. Abingdon: Routledge.
Neumann, P.R. 2013. “Options and Strategies for Countering Online Radicalization in the United States.” Studies in Conflict and Terrorism 36 (6):431-59.
NYPD. 2007. Radicalisation in the West: The Homegrown Threat. New York: New York Police Department.
O’Callaghan, D., D. Greene, M. Conway, J. Carthy, and P. Cunningham. 2013. “An Analysis of Interactions Within and Between Extreme Right Communities in Social Media.” In Ubiquitous Social Media Analysis, edited by M. Atzmueller, A. Chin, D. Helic and A. Hotho, 88-107. Berlin/Heidelberg: Springer.
Oberschall, A. 1973. Social Conflict and Social Movements. Englewood Cliffs: Prentice-Hall.
Opp, K., and C. Gern. 1993. “Dissident Groups, Personal Networks, and Spontaneous Cooperation: The East German Revolution of 1989.” American Sociological Review 58 (5):659-680.
Pantucci, R. 2011. A Typology of Lone Wolves: Preliminary Analysis of Lone Islamist Terrorists. In Report for the International Centre for the Study of Radicalisation and Political Violence.
Passy, F. 2003. “Social Networks Matter. But How?” In Social Movements and Networks: Relational Approaches to Collective Action, edited by M. Diani and D. McAdam, 21-48. Oxford: Oxford University Press.
Passy, F., and M. Giugni. 2000. “Life-Spheres, Networks, and Sustained Participation in Social Movements: A Phenomenological Approach to Political Commitment.” Sociological Forum 15 (1):117-144.
Ranstorp, M. 2010. “Introduction.” In Understanding Violent Radicalisation: Terrorist and Jihadist Movements in Europe, edited by M. Ranstorp, 1-18. Abingdon: Routledge.
Sageman, M. 2004. Understanding Terror Networks. Philadelphia: University of Pennsylvania Press.
Sageman, M. 2008. Leaderless Jihad: Terror Networks in the Twenty-First Century. Philadelphia: University of Pennsylvania Press.
Sandell, R. 1999. “Organizational Life Aboard the Moving Bandwagons: A Network Analysis of Dropouts from a Swedish Temperance Organization, 1896-1937.” Acta Sociologica 42 (1):3-15.
Simi, P., and R. Futrell. 2010. American Swastika: Inside the White Power Movement’s Hidden Spaces of Hate. Plymouth: Rowman & Littlefield.
Snow, D.A., L.A. Zurcher, and S. Ekland-Olson. 1980. “Social Networks and Social Movements: A Microstructural Approach to Differential Recruitment.” American Sociological Review 45 (5):787-801.
Stark, R., and W.S. Bainbridge. 1985. The Future of Religion: Secularization, Revival and Cult Formation. Berkeley: University of California Press.
Sunstein, Cass R. 2009. Going to Extremes : How Like Minds Unite and Divide. New York, NY, USA: Oxford University Press, USA.
Tarrow, S. 1993. “Cycles of Collective Action: Between Moments of Madness and the Repertoire of Contention.” Social Science History 17 (2):281-307.
Taylor, V., and N.E. Whittier. 1992. “Collective Identity in Social Movement Communities: Lesbian Feminist Mobilization.” In Frontiers in Social Movement Theory, edited by A.D. Morris and C.M. Mueller, 104-129. New Haven: Yale University Press.
Tilly, C. 1986. “European Violence and Collective Action since 1700.” Social Research 53 (1):159-184.
Wasmund, K. 1986. “The Political Socialization of West German Terrorists.” In Political Violence and Terror: Motifs and Motivations, edited by P.H. Merkl, 191-228. Berkeley: University of California Press.
Watts, D.J. 2004. Six Degrees: The Science of a Connected Age. New York: Norton.
Weimann, G. 2012. “Lone Wolves in Cyberspace.” Journal of Terrorism Research 3 (2):75-90.
Wiktorowicz, Q. 2005. Radical Islam Rising: Muslim extremism in the West. Oxford: Rowman & Littlefield.
 Gill and Corner (2015, 40) for example note in their recent discussion of the cases of 119 lone actors who have sought to undertake acts of terrorism, ‘while our sample is defined by the fact that they “acted” alone, there is a lot of evidence to suggest that many of these lone actors interact with co-ideologues during their radicalisation and/or attack-planning. Just less than half (47.9 per cent) interacted face-to-face with members of a wider network of political activists, and 35.3 per cent did so virtually’. BACK UP TO TEXT
 Reflecting a broader societal trend towards becoming what some have referred to as a network society (Castells 1996, 2012, Watts 2004), in which social, media and communication networks are transformed into the primary mode of organization at all levels. BACK UP TO TEXT
 Although there has been some debate about the extent to which these networks emerge from the bottom up or are nurtured and exploited from the top down (i.e. by recruiters) (see Jenkins 2007, Sageman 2008, Wiktorowicz 2005). BACK UP TO TEXT
 Studies have highlighted how social networks facilitated recruitment into movements such as the civil rights movement (McAdam 1982, 1986, Morris 1984), environmental movements (Diani and Lodi 1988), the Paris Commune (Gould 1995), the Velvet Revolutions of Eastern Europe (Opp and Gern 1993), the East German civil rights movement (Goodwin and Pfaff 2001), leftist underground movements in Italy and Germany (della Porta 1988, 1995) and so forth. BACK UP TO TEXT
 Selective patterns of interaction are also more likely to bring activists into repeated and emotionally charged contact with people articulating views diametrically opposed to their own – for example, the EDL activists I knew often came into contact, usually online, with left-wing and Islamist opponents. These encounters serve to confirm emergent beliefs about the evil that they believe themselves to be fighting against, thereby further hardening their views and in some cases leading towards tactical radicalisation (Busher and Macklin 2014, Macklin and Busher 2015). BACK UP TO TEXT
 Gill and Corner (2015, 41) describe for example how Nidal Malik Hasan, the shooter at Ford Hood, sought out the opinion of Anwar al-Awlaki on whether he would be considered a martyr if he died in the commission of his planned act. BACK UP TO TEXT
 Our social ties may both directly and indirectly shape us, the way we think and the way that we behave, be we also do things with social ties – we use them to achieve our own goals. BACK UP TO TEXT
 Nesser (2010), for example adds valuable nuance to his discussion of the jihadist community in Europe through his observations about how while what he calls the ‘entrepreneurs’ and proteges’ tended to actively build networks the ‘receivers’ or ‘drifters’ tended to be carried along by networks. BACK UP TO TEXT