Radicalization is the process by which a person comes to embrace increasingly extreme beliefs and, in some cases, a willingness to use or support violence in service of those beliefs. It is not a switch that flips. Research consistently frames it as a gradual shift driven by a combination of personal psychology, social bonds, perceived grievances, and the information environment a person inhabits. What makes the topic so difficult to pin down is that no single factor reliably predicts who will radicalize. Most people exposed to the same pressures never move toward extremism, and the ones who do follow strikingly varied paths to get there.
What Starts the Process
One of the strongest findings in radicalization research is that a blow to personal significance can act as an accelerant. Experiences that make someone feel humiliated, shamed, or stripped of status create an uncomfortable gap between how they want to see themselves and how they believe the world sees them. That gap generates a craving for certainty and meaning. Extremist ideologies, which tend to offer clear-cut answers and a path to restored dignity, become appealing precisely because they fill that void. Field surveys of political extremists imprisoned in the Philippines and Sri Lanka, combined with experiments on American samples, supported this connection between significance loss and increased openness to radical ideas.1PubMed. The road to extremism: Field and experimental evidence that significance loss-induced need for closure fosters radicalization
The psychological mechanism linking that personal crisis to extremism appears to run through something researchers call the need for cognitive closure: a strong preference for definitive answers over ambiguity. When people feel culturally threatened or personally destabilized, their desire for closure spikes. Studies across general populations in Denmark, Afghanistan, Pakistan, France, and an international sample, as well as a sample of former Mujahideen fighters, found that this heightened need for closure consistently mediated the link between perceived cultural threats and support for violent extremism.2PubMed Central. Cultural threat perceptions predict violent extremism via need for cognitive closure In plain terms, people who feel their world is under siege want answers that are simple, firm, and final, and extremist movements specialize in providing exactly that.
The Staircase Metaphor
One influential way of thinking about radicalization describes it as a narrowing staircase. At the ground floor are millions of people who feel deprived or unfairly treated. The vast majority stay there, venting frustration through ordinary channels or simply living with it. A smaller number, feeling they have no effective voice in society, climb to higher floors. At each step, the pool shrinks. People who keep ascending are encouraged by leaders or peers to direct their anger outward, toward an enemy group. Eventually, a tiny fraction reach the top of the staircase, where they have been socialized to view terrorist organizations as legitimate and members of the out-group as less than human.3PubMed. The staircase to terrorism: a psychological exploration
The staircase model is useful because it captures two things people often get wrong about radicalization. First, most dissatisfied people never radicalize; feeling aggrieved is the ground floor, not a conveyor belt. Second, the process is social and interactive at every stage. People do not simply think their way into extremism in isolation. They are recruited, mentored, and gradually embedded in networks that validate increasingly extreme views while cutting off alternative perspectives.
Grievances, Real and Perceived
A recurring question about radicalization is whether it grows from genuine injustice or from distorted perceptions. The honest answer is both, and the distinction matters less than you might expect. Research finds that both collective and individual feelings of relative deprivation correlate with radical attitudes, though measuring how those feelings translate into radical behavior remains difficult.4PubMed Central. Cognitive and behavioral radicalization: A systematic review of the putative risk and protective factors Perceptions of discrimination, racism, and systemic injustice at both the personal and group level can function as risk factors. In studies of U.S.-based radical offenders, group-based grievances predicted radical attitudes, which in turn predicted higher odds of violent rather than nonviolent extremism.5PubMed Central. Cognitive and behavioral radicalization: A systematic review of the putative risk and protective factors
This does not mean every person with a legitimate complaint is at risk. It means that the narrative of being wronged, whether rooted in real experiences of discrimination or amplified and distorted by propaganda, is one of the most reliable ingredients in the radicalization recipe. Extremist recruiters are skilled at locating people who already feel wronged and offering them both an explanation and a target.
Identity Fusion and Sacred Values
As a person moves deeper into an extremist milieu, something changes in how they relate to the group. In ordinary group membership, you might feel loyal to your community but still maintain a clear boundary between “who I am” and “what the group is.” In highly radicalized individuals, that boundary dissolves. Researchers describe this as identity fusion: a state where group identity taps directly into personal agency, so any attack on the group feels like a personal attack. This fusion helps explain the willingness to fight and even die for the cause, including in suicidal attacks.6PubMed Central. Exploring the Pathways Between Transformative Group Experiences and Identity Fusion
Closely related is the concept of sacred values: beliefs that a person holds as non-negotiable and beyond compromise. Neuroimaging work with supporters of an Al Qaeda-associated group found that when participants expressed willingness to fight and die for sacred values, brain regions normally involved in weighing costs and consequences showed reduced activity. When people defend sacred values, they appear to bypass the ordinary mental calculus of risk and reward. However, the same study found that exposure to peers who rated those sacred values differently could activate those cost-calculating brain regions again, suggesting that even deeply held convictions can be nudged by social context.7PubMed Central. Neuroimaging ‘will to fight’ for sacred values: an empirical case study with supporters of an Al Qaeda associate
That last finding is worth sitting with. It implies that radicalization, even at its most extreme, is not irreversible in the brain. The cognitive flexibility is still there; it just needs the right social signal to reactivate.
The Online Pipeline
The internet did not invent radicalization, but it has dramatically changed the speed and scale at which it can occur. One of the most contentious questions in recent years has been whether recommendation algorithms on platforms like YouTube actively push users toward more extreme content. An audit of YouTube’s recommendation system found that its suggestions do direct users toward ideologically biased and increasingly radical content, with right-leaning users experiencing this effect more strongly, both on homepages and in up-next recommendations.8arXiv. YouTube, The Great Radicalizer? Auditing and Mitigating Ideological Biases in YouTube Recommendations
Dedicated extremist forums tell a slightly more complicated story. Research on incel (involuntary celibate) communities, which combine intense misogyny and racism with glorification of violence, found that users already displayed high levels of anger and were using community-specific extremist vocabulary when they first joined the forums.9PubMed Central. The Angry Echo Chamber: A Study of Extremist and Emotional Language Changes in Incel Communities Over Time Initially, anger and use of incel-specific language increased after joining, but then flattened over time. The implication is that initial exposure to and embrace of the ideology often happens elsewhere on the internet before a person seeks out a dedicated community. The forum functions more as a reinforcement chamber than a recruitment tool.10Journal of Quantitative Description: Digital Media. A Dataset for The Study of Online Radicalization Through Incel Forum Archives
Gaming-adjacent platforms have emerged as another concern. Platforms like Discord, Twitch, and Steam were built for gaming communities but provide organizational infrastructure that extremist groups have exploited for recruitment and community building. Since the early days of video games, extremist groups have created, modified, and weaponized gaming content for propaganda purposes; the newer platforms have simply expanded the toolkit.11PubMed Central. Policing extremism on gaming-adjacent platforms: awful but lawful? The appeal is that these spaces feel casual, social, and unmonitored. A teenager hanging out in a Discord server built around a favorite game may encounter extremist messaging that feels organic rather than propagandistic.
Family Transmission
Radicalization does not always begin with the individual. A systematic review based on 53 studies found that intergenerational transmission of right-wing extremist, jihadist, and ethnonationalist beliefs does occur, though the research methods varied too much to allow a formal statistical synthesis.12Journal of Child and Family Studies. Inheriting Hatred? A Systematic Review of the Intergenerational Transmission of Extremist Ideologies Children growing up in households where extremist views are normalized absorb those views through the same mechanisms that transmit any parental belief: modeling, reinforcement, and the simple authority that parents hold over how young people interpret the world.
A separate large-scale systematic review covering over 148,000 adults and adolescents examined which family-level factors were associated with radicalization. Having extremist family members and experiencing family conflict were both linked to greater radicalization. Parental ethnic socialization, where parents strongly emphasized ethnic or cultural in-group identity, showed the strongest family-level association. On the protective side, higher family socioeconomic status, larger family size, and strong family commitment were all associated with lower radicalization, though the effect sizes were small.13PubMed Central. Is radicalization a family issue? A systematic review of family‐related risk and protective factors, consequences, and interventions against radicalization The takeaway is that family context can either insulate a person from radicalization or serve as its launching pad, depending on the dynamics at play.
The Mental Illness Misconception
After virtually every terrorist attack, public discussion turns to the perpetrator’s mental health. The assumption that radicalized individuals must be mentally ill is widespread but not well supported by the evidence. A systematic review found that the prevalence of psychiatric disorders among radicalized individuals ranged from about 6% to 41%, and among terrorists from roughly 3% to 49%, depending heavily on the study population and methodology. The review could not identify a significant overall association between radicalization, terrorism, and psychiatric disorders.14PubMed. Are radicalization and terrorism associated with psychiatric disorders? A systematic review
There is one important exception: lone-actor terrorists, those who plan and carry out attacks without direct organizational support, do show higher rates of psychiatric disorders compared to those who operate within groups. This makes intuitive sense. Group-based extremism involves social coordination, planning, and trust, activities that tend to filter out people with severe mental health challenges. Lone actors, by definition, lack that filtering process.
Autism spectrum disorder has received particular attention in this area. There is no evidence supporting an association between autism and extremism in the general population. However, researchers have noted that certain features of autism, such as rigid thinking patterns, intense focus on specific interests, and difficulty reading social cues, could create a context of vulnerability in certain environments.15PubMed. Autism spectrum disorder, extremism and risk assessment This is a sensitive distinction. It does not mean autistic people are at risk of becoming extremists. It means that in rare cases, specific traits may interact with other risk factors in ways that merit clinical awareness rather than blanket suspicion.
Why Different Ideologies Look Psychologically Similar
People tend to think of radicalization as ideology-specific: Islamist extremism involves one set of motivations, white supremacism another, far-left militant groups yet another. At the level of content, that is obviously true. But psychologically, the picture is surprisingly uniform. A study comparing political extremism and religious fundamentalism found that both were associated with a common worldview: the feeling that one supports a meaningful cause, intolerance of alternative ideologies, and a willingness to make personal sacrifices for one’s ideals.16Personality and Individual Differences. A comparison of extreme religious and political ideologies: Similar worldviews but different grievances Where they differed was in the specific grievances driving them, not in the underlying psychological architecture.
This finding has practical implications. It suggests that counter-radicalization strategies do not need to be rebuilt from scratch for every new ideological movement. The psychological vulnerabilities are largely the same: a need for meaning, a hunger for certainty, intolerance of ambiguity, and a willingness to sacrifice for the group. The content of the ideology is the paint; the psychological house it is applied to has a common blueprint.
The Evolutionary Angle
One way to understand why radicalization keeps recurring across cultures and centuries is to zoom out to an evolutionary timescale. The concept of parochial altruism proposes that two traits, cooperativeness toward the in-group and aggressiveness toward out-groups, may have coevolved in humans. Drawing on an idea originally proposed by Darwin, researchers have hypothesized that violent intergroup conflict played a substantial role in shaping human cooperativeness and altruism, with self-sacrificial behavior toward in-group members and hostility toward outsiders developing as a linked package.17PubMed Central. The evolutionary interplay of intergroup conflict and altruism in humans: a review of parochial altruism theory and prospects for its extension
If this hypothesis holds, then the psychological raw material for radicalization, the capacity to see one’s own group as sacred and outsiders as threats worth fighting, is not a bug in human psychology but a deeply embedded feature. That does not make radicalization inevitable or excusable. But it does help explain why appeals to in-group loyalty and out-group hostility are so effective across ideological lines, and why no society has managed to engineer radicalization out of existence entirely.
Getting Out and Staying Out
Researchers draw a useful distinction between disengagement and deradicalization. Disengagement means stopping the behavior, walking away from the group, ceasing to participate in violence. Deradicalization means changing the underlying beliefs. A person can disengage without deradicalizing, still holding extremist views but no longer acting on them, and the reverse is theoretically possible too, though far less common. Most intervention programs focus on disengagement as the more achievable first goal.
One popular approach involves using former extremists as mentors or intermediaries in prevention programs. The logic is appealing: who better to reach someone on the edge than someone who has been there? In practice, the evidence base for this is thin. A policy analysis focused on the use of “formers” in preventing and countering violent extremism found a notable lack of evidence supporting the prevailing assumptions about their effectiveness, while raising a range of ethical concerns about their involvement.18Journal for Deradicalization. The Ethics of Using Formers to Prevent and Counter Violent Extremism That does not mean former extremists have no role to play, but it does mean the field is operating more on intuition than on demonstrated results.
The neuroscience finding on sacred values mentioned earlier, that exposure to dissenting peers could reactivate the brain’s cost-benefit circuitry, hints at a mechanism that might underpin successful deradicalization: social context, not just argument, can shift even deeply held convictions. For people embedded in extremist networks, the social world has contracted to a point where the only voices they hear reinforce the ideology. Creating credible alternative social environments, where different perspectives are available without the feeling of being attacked, may be more effective than trying to win an argument with someone whose brain has effectively turned off the part that weighs arguments.