Radicalization in Correctional Systems: A Scoping Review of the Literature Evaluating the Effectiveness of Preventing and Countering Interventions


  • Nicolò Maria Iannello University of Palermo
  • Maria Grazia Lo Cricchio University of Basilicata
  • Pasquale Musso University of Bari
  • Ignazio Grattagliano University of Bari
  • Cristiano Inguglia University of Palermo
  • Alida Lo Coco University of Palermo


Deradicalization, Disengagement, Prison, Evaluation, Programs


Although several prevention and countering radicalization programs in correctional institutions have been carried out in Europe and worldwide, little is known about their effectiveness. Thus, the current scoping review aimed at reporting on the state of the art of the literature assessing and evaluating such actions, identifying knowledge gaps, and examining methods used to assess their successfulness and impact. A total of eight studies that met eligibility criteria were reviewed after performing a search on Scopus, Web of Science, and PsychInfo (Ebsco) databases: Two studies evaluated a reintegration initiative based in the Netherlands; four focused on an Australian disengagement program; and two offered insights on a rehabilitation program carried out in Sri Lanka. Findings were discussed according to their evaluation methods (qualitative, mixed-methods, and quantitative) and instruments. Results highlighted that the evaluation process is still confronted with several methodological difficulties, such as a lack of agreement on how to univocally define and measure success and the identification of uniform indicators of deradicalization and disengagement. Additionally, results revealed that the effectiveness of these interventions is predominantly based on anecdotal evidence rather than on rigorous, empirical proofs. As such, it was not possible to compare these programs and determine which worked best. Suggestions for future research and practical implications for policymakers, prison governors, and practitioners are offered in the concluding section of this work.



The present study was made possible by funding from SERENY (“Strengthening approaches for the prevention of youth radicalisation in prison and probation settings”), a project co-funded by the Justice Program of the European Union, GA no. 101007425. The contents of this publication are the sole responsibility of the authors and can in no way be taken to reflect the views of the European Commission.


Anderson, S., Allen, P., Peckham, S., & Goodwin, N. (2008). Asking the right questions: Scoping studies in the commissioning of research on the organisation and delivery of health services. Health Research Policy and Systems, 6, 7. https://doi.org/10.1186/1478-4505-6-7.

Asrori, S., Jamilah, J., & Ismail, M. (2020, March). The challenge of radicalization and deradicalization in prison; A review on social dynamics prison officers and terrorist inmates. In ICSPS 2019: Proceedings of the 5th International Conference on Social and Political Sciences, ICSPS 2019, 12th November 2019, Jakarta, Indonesia (p. 84-91). European Alliance for Innovation.

Axelsson, J., Eriksson, L., & Grip, L. (2023). Managing violent extremist clients in prison and probation services: A scoping review. Terrorism and Political Violence. https://doi.org/10.1080/09546553.2023.2169144.

Barrelle, K. (2015). Pro-integration: Disengagement from and life after extremism.

Behavioral Sciences of Terrorism and Political Aggression, 7, 129–142.


Basra, R., & Neumann, P. R. (2016). Criminal pasts, terrorist futures: European jihadists and the new crime-terror nexus. Perspectives on Terrorism, 10, 25–40.

Beelmann, A. (2020). A social-developmental model of radicalization: A systematic integration of existing theories and empirical research. International Journal of Conflict Violence, 14, 1–14. https://doi.org/10.4119/ijcv-3778.

Borum, R. (2014). Psychological vulnerabilities and propensities for involvement in violent extremism. Behavioral Sciences and the Law, 32, 286–305. https://doi.org/10.1002/bsl.2110.

Bove, V., & Böhmelt, T. (2022). Imprisonment and terrorism. Terrorism and Political Violence, 34, 1229-1240. https://doi.org/10.1080/09546553.2020.1768078.

Bucerius, S. M., Schultz, W., & Haggerty, K. D. (2023). “That shit doesn't fly”: Subcultural constraints on prison radicalization. Criminology, 61, 157-181. https://doi.org/10.1111/1745-9125.12327.

Campelo, N., Oppetit, A., Neau, F., Cohen, D., & Bronsard, G. (2018). Who are the European youths willing to engage in radicalisation? A multidisciplinary review of their psychological and social profiles. European Psychiatry, 52, 1–14. https://doi.org/10.1016/j.eurpsy.2018.03.001.

Chantraine, G., & Scheer, D. (2021). Performing the enemy? No-risk logic and the assessment of prisoners in “radicalization assessment units” in French prisons. Punishment & Society, 23, 260-280. https://doi.org/10.1177/1462474520952147.

Cherney, A. (2018). Supporting disengagement and reintegration: Qualitative outcomes from a custody-based counter radicalization intervention. Journal for Deradicalization, (17), 1–27.

Cherney, A. (2020). Evaluating interventions to disengage extremist offenders: A study of the proactive integrated support model (PRISM). Behavioral Sciences of Terrorism and Political Aggression, 12, 17–36. https://doi.org/10.1080/19434472.2018.1495661.

Cherney, A., & Belton, E. (2020). Assessing intervention outcomes targeting radicalized offenders: Testing the pro integration model of extremist disengagement as an evaluation tool. Dynamics of Asymmetric Conflict, 13, 193–211.


Cherney, A., & Belton, E. (2021). Evaluating case-managed approaches to counter radicalization and violent extremism: An example of the Proactive Integrated Support Model (PRISM) intervention. Studies in Conflict & Terrorism, 44, 625–645.


Cilluffo, F. J., Cardash, S. L., & Whitehead, A. J. (2007). Radicalization: Behind bars and beyond borders. Brown Journal of World Affairs, 13, 113–122.

Clifford, B. (2018). Radicalization in custody: Towards data-driven terrorism prevention in the United States Federal Correctional System. Program on extremism policy paper. The George Washington University.


Costa, V., Liberado, P., Esgalhado, G., Cunha, A. I., & das Neves, P. (2021). One size does not fit all: Exploring the characteristics of Exit programmes in Europe. Journal for Deradicalization, (28), 1–38.

Costabile, A., Musso, P., Iannello, N. M., Servidio, R., Bartolo, M. G., Palermiti, A. L., & Scardigno, R. (2021). Adolescent psychological well-being, radicalism, and activism: The mediating role of social disconnectedness and the illegitimacy of the authorities. Journal of Research on Adolescence, 31, 25–33. https://doi.org/10.1111/jora.12590.

Dalgaard-Nielsen, A. (2010). Violent radicalization in Europe: What we know and what we do not know. Studies in Conflict & Terrorism, 33, 797–814.


Dandurand, Y. (2015). Social inclusion programmes for youth and the prevention of violent extremism. In M. Lombardi, E. Ragab, V. Chin, Y. Dandurand, V. de Divitiis, & A. Burato (Eds.), Countering radicalisation and violent extremism among youth to prevent terrorism (pp. 23–36). Amsterdam, The Netherlands. IOS Press. https://doi.org/10.3233/978-1-61499-470-1-23.

Doosje, B., Moghaddam, F. M., Kruglanski, A. W., de Wolf, A., Mann, L., & Feddes, A. R. (2016). Terrorism, radicalization and de-radicalization. Current Opinion in Psychology, 11, 79–84. https://doi.org/10.1016/j.copsyc.2016.06.008.

Feddes, A. R., & Gallucci, M. (2015). A literature review on methodology used in evaluating effects of preventive and de-radicalisation interventions. Journal for Deradicalization, (5), 1–27.

Glazzard, A. (2022). Violent extremist disengagement and reintegration: A framework for planning, design and evaluation of programmatic interventions. Studies in Conflict & Terrorism. https://doi.org/10.1080/1057610X.2022.2098553.

González-Álvarez, J.L., Santos-Hermoso, J., Gómez, Á., López-Novo, J.L., Buquerín-Pascual, S., Pozuelo-Rubio, F., Fernández-Gómez, C., & Chiclana, S. (2022). A Theoretical, empirical, and methodologically based instrument to assess the risk of violent Jihadist radicalization in prisons: The DRAVY-3. Terrorism and Political Violence. Advance online publication. https://doi.org/10.1080/09546553.2022.2145194.

Gøtzsche-Astrup, O., van den Bos, K., & Hogg, M. A. (2020). Radicalization and violent extremism: Perspectives from research on group processes and intergroup relations. Group Processes & Intergroup Relations, 23, 1127–1136. https://doi.org/10.1177/1368430220970319.

Hafez, M., & Mullins C. (2015). The radicalization puzzle: A theoretical synthesis of empirical approaches to homegrown extremism. Studies in Conflict & Terrorism, 38, 958–975. https://doi.org/10.1080/1057610x.2015.1051375.

Horgan, J. (2008). Deradicalization or disengagement? A process in need of clarity and a counterterrorism initiative in need of evaluation. Perspectives on Terrorism, 2, 3–8.

Horgan, J., & Braddock, K. (2010). Rehabilitating the terrorists? Challenges in assessing the effectiveness of de-radicalization programs. Terrorism and Political Violence, 22, 267–291. http://dx.doi.org/10.1080/09546551003594748.

Iannello, N. M., Musso, P., Palermiti, A. L., Bartolo, M. G., Servidio, R., Scardigno, R., Cheah, C. S. L., Lo Coco, A., & Costabile, A. (2021). Il processo di radicalizzazione nei giovani. Una rassegna sistematica dei fattori di rischio e di protezione nel contesto europeo [The radicalization process among youth. A systematic literature review of risk and protective factors in Europe]. Giornale Italiano di Psicologia, 3, 635–662.


Jones, C.R. (2014). Are prisons really schools for terrorism? Challenging the rhetoric on prison radicalization. Punishment & Society, 16, 74-103. https://doi.org/10.1177/1462474513506482.

Jugl, I., Lösel, F., Bender, D., & King, S. (2021). Psychosocial prevention programs against radicalization and extremism: A meta-analysis of outcome evaluations. The European Journal of Psychology Applied to Legal Context, 13, 37–46.


Khosrokhavar, F. (2013). Radicalization in prison: The French case. Politics, Religion & Ideology, 14, 284–306. http://dx.doi.org/10.1080/21567689.2013.792654.

King, M., & Taylor, D. M. (2011). The radicalization of homegrown Jihadists: A review of theoretical models and social psychological evidence. Terrorism and Political Violence, 23, 602–622. https://doi.org/10.1080/09546553.2011.587064.

Koehler, D. (2017). Preventing violent radicalization: Programme design and evaluation. In D. Muro (Ed.), Resilient cities. Countering violent extremism at local level (pp. 91–98). Barcelona: Cidob Edicions.

Kruglanski, A. W., Bélanger, J. J., Gelfand, M., Gunaratna, R., Hettiarachchi, M., Reinares, F., Orehek, E., Sasota, J., & Sharvit, K. (2013). Terrorism – A (self) love story: Redirecting the significance quest can end violence. American Psychologist, 68, 559–575.


Kruglanski, A. W., Chen, X., Dechesne, M., Fishman, S., & Orehek, E. (2009). Fully committed: Suicide bombers’ motivation and the quest for personal significance. Political Psychology, 30, 331–557. https://doi.org/10.1111/j.1467-9221.2009.00698.x.

Kruglanski, A. W., Gelfand, M. J, Bélanger, J. J., Gunaratna, R., & Hettiararchchi, M. (2014). De-radicalising the Liberation Tigers of Tamil Eelam (LTTE): Some preliminary findings. In A. Silke (Ed.), Prisons, terrorism and extremism: Critical issues in management, radicalization and reform (pp. 183–196). Oxon: Routledge.

Lipsey, M., Petrie, C., Weisburd, D., & Gottfredson, D. (2006). Improving evaluation of anti-crime programs: Summary of a National Research Council report. Journal of Experimental Criminology, 2, 271-307. https://doi.org/10.1007/s11292-006-9009-6.

Marsden, S. V. (2015). Conceptualising ‘success’ with those convicted of terrorism offences: Aims, methods, and barriers to reintegration. Behavioral Sciences of Terrorism and Political Aggression, 7, 143–165. https://doi.org/10.1080/19434472.2014.1001421.

Maskaliūnaitė, A. (2015). Exploring the theories of radicalisation. International Studies - Interdisciplinary Political and Cultural Journal, 17, 9–26.


McBride, M. K., Carroll, M., Mellea, J., Hughes, D., & Savoia, E. (2022). Evaluating terrorist and extremist reintegration programming: A systematic literature review. Journal for Deradicalization, (32), 35–75.

McGilloway, A., Ghosh, P., & Bhui, K. (2015). A systematic review of pathways to and processes associated with radicalization and extremism amongst Muslims in Western societies. International Review of Psychiatry, 27, 39–50.


Moher D., Liberati, A., Tetzlaff, J., Altman, D. G., & the PRISMA Group (2009). Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. Plos Med, 6, e1000097. https://doi.org/10.1371/journal.pmed.1000097.

Morrison, J. F., Silke, A., Maiberg, H., Slay, C., & Stewart, R. (2021). A systematic review of post-2017 research on disengagement and deradicalisation. Full report. Centre for Research and Evidence on Security Threats. https://crestresearch.ac.uk/resources/a-systematic-review-of-post-2017-research-on-disengagement-and-deradicalisation/

Munn, Z., Peters, M. D. J., Stern, C., Tufanaru, C., McArthur, A., & Aromataris, E. (2018). Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC Medical Research Methodology, 18, 143. https://doi.org/10.1186/s12874-018-0611-x.

Neumann, P. (2010). Prisons and terrorism radicalisation and de-radicalisation in 15 countries. London: International Centre for the Study of Radicalisation and Political Violence.


Pistone, I., Erikkson, E., Beckman, U., Mattson, C., & Sager, M. (2019). A scoping review of interventions for preventing and countering violent extremism: Current status and implications for future research. Journal for Deradicalization, (19), 1-84.

Radicalisation Awareness Network (2016). Dealing with radicalisation in a prison and probation context. RAN P&P - practitioners working paper. https://home-affairs.ec.europa.eu/system/files_en?file=2016-12/ran_p_and_p_practitioners_working_paper_en.pdf

Radicalisation Awareness Network (2019). Preventing radicalization to terrorism and violent extremism. Approaches and practices. EU Commission.


Renard, T. (2020) Overblown: Exploring the gap between the fear of terrorist recidivism and the evidence. CTC Sentinel, 13, 19–29.

Ronco, D., Sbraccia, A., & Torrente, G. (2019). Prison de-radicalization strategies, programmes and risk assessment tools in Europe. Antigone Edizioni. https://iris.unito.it/bitstream/2318/1720819/1/Prison%20de-radicalization%20strategies.pdf

Schultz, W. J., Bucerius, S. M., & Haggerty, K. D. (2021). The floating signifier of “Radicalization.” Correctional officers’ perceptions of prison radicalization. Criminal Justice and Behavior, 48, 828–845. https://doi.org/10.1177/0093854820969749.

Schuurman, B., & Bakker, E. (2015). Reintegrating jihadist extremists: Evaluating a Dutch initiative, 2013-2014. Behavioral Sciences of Terrorism and Political Aggression. http://dx.doi.org/10.1080/19434472.2015.1100648.

Silke, A. (2011). Disengagement or deradicalization: A look at prison programs for jailed terrorists. CTC Sentinel, 4, 18–21.

Silke, A., & Veldhuis, T. (2017). Countering violent extremism in prisons: A review of key recent research and critical research gaps. Perspectives on Terrorism, 11, 2–11.

Sinai, J. (2014). Developing a model of prison radicalization. In A. Silke (Ed.), Prisons, Terrorism and Extremism: Critical Issues in Management, Radicalisation and Reform (pp. 35–46). Oxon: Routledge.

Sjøen, M. M., & Jore, S. H. (2019). Preventing extremism through education: Exploring impacts and implications of counter-radicalisation efforts. Journal of Beliefs & Values, 40, 269–283. https://doi.org/10.1080/13617672.2019.1600134.

Sklad, M., & Park, E. (2017). Examining the potential role of education in the prevention of radicalization from the psychological perspective. Peace and Conflict: Journal of Peace Psychology, 23, 432–437. https://doi.org/10.1037/pac0000258.

Smith, L. G. E., Blackwood, L., & Thomas, E. F. (2020). The need to refocus on the group as the site of radicalization. Perspectives on Psychological Science, 15, 327–352. https://doi.org/10.1177/1745691619885870.

Speckhard, A. (2011). Prison and community-based disengagement and de-radicalization programs for extremist involved in militant jihadi terrorism ideologies and activities. In A. Speckhard (Ed.), Psychosocial, organizational and cultural aspects of terrorism (pp. 1 – 14). Neuilly-sur-Seine: NATO-Research and Technology Organisation. https://citeseerx.ist.psu.edu/viewdoc/download?doi=

Thompson, N. (2016). Root cause approach to prisoner radicalization. Salus Journal, 4, 18–33.

Tiscini, G., & Lamote, T. (2019). The process of radicalization in the prison environment: From criminogenesis to radicalogenesis. L’Evolution Psychiatrique, 84, e59–e69. https://doi.org/10.1016/j.evopsy.2019.05.003.

van der Heide, L., & Schuurman, B. (2018). Reintegrating terrorists in the Netherlands: Evaluating the Dutch approach. Journal for Deradicalization, (17), 196–239.

Veldhuis, T. (2012). Designing rehabilitation and reintegration programs for violent extremist offenders: A realist approach. The Hague, The Netherlands: International Centre for Counter-Terrorism. https://www.icct.nl/sites/default/files/import/publication/ICCT-Veldhuis-Designing-Rehabilitation-Reintegration-Programmes-March-2012.pdf

Vidino, L., & Clifford, B. (2019). A review of transatlantic best practices for countering radicalisation in prisons and terrorist recidivism. Paper presented at the 3rd Conference of the European Counter Terrorism Centre (ECTC) Advisory Network on Terrorism and Propaganda. https://www.europol.europa.eu/cms/sites/default/files/documents/a_review_of_transatlantic_best_practices_for_countering_radicalisation_in_prisons_and_terrorist_recidivism.pdf

Webber, D., Chernikova, M., Kruglanski, A. W., Gelfand, M. J., Hettiarachchi, M., Gunaratna, R., Lafreniere, M. A., & Belanger, J. (2018). Deradicalizing detained terrorists. Political Psychology, 39, 539–556. https://doi.org/10.1111/pops.12428.

Williams, R. J. (2016). Approaches to violent extremist offenders and countering radicalisation in prison and probation. RAN Working Paper (2nd ed.). https://home-affairs.ec.europa.eu/system/files_en?file=2020-09/ran_pp_approaches_to_violent_extremist_en.pdf

Williams, M. J., & Kleinman, S. M. (2014). A utilization-focused guide for conducting terrorism risk reduction program evaluations. Behavioral Sciences of Terrorism and Political Aggression, 6, 102-146. https://doi.org/10.1080/19434472.2013.860183.

Williams, R., & Liebling, A. (2023). Do prisons cause radicalization? Order, leadership, political charge and violence in two maximum security prisons. The British Journal of Criminology, 63, 97-114. https://doi.org/10.1093/bjc/azab122.

Wolfowicz, M., Litmanovitz, Y., Weisburd, D., & Hasisi, B. (2021). Cognitive and behavioral radicalization: A systematic review of the putative risk and protective factors. Campbell Systematic Reviews, 17, e1174. https://doi.org/10.1002/cl2.1174.