Research and analysis

Current evidence around the cause of violence-fixated individuals

Published 24 September 2026

This is not a statement of government policy.

Rapid projects support government departments to understand the scientific evidence underpinning a policy issue or area by convening academic, industry and government experts at a single roundtable. These summary meeting notes seek to provide accessible science advice for policymakers. They represent the combined views of roundtable participants at the time of the discussion and are not statements of government policy.

This publication considers the following question, taken from a meeting note of a roundtable chaired by Professor Dame Angela McLean (Government Chief Scientific Adviser) facilitated by the Government Office for Science on 5 March 2025.

What is the current state of evidence around the aetiology of violence-fixated individuals (VFIs)?

For the purpose of this meeting, violence-fixated individuals (VFIs) were defined as: individuals with a fixation on violence, who are possibly showing intent to inflict violence, but who have no clear ideological motivations.

Summary of meeting notes

VFIs are each unique and complex. The functional relevance and combination of risk factors varies on a case-by-case basis, affecting the ability of systems like Prevent to identify cases.

Examples of risk factors include:

• early trauma
• dysfunctional family backgrounds
• personal grievances
• mental illness
• neurodevelopmental disorders
• online activities

Grievances are a significant risk factor in VFIs. Authorities should pay attention to the underlying interaction of factors behind grievances rather than the actual grievances. 

There is limited evidence on the effectiveness of interventions for VFIs, and most available evidence focuses on later-stage interventions. 

General approaches to violence reduction may offer insights for VFIs but have limitations. 

Improved identification of VFIs could be achieved through better data sharing and multi-agency collaborations that are adequately funded.

What evidence is there for understanding how VFIs evolve?

1. While many risk factors are present in VFIs, according to both clinical and academic evidence, each individual is unique. The functional relevance of risk factors and the combination of risk factors varies case by case (Tarnhall and others, 2023).

2. Risk factors include:

• disturbed and dysfunctional family backgrounds, including early trauma. These are common, but not universal
• there is a slight over-representation of mental health problems in violent offenders, including elevated levels of psychopathy. An FBI study of active shooters found that 25% of the sample had a mental illness diagnosis (Silver and others, 2018) but stressed that this should not be treated as a predictor of violence, given the prevalence of mental ill health
• neurodevelopmental disorders are particularly prevalent in violent offenders (Hughes, 2015; Billstedt and others, 2017), but vulnerability varies according to condition, symptoms and severity
• there is emerging evidence about a link between traumatic brain injuries and violence (Williams and others, 2018). It is possible that there may be ‘sleeper’ effects from a brain injury, that is the influence of an early brain injury is not seen until that part of the brain comes ‘online’ later in adulthood. This is poorly understood
• young offenders in particular do not have fully developed brains. There is emerging evidence that brain maturation could influence violent tendencies, which is particularly significant in the context of neurodevelopmental conditions or co-occurring mental health difficulties
• there are strong family or genetic factors, but these are difficult to disentangle. Large epidemiological studies have shown that violent behaviours have a genetic basis, with emotional dysregulation and how people understand social cues playing a role (Frisell and others, 2011)
• perpetrators of violence, especially young men, may follow a ‘cultural script’ in carrying out their actions (Mullen, 2003). A ‘blueprint’ for violent behaviour based on previous events such as the 1999 Columbine massacre (Macklin, 2019), which suggests method, instrument and ‘endgame’ (that is killing themselves)
• the rise of algorithms pushing content on social media can reinforce niche aspects of offenders’ identities (Grimmelmann, 2018). There is limited research on the impact of social media on VFIs, but it is clear that these platforms can amplify pre-existing risks and normalise intended behaviours

3. As well as risk factors, protective factors (such as loving attachments) should also be considered. It is often the loss of a key protective factor that hastens the radicalisation/mobilisation process (Pollard and others, 1999).

Grievance among VFIs

4. Grievance is an important risk factor in lone actor violence and therefore VFIs (Brooks and Barry-Walsh, 2022). Grievances can result from psychological and attachment needs not being met, challenges to identity or sense of belonging, perceived injustice and other reasons, in both physical and online spaces. Violence may result if an individual feels he or she has no other way to address the grievances apart from targeting individuals or groups. 

5. It is often easier to identify grievances after an act of violence has occurred. In preventative terms, understanding the risk factors underpinning grievances is more important than identifying the grievances themselves.

6. A nationally representative survey (Rottweiler and others, unpublished) found 3 significant risk factors in relation to grievance and radical attitudes:

• perceived victimhood: this may be felt across multiple relationships, more strongly and for longer than the norm
• anger rumination: this is a tendency to engage in repetitive thinking in response to distressing life events and is a particularly salient sign that grievances may escalate towards violence; there may be opportunities during the rumination phase for authorities to intervene
• low self-control: capacity for self-control is a key factor in explaining youth violence and criminal development and has been significantly associated with exposure to violent extremist settings, irrespective of ideology

7. Accessible online environments enable violence-fixated individuals, or those with pre-existing grievances, to find like-minded people with whom to air their grievances. They can use online peer groups to rationalise what they are experiencing. ‘Incels’ are a good example of where individuals who may have personal grievances against women find peers online who amplify those grievances (Sparks and others, 2022; Brace, 2023).

Identifying VFIs

8. Identification of VFIs could be improved through increased sharing of concerns about individuals from ’intimate bystanders‘ (Thomas and others, 2020; Eisenman and others, 2023) and from systemic, multi-agency collaborations. The lack of such collaborations, and failures in data sharing, are invariably lessons from serious case reviews.

9. The USA has, alongside counter-terrorism programmes, more sophisticated threat assessments of “targeted violence” from, for example, potential school shooters (Seaward and others, 2024; Cornell and others, 2025; Horgan and others, 2024).

10. There are various actuarial and structural professional judgement threat models available for risk assessing violent individuals, but there is uncertainty about their effectiveness (Fazel and others, 2022).

11. Data synthesis and sharing represents a more urgent need in identifying VFIs than data analysis.

12. Systemic, multi-agency collaborations are not feasible without greater investment.

Are there interventions which have been evaluated robustly at different stages in the evolution of VFIs?

13. General approaches to violence reduction, for example, provision of youth clubs (Fazel and others, 2024), have been reasonably well evaluated (such as Clemmow and others, 2024, Kim and others, 2017, Bonell and others, 2018). These evaluations point towards earlier interventions that focus on clusters of risk factors (rather than individual ones) being most effective.

14. There has been less robust or variable evaluation of more tailored programmes, such as for violence against women and girls (VAWG) or to prevent violent extremism. Evaluation of such programmes, such as Channel, is limited (Thornton and Bouhana, 2017).

15. The Prevent programme has identified VFIs in the past (such as Axel Rudakubana, Jake Davidson), but then lacks pathways to help them if they do not meet its criteria requiring an ideological component.

16. There is very little applicable evidence from evaluation of interventions to help VFIs. Available evidence is more focused on later-stage interventions, when individuals are receiving psychiatric care and when interventions are therefore bespoke for those individuals.

17. Insights from more general approaches to violence reduction may be applied to VFIs, but with some caveats:

• individual circumstances: some interventions will not be suitable for, say, those with neurodiverse conditions
• some programmes, such as family interventions to prevent domestic abuse, have been found, in some cases, to increase the risk of violence where coercive control exists, meaning data should be collected on unintended consequences
• the effectiveness of interventions may be context-specific, time-bound and time-limited
• there are a range of ethical considerations around interventions and data sharing efforts (such as Barker and others, 2025), including the importance of not stigmatising communities and individuals

Meeting participants

These participants attended the meeting:

• Angela McLean (GCSA, chair)
• Amy Orben (University of Cambridge)
• Brooke Rogers (KCL)
• Caroline Logan (University College London, formally University of Manchester)
• David Murphy (NHS)
• Lewys Brace (University of Exeter)
• Paul Gill (UCL)
• Paul Taylor (CSA Policing)
• Paul Thomas (University of Huddersfield)
• Seena Fazel (University of Oxford)
• Stan Gilmour (private consultant, ex-policing)

References

Barker R, Plackett R, Price A, Canvin K, Hartwell G and Bonell C (2024). Ethical challenges confronted in non-clinical, public health research with young people in England.

Billstedt E, Anckarsäter H, Wallinius M and Hofvander B (2017). Neurodevelopmental disorders in young violent offenders: Overlap and background characteristics.

Bonell C, Allen E, Warren E, McGowan J, Bevilacqua L, Jamal F, Legood R, Wiggins M, Opondo C, Mathiot A and Sturgess J (2018). Effects of the Learning Together intervention on bullying and aggression in English secondary schools (INCLUSIVE): a cluster randomised controlled trial.

Brace L (2023). Incels and the Incelosphere: An Overview of Current Research and Understanding. Centre for Research and Evidence on Security Threat (CREST).

Brooks N and Barry-Walsh J (2022). Understanding the role of grievance and fixation in lone actor violence.

Clemmow C, Fowler N, Seaward A and Gill P (2024). Risk of What and Why? Disaggregating Pathways to Extremist Behaviours in Individuals Susceptible to Violent Extremism.

Cornell DG, Kerere J, Konold T, Maeng J, Afolabi K, Huang F and Cowley D (2025). Referral rates for school threat assessment.

Eisenman DP, Weine S, Thomas P, Grossman M, Porter N, Shah ND, Polutnik Smith C, Brahmbhatt Z and Fernandes M. (2023). Obstacles and facilitators to intimate bystanders reporting violent extremism or targeted violence.

Fazel S, Burghart M, Fanshawe T, Gil SD, Monahan J and Yu R (2022). The predictive performance of criminal risk assessment tools used at sentencing: Systematic review of validation studies.

Fazel S, Burghart M, Wolf A, Whiting D and Yu R (2024). Effectiveness of violence prevention interventions: Umbrella review of research in the general population.

Frisell T, Lichtenstein P and Långström N (2011). Violent crime runs in families: a total population study of 12.5 million individuals.

Grimmelmann J (2018). The platform is the message.

Horgan J, Lorig C, Borum R, Allely CS and Herrenkohl TI (2024). Understanding and preventing violent extremism in school settings.

Hughes N (2015). Neurodisability in the youth justice system: recognising and responding to the criminalisation of neurodevelopmental impairment.

Kim BE, Gilman AB, Hill KG and Hawkins JD (2016). Examining protective factors against violence among high-risk youth: Findings from the Seattle Social Development Project.

Pollard JA, Hawkins JD and Arthur MW (1999). Risk and protection: Are both necessary to understand diverse behavioral outcomes in adolescence?

Rottweiler B, Clemmow C and Gill P (no date). The Genesis of Grievance: Examining the Formation of Grievance and their Impact Upon Violent Extremist Outcomes. Internal University College London report. Unpublished. 

Seaward A, Marchment Z and Gill P (2024). A directory of threat assessment models.

Silver J, Simons A and Craun S (2018). A study of the pre-attack behaviors of active shooters in the United States between 2000 and 2013.

Sparks B, Zidenberg AM and Olver ME (2022). Involuntary celibacy: A review of incel ideology and experiences with dating, rejection, and associated mental health and emotional sequelae.

Tärnhäll A, Björk J, Wallinius M, Gustafsson P and Hofvander B (2023). Offending trajectories in violent offenders: criminal history and early life risk factors.

Thomas P, Grossman M, Christmann K and Miah S (2020). Community reporting on violent extremism by “intimates”: emergent findings from international evidence.

Thornton A and Bouhana N (2019). Preventing radicalization in the UK: Expanding the knowledge-base on the Channel programme.

Williams WH, Chitsabesan P, Fazel S, McMillan T, Hughes N, Parsonage M and Tonks J (2018). Traumatic brain injury: a potential cause of violent crime?