3.1 Existing categorisations and typologies

Various authors have suggested categorisations of different forms of radicalisation trying to decipher the phenomenon and to identify subgroups or profiles of interests within radicalised youths. These different categorisations are presented in Table 2. These categorisations are not comparable, because of the great variability of methodologies, approaches (criminological, sociological, anthropological) and populations from which they are developed. However, they portray the complexity of the profiles of these radicalised individuals. To detail one example: the usual categorisation used by law specialists to described terrorists, which distinguishes mainly 2 profiles (lone actor terrorist vs. group-based terrorist [Reference Corner and Gill16]), does not seem to fit radicalised young Europeans seen in prison contexts, where 3–4 profiles are proposed (see Table 2). Generally, these categorisations do not allow any correspondence with current classifications of mental conditions (e.g. DSM-5).

Table 2Existing categorizations and typologies for radicalised youth.

3.2 Individual risk factors

Psychiatric disorders are rare among radicalised youths. Individuals with a psychiatric condition represent a minority of the individuals involved in terrorist activities. Bazex and Bénézech found that only 10% of the individuals under the hand of justice for radicalisation presented a psychiatric disorder [Reference Bazex, Bénézech and Mensat27]. Besides, the average age of these individuals with psychiatric disorders is the highest (34 years) among the 4 categories proposed (see Table 2, [Reference Bazex, Bénézech and Mensat27]). For the rest of the individuals, they note various personality traits without a formal psychiatric diagnosis: anti-social, obsessional, and histrionic traits (especially in proselytic behaviours). Rolling corroborates this finding: she reports only 3 individuals with mental disorders among the 25 included in her study [Reference Rolling and Corduan28], knowing that this study is based on a young population (13–20 years) received in child psychiatry and not necessarily known to justice for radicalisation.

In contrast, several authors describe trait vulnerabilities or psychological vulnerabilities. Several types of psychological vulnerabilities have been highlighted as risk factors for youth radicalisation. A depressive dimension is often reported among radicalised youth, with a frequent feeling of despair that does not qualify as a major depressive episode (although formal psychiatric diagnosis is not available in most studies). Radical commitment can be thought of as a way to fight against this depressivity [Reference Rolling and Corduan28, Reference Benslama29]. For Benslama, the power of jihadist attraction comes from the ‘exalting promise’ that offers the adolescent a ‘soothing of the pain of living’ [Reference Benslama29]. Several authors hypothesise that radical ideology could often hide a suicidal intentionality. The notion of martyrdom is attractive because it gives meaning to one’s existing fragilities and suicidality. The issue of suicidal intentionality remains complex. While some authors insist that the promise of a ‘true’ life in the hereafter gives to death a saving status [Reference Khosrokhavar4, Reference Benslama29], others evoke pre-existing suicidal intentionality for certain subjects [Reference Bouzar and Martin30]. The relationship to death probably varies from one subject to another and is somehow reflected in the radical ideology that gives death a central place. This echoes Durkheim’s notion of ‘altruistic suicide’ by excess of integration [Reference Durkheim31]. In total, we lack empirical evidence to address the issue of suicidal intentionality among radicalised youths.

A history of addictive behaviour is often reported. Dependence on the radical group may act as a substitute product and replace the previous addiction: some subjects reported that the positive and rewarding effect of religious commitment allowed them to get rid of an addiction to a substance [Reference Bénézech and Estano7, Reference Ludot, Radjack and Moro32]. Radical commitment can also be conceptualised as a risky behaviour, with all the appeal it has for teenagers. For radicalised youths, going to Syria represents an initiatory quest [Reference Khosrokhavar4, Reference Bazex and Mensat33]. Addictive behaviour, risky behaviour and sensation seeking attitudes are common conduct disorders found among delinquent adolescents [Reference Thornton, Frick, Ray, Wall Myers, Steinberg and Cauffman34]. Radical commitment channels these behaviours by giving to the subject a firm framework within the group. Finally, early experiences of abandonment are found in most of the radicalised youth’s life trajectories [Reference Bazex and Mensat33]. A perceived fragile family structure and painful parental representations are vulnerability factors for youth radicalisation [Reference Rolling and Corduan28, Reference Bazex and Mensat33].

Adolescence per se is a risk factor for radicalisation. Adolescence is a phase of turbulence and reorganisation. For some adolescents, the inherent detachment from primary care givers and finding one's own identity bring a loss of security and sometimes a fear of loneliness and of being abandoned [Reference Rolling and Corduan28, Reference Ludot, Radjack and Moro32]. Belonging to a radical community conveys a sense of belonging, a sense of meaning and comfort [Reference Dhami and Murray35]. Based on the psychoanalysis of a radicalised subject and the content of jihadist propaganda, Leuzinger-Bohleber claims that the IS permits the satisfaction of pre-genital drives, which are rekindled in the early phases of adolescence [Reference Leuzinger-Bohleber36]. Violent actions advocated by radical groups unconsciously offer an enormous satisfaction of archaic drive-impulses and can be experienced as an omnipotent victory over the fear of death [Reference Leuzinger-Bohleber36]. Also, finding love objects outside of the family is another major issue of adolescence and is simplified by the organisation, which guarantees a reassuring marriage [Reference Leuzinger-Bohleber36]. Motivation towards marriage is found more frequently in young girls than in young men who are generally more attracted by the fascination exerted on them by armed combat [Reference Bouzar and Martin30, 37]. The changes in identifications during adolescence and the quest for an ideal open the way to radical ideologies [Reference Ludot, Radjack and Moro32]. Thus, the message sent by the IS may become attractive for some adolescents. The adolescent characteristics of the radicalisation process had not been put forward in the terrorist movements of the 1990s and 2000s. Bazex and Bénézech showed an age effect on the reason of justice control: subjects under judicial control for acts of apology or for acts of terrorism are much younger than those condemned for ordinary law crimes. On one hand, there are young people for whom radical engagement leads them to be under judicial control, and on the other side there are condemned adults who meet, by availability, radicalisation in prison. Individuals in prison can encounter radical commitment in a very variable way [Reference Bazex, Bénézech and Mensat27].

Personal uncertainty is another individual risk factor for radicalisation. Identity and identification issues and idealisation processes are central during adolescence. For several authors, these issues are at the core of the radicalisation process. The neo-identity associated with the radical group and ideology may give a new and reassuring meaning to the young person's experience [Reference Ludot, Radjack and Moro32]. Some add a dimension of imaginary affiliation to fallen Muslim origins that the subject glorifies again through his/her commitment [Reference Benslama29]. Radicalisation is viewed as an ‘act of recovery of identity’ or ‘recovery of lost dignity’ [Reference Khosrokhavar37]. Members identify with the leader’s power and prestige which compensate for the failures of their individual narcissism [Reference Bénézech and Estano7]. Theories of narcissism and grandiosity in groups highlighted the fact that the figure of the leader and the ideology becomes for the members of the group their ego ideal [Reference Kaës38]. This mechanism acts as a megalomaniac protection against anguish that reinforces the subjects’ fantasies of immortality [Reference Kaës38]. Middle-class youths can also experience this feeling of ‘victimisation’ by suffering from anonymity and non-belongingness. The latter could therefore also engage in jihadism because of a lack of identity firmly anchored in reality. The fact that adolescents from middle class and without family affiliation with Islam undergo radicalisation process underlines the importance of the adolescence process in this choice of radical engagement [Reference Ludot, Radjack and Moro32]. For Doosje, personal uncertainty is one of the three main determinants of a radical belief system, along with perceived injustice and perceived intergroup threat [Reference Doosje, Loseman and van den Bos39]. This finding is based on Hogg's ‘uncertainty-identity’ theory: the more individuals are uncertain in their environment, the more likely they are to identify themselves massively with groups [Reference Hogg40], and the more the properties of this group form a unit where individuals seem interchangeable, the more effectively this group reduces uncertainty [Reference Hogg, Meehan and Farquharson41].

Perceived injustice, or the feeling of injustice, is another determinant of radicalisation. It is cited in several studies, whatever the vocabulary or the methodology used: ‘Perceived injustice’ [Reference Doosje, Loseman and van den Bos39], ‘Perceived Oppression’ [Reference Moyano and Trujillo14], ‘Frustration’ [Reference Bazex, Bénézech and Mensat27], ‘Despair’, ‘Sense of Unworthiness' or ‘Perceived contempt’ [Reference Khosrokhavar37]. All these terms illustrate a deep malaise of the subject who tries to give sense to this ‘existential failure’. This ‘injustice’ is often put forward by the radicals themselves to justify their commitment and designate the culprits. Benslama also explains that this feeling of injustice, often provoked by personal experience, is then covered by radical ideology, giving a stronger value to its commitment [Reference Benslama29]. The link between perceived injustice and the reality of a socio-economic discrimination is developed below (see macro-envionnemental risk factors).

Several authors state the importance of a triggering event as a determining factor in acting out or at least reinforcing the radical commitment. The list of events includes the occurrence of a brutal trauma concerning a loved one (e.g., bereavement, illness, separation) [Reference Bouzar and Martin30, Reference Schuurman and Horgan42]; the occurrence of a love disappointment [Reference Bazex and Mensat33]; the viewing of a video of a battered woman who reminded him of his mother [Reference Schuurman and Horgan42]; or the viewing of a video that reactivated a profound suffering linked to family history [Reference Bazex and Mensat33]; and a recent experience of discrimination or the diffusion of violent and unsustainable videos [Reference Bouzar and Martin30].

Finally, several authors have described psychopathological mechanisms that are at stake during radicalisation and that reinforce radical engagement. The idea here is to explain the psychological mechanisms involved once the individual has started the process of radicalisation. First, projection is active: radical ideology offers the subject the possibility to project onto his enemies all the evil he feels inside and to soothe his guilt by what is designated as an act of purification [Reference Dayan43]. This operation may be accompanied by a paranoia mechanism and a use of splitting of the ego. This paranoia mechanism acts as a defense mechanism and does not account for a psychiatric pathology or personality organisation [Reference Bénézech and Estano7, Reference Bazex, Bénézech and Mensat27, Reference Benslama29]. The splitting process is highlighted by several authors and explains how these individuals can set aside the moral values they had in the past [Reference Zagury15, Reference Bouzar and Martin30, Reference Dayan43]. Various authors have reported that obsessive compulsive habits are also frequent among radicalised youth [29, Reference Bouzar and Martin30]. These symptoms often have a function of ‘purification’, such as found in radical ideology or the practice of a rigorist religion. Radical engagement may soothe pre-existing anxiety symptoms by offering a reassuring framework. For Khosrokhavar and Ludot, today’s European jihadists of the middle classes suffer from a lack of authority and are in need of an authoritarian normativity that shows them rules to follow [Reference Ludot, Radjack and Moro32, Reference Khosrokhavar37]. These elements show the importance of the radical group that welcomes the candidates to radicalisation, and they suggest how the influence of the micro-environment is decisive in the process of radicalisation.

3.3 Micro-environmental risk factors (family and proximal environment)

Fragility and failure of the family group is a risk factor for radicalisation. Studies focusing on the families of radicalised youths often portray deficiencies, traumas and/or distress during the childhood and adolescence of these subjects [4, Reference Rolling and Corduan28, Reference Bazex and Mensat33]. In Bazex and Bénézech’s study, which included 112 individuals under judicial control for radicalisation, they report a large proportion of individuals who experienced ‘a childhood marked by significant parental difficulties, a father often absent and a mother whose integrity is often attacked (depression, suicide attempt, disability)’ [Reference Bazex, Bénézech and Mensat27]. In their view, this contributes to a major inconsistency in identificatory processes (in other words, identity uncertainty). Among the members of the Hofstadgroup, a Dutch terrorist organisation, Schuurman found that one of the risk factors that makes the radical group particularly effective is the isolation of the subject and the absence of countervailing opinions in the family [Reference Schuurman and Horgan42]. The lack of a corrective answer to the subject’s radical positions was also reported by Van San et al among 16 Islamists and extreme right adolescents who exposed on the internet their radical ideas [Reference Van San, Sieckelinck and de Winter44]. He described permissive parents with little response to their child's radical opinions.

Friendship or admiration towards a member of the radical group is often reported. This seems obvious in studies focusing on the most-extremist cases seen in judicial contexts. Most of the radicalised individuals had a role model, an inspirational figure in the radical group who initiated the process of radicalisation. Schuurman highlighted this finding for individuals among the ‘Hofstadgroup’ in Holland, and Bazex confirmed it among French radicalised youths returning from Syria [Reference Bazex and Mensat33, Reference Schuurman and Horgan42].

Several authors have found similarities between the techniques of radical jihadist groups and sectarian community methods to recruit new members. Based on his knowledge of sectarian methods, Dayan described common mechanisms such as narcissistic gratification, moral debt, real or imagined threats and the progressive setting aside of the family/friendship network [Reference Dayan43]. Rolling described two phases in the radicalisation process of the youth encountered in child psychiatry units: a first phase during which the radical commitment has a soothing function on psychic suffering and a second phase during which the ideological indoctrination leads to the self-effacement of the subject in favour of the group [Reference Rolling and Corduan28]. Bouzar studied the way the youth was enlisted on the internet and explained that the ‘recruiters’ of radical groups adapt the propaganda media to the ‘sensitivity’ of each subject [30, Reference Bouzar45]. Youths are subject to psychological pressure from the recruiters to adopt the radical beliefs and to break with friends and family [Reference Bouzar46]. Bazex & Bénézech highlighted one category of radicalised individuals who have a charismatic character associated with proselytic and manipulative behaviours: ‘the proselytic networker’ [Reference Bazex, Bénézech and Mensat27]. Radicalised individuals with other profiles (e.g., ‘ambitious offenders’; ‘people in a precarious situation’) may be vulnerable to indoctrination by ‘proselytic networkers’. Khosrokhavar also reported this form of relational dissymmetry between a charismatic individual who exerts an influence on more-fragile individuals [Reference Khosrokhavar4].

The radical group instigates the subject’s dehumanisation. This is a key process to understanding how mainly normal individuals can engage in terror activities. For Bazex & Bénézech, the radical group and ideology help to legitimise a pre-existing violence in the subject [Reference Bazex, Bénézech and Mensat27]. The aggressive and destructive instincts that dominate the fantasy life of these individuals find a way of justification and ideal expression in projection towards the outside. Dayan states that there is a ‘narcissistic contract’ between the individual and the group and that this contract is crucial: the group offers a place and a role to the subject, and in exchange, he must repeat the same statements and ensure the permanence of this transmission [Reference Dayan43]. Khosrokhavar studied the case of young Europeans who wanted to go to Syria [Reference Khosrokhavar4]. He explained that this desire was more often driven by humanitarian concerns than by violent radicalism. He described these young people as ‘pre-radicalised’ and explained that once within the group, they learn to become insensitive to the suffering of others and becoming ‘real jihadists’. Bouzar identifies four steps used by recruiters in order to effect the ‘dehumanisation’ of the subjects: (i) isolation of the individual from his environment; (ii) destruction of the individual as a unique personality for the benefit of the group; (iii) adherence to the IS ideology; (iv) dehumanisation of the subject and of his future victims [Reference Bouzar46]. These steps are consistent with Bandura's work on ‘moral agency’ and dehumanisation: ‘The moral disengagement may center on the cognitive restructuring of inhumane conduct into a benign or worthy one by moral justification, sanitising language, and advantageous comparison; disavowal of a sense of personal agency by diffusion or displacement of responsibility; disregarding or minimising the injurious effects of one's actions; and attribution of blame to, and dehumanisation of, those who are victimised’ [Reference Bandura47]. These mechanisms are also described by Zagury [Reference Zagury15] and Bouzar [Reference Bouzar46] when they explore the link between the ‘recruiters’ and the youth exposed to radical theories.

3.4 Macro-environmental risk factors (cultural and societal environment)

The evidence of macro-environmental factors is more complex. Social polarisation is one such risk factor. Unequal or discriminatory socio-economic conditions are highlighted by many authors as contributing to the phenomenon of radicalisation. Khosrokhavar explains that the ‘ghettoized existences’ associated with the sense of dehumanisation subjects feel through social disregard lead them to the desperate conviction of being in a deadlock [Reference Khosrokhavar4]. When this conviction is not associated with an ideology, these young people may take the path of delinquency. If this conviction finds religious ideological support, the hatred of society is sacralised and the goal becomes to ‘save Islam’. Khosrokhavar noted that most French people who have committed terrorist acts were born in disorganised families, had grievances against society, had a feeling of social injustice and a denial of identity (feeling neither French nor from their country of origin) [Reference Khosrokhavar4]. Moyano studied Muslim and Christian high school students in Spain and showed a significant polarisation between the two groups when they came from the same neighbourhood [Reference Moyano and Trujillo14]. When asked what defines them best, Muslims mostly chose identification with religion (when they could choose Spain or their country of origin), while Christians chose their country. Similarly, French authors reported that young people who have returned from Syria or young people under the grip of justice for radicalisation often had difficulties in social integration, particularly at school, with a history of exclusion [Reference Bazex, Bénézech and Mensat27, Reference Bazex and Mensat33].

Doosje et al identified perceived group threat as a major contributor to maintaining a radical belief system [Reference Doosje, Loseman and van den Bos39]. The perceived group threat may take three different forms: symbolic threat, realistic threat, and intergroup anxiety. Symbolic threat refers to threat to the Islamic culture. Realistic threat refers to threat to the economic status of one’s group. Intergroup anxiety is defined as the fear one can experience when one has to interact with a person from another group. Once again, these results underline the importance of group polarisation and its consequences for feelings of oppression or perceived injustice. Bhui supports the use of a public health approach to understand and prevent violent radicalisation, arguing that anti-terrorism approaches based on the judicial system or on criminology do not prevent radicalisation, since they intervene after the act [Reference Bhui, Hicks, Lashley and Jones48]. These latter actions would even tend to stigmatise Muslim communities and undermine social cohesion, while better social cohesion is associated with a reduction of violence, better public health, and a more equal and just society. To support this view, Bhui et al. studied vulnerability factors and resistance factors to violent radicalisation in a cross-sectional survey of a representative population sample of men and women aged 18–45 of Muslim heritage in two English cities [Reference Bhui, Warfa and Jones49, Reference Bhui, Everitt and Jones50]. They showed that sympathy for violent protest and terrorist acts was more likely to be articulated by those under 20, by those in full time education rather than employment, by those born in the UK, by those speaking English at home, and by high earners (>£75,000 a year). Anxiety and depressive symptoms, adverse life events and socio-political attitudes showed no associations. On the other hand, resistance to radicalisation measured by condemnation of violent protest and terrorism was associated with a larger number of social contacts, less social capital, unavailability for work due to housekeeping or disability, and not being born in the UK [Reference Bhui, Warfa and Jones49, Reference Bhui, Everitt and Jones50]. Interestingly, here again, sympathy was higher among the youngest individuals and those born in the UK rather than immigrants [Reference Bhui, Warfa and Jones49, Reference Bhui, Everitt and Jones50]. In another cross-sectional study in the UK, Coid et al showed that men at risk of depression may experience protection from strong cultural or religious identity [Reference Coid, Bhui, MacManus, Kallis, Bebbington and Ullrich51]. These results seem paradoxical and highlight the importance of a consideration at all three levels (macro, micro and individual): some factors can act either on the side of protection or of vulnerability to a radical system.

The link between religious fundamentalism and radicalisation is complex. Many authors mention the importance of religion in the process of radicalisation. Moyano reported that Muslim religious identity was stronger than Christian identity in Spain [Reference Moyano and Trujillo14]. Dayan noted recent claims of religious identity among French youths [Reference Dayan43]. Coid showed that religious affiliation and practice were protective against antisocial behaviours but could determine targets of violence following radicalisation [Reference Coid, Bhui, MacManus, Kallis, Bebbington and Ullrich51]. Benslama emphasised the importance of the history of the Arab world and Islam in explaining the discourses of Islamic fundamentalists and the creation of a new identity figure that he called the ‘super-Muslim’ [Reference Benslama29]. According to Benslama, there is a ‘constraint under which a Muslim is led to outbid the Muslim he is by the representation of a Muslim who must be even more Muslim’. The subject is encouraged to identify himself with ‘the perfect Muslim, the Prophet and the ancestor’, according to the belief that ‘the good has already happened, the promise has been fulfilled, there is nothing left to do but to return to the past, while waiting for the end of the world, or better: to hasten it’ [Reference Benslama29]. Benslama illustrates how religious fundamentalism provides an identity figure in which youths can find a totalising meaning. It is crucial to differentiate Muslim religion from radical Islamist ideology. Some political scientists have argued that for ISIS, religion is more a way to justify their actions, rather than a cause to defend, unlike other forms of religious fundamentalism [Reference Roy52].

The geopolitical context also has a major influence. Several authors have noted that the proclamation of a caliphate by the IS added legitimacy to this radical ideology [Reference Khosrokhavar4, Reference Benslama29, Reference Bouzar and Martin30]. Contrary to the Al-Qaeda network, the IS is anchored in a territory, and its propaganda describes the territory as an idyllic place, a community utopia where the Muslim ‘brothers’ are most welcome. Different terms have emerged, conveying the message of ideological propaganda associated with this territory: the ‘Hijra’ (emigration of a Muslim from a non-Muslim country to a Muslim country), the ‘Land of Al-Sham’ (literally ‘land on the left-hand’, referring to a Caliphate province in the region of Syria) or ‘Ummah’ (world community of Muslims). Geopolitical events undoubtedly influence the phenomenon of radicalisation whether in its rise in 2014 during the proclamation of the caliphate or during its decrease in intensity since the IS was defeated in Syria and Iraq in 2017.

Societal changes may affect the radicalisation process. According to various authors, the mutations of modern societies may favour the appearance of the phenomenon of radicalisation. Khosrokhavar uses Durkheim's term ‘Anomie’ [Reference Durkheim53] to explain that the dissolution of the moral, religious or civic values of modern societies leads to a feeling of irresolution that makes youths more inclined to turn towards religious fundamentalisms and possibly towards radical ideologies [Reference Khosrokhavar4]. These considerations are in line with Zygmunt Bauman's more modern concept of ‘liquid modernity’, according to which the individual is integrated only by his act of consumption [Reference Bauman54]. Social status, identity or success are defined in terms of individual choices and can fluctuate rapidly depending on socio-economic requirements. This fluid modernity brings at the same time freedom but also uncertainty and insecurity. Khosrokhavar [Reference Khosrokhavar37] adds that among these young people, who suffer from the ‘deliquescence of politics’ and the ‘dispersion of authority between several parental bodies’, radical Islamism offers tangible and reassuring norms carried by an unequivocal authority. Benslama also discusses this change in the social model [Reference Benslama29]. He explains that the traditional model, in which filiation defines the identity of the subject, is endangered in favour of a new social model where each subject needs to forge his own place and identity, with all the anxiety it can generate. Some individuals have the resources to face this challenge, but those who fail to do so may be tempted by the solutions offered by the radical ideologies by attacking the society that has placed them in this insecure situation. Radicalised individuals believe that radical ideology, by destroying the existing society, offers them the possibility of a promising new societal model. Also, the society is believed to convey all kinds of conspiracies by forces that stole power from the people (e.g., financial power), and IS recruiters use conspiracy theories to destroy the world of candidates to radicalisation to make them commit to a new one [Reference Bouzar and Martin30, Reference Bouzar45].