Mechanisms of Political Radicalization: Pathways
CLARK McCAULEY AND SOPHIA MOSKALENKO
Psychology Department, Bryn Mawr College, Bryn Mawr,
This article conceptualizes political radicalization as a dimension of increasing
extremity of beliefs, feelings, and behaviors in support of intergroup conflict and violence. Across individuals, groups, and mass publics, twelve mechanisms of radicalization are distinguished. For ten of these mechanisms, radicalization occurs in a
context of group identification and reaction to perceived threat to the ingroup.
The variety and strength of reactive mechanisms point to the need to understand
radicalizationâ€”including the extremes of terrorismâ€”as emerging more from the
dynamics of intergroup conflict than from the vicissitudes of individual psychology.
Keywords pyramid model, radicalization, terrorism
In this article we describe mechanisms of radicalization relevant to understanding the
origins of terrorism. We must immediately acknowledge that the idea of mechanism
is somewhat different in different domains of social science, sometimes with conflicting definitions used within a single discipline.1,2 Here we use mechanism in the general sense traditionally employed in Psychology: â€˜â€˜the means or manner in which
something is accomplished. Thus, the mechanism of vision includes the physical
stimulus and the physiological and neural processes involved.â€™â€™3
Clark McCauley is Professor of Psychology and a director of the Solomon Asch Center
for Study of Ethnopolitical Conflict at Bryn Mawr College, and a co-director of the National
Consortium for Study of Terrorism and Responses to Terrorism (NC-START). Sophia
Moskalenko received her Ph.D. in Social Psychology from the University of Pennsylvania
in 2004. She is a postdoctoral fellow at the Department of Homeland Security and a research
fellow at the National Consortium for Study of Terrorism and Responses to Terrorism
This research was supported by the United States Department of Homeland Security
through the National Consortium for the Study of Terrorism and Responses to Terrorism
(START), grant number N00140510629. However, any opinions, findings, and conclusions
or recommendations in this document are those of the authors and do not necessarily reflect
views of the U.S. Department of Homeland Security. The authors are grateful to Gary LaFree
and Tony Marsella for comments and suggestions in response to draft versions of this paper,
and thank three anonymous reviewers for numerous helpful suggestions.
Address correspondence to Clark McCauley, Solomon Asch Center for Study of Ethnopolitical Conflict, Bryn Mawr College, 101 N. Merion Ave., Bryn Mawr, PA 19010. E-mail:
Copyright # Taylor & Francis Group, LLC
ISSN: 0954-6553 print=1556-1836 online
Terrorism and Political Violence, 20:415â€“433, 2008
Functionally, political radicalization is increased preparation for and commitment to intergroup conflict. Descriptively, radicalization means change in beliefs,
feelings, and behaviors in directions that increasingly justify intergroup violence
and demand sacrifice in defense of the ingroup. How does this happen? How do
individuals, groups, and mass publics move toward conflict and violence?
This question applies as well to state preparation for conflict as to non-state preparation for conflict. A state and its citizens are radicalized in the run-up to interstate
conflicts and war, and, as evident in the U.S. after the attacks of September 11, 2001,
in state response to terrorism as well. But common discourse about radicalization
focuses on non-state groups that represent a challenge or threat to the state. Similarly,
terrorism as a means of political control is predominantly government work,4 but
common discourse associates terrorism with the actions of non-state groups. In this
paper, we focus on the common usage in which radicalization refers to increasing
extremity of non-state challenges to state authority. We aim to show, however,
how state action can contribute to radicalization of non-state groups.
Radicalization in the Pyramid Model
Individual and Mass Radicalization
There are many possible meanings of radicalization, but most of the relevant distinctions can be represented with the usual social psychological distinctions among
belief, feeling, and behavior. Of course it is radicalization of behavior that is of
greatest practical concern. In a political context this means increasing time, money,
risk-taking, and violence in support of a political cause. As every political cause is
associated with a particular group that cares about this cause, we may equally
say that behavioral radicalization means increasing time, money, risk-taking, and
violence in support of a political group.
If at a given point in time we compare those who are more and less behaviorally
committed, we are likely to find differences in both beliefs and feelings. Social movement activists are likely to share more than non-activists the beliefs or â€˜â€˜framesâ€™â€™ that
the movement uses to summarize and convey its mission.5 Anti-poverty activists, for
instance, tend to see different causes of poverty than non-activists.6 Radicalization of
many kinds may be associated with a syndrome of beliefs about the current situation
and its history:7 We are a special or chosen group (superiority) who have been
unfairly treated and betrayed (injustice), no one else cares about us or will help us
(distrust), and the situation is direâ€”our group and our cause are in danger of extinction (vulnerability).
Similarly those who do more are likely to have different and stronger feelings
about the conflict than those who do less.8,9 Activists are likely to feel more sadness
and humiliation with group failures, more joy and pride with group success, more
anger and fear at the perfidy or violence of the enemies of their cause.
These feelings are the expression of group identification: caring about what happens to the group, especially in relations with other groups.10 Group identification
can even lead to feelings of guilt about wrongdoing perpetrated by others, if the
others are members of the group identified with.11 The human capacity to care about
large and impersonal collectivities as if they were an extended family is the foundation of mass politics, and the pre-requisite for national, ethnic, and religious group
416 C. McCauley and S. Moskalenko
Because terrorists are few in relation to all those who share their beliefs and
feelings, the terrorists may be thought of as the apex of a pyramid.14 The base of
the pyramid is composed of all who sympathize with the goals the terrorists say
they are fighting for. In Northern Ireland, for instance, the base of the pyramid of
support for the IRA was all those who agreed â€˜â€˜Brits out.â€™â€™ In the U.S., the base
of the pyramid of support for anti-government action is the forty percent of
Americans who agree that â€˜â€˜The federal government has become so large and
powerful that it poses an immediate threat to the rights and freedoms of ordinary
From base to apex, higher levels of the pyramid are associated with decreased
numbers but increased radicalization of beliefs, feelings, and behaviors. Thus one
way of thinking about radicalization is that it is the gradient that distinguishes
terrorists from their base of sympathizers. How do individuals move from the base
to the extremes of terrorist violence at the apex?
Radicalization in Groups
Economists and political scientists using a rational-choice framework are fond of
pointing out that individuals should be reluctant to commit real resources of time,
money, and risk-taking to advance the cause of a large group. The benefits of
advancing the group are available to all group members, whereas the costs are
borne by the activists. Thus the rational choice for an individual who cares about
a group cause is to do nothing, let other individuals pay the costs, and benefit from
any advance for the group as a free-rider.16
The classic answer to the problem of mobilizing individuals for social action is
some kind of coercion, that is, punishment for free-riding. Coercion may come from
law or government regulation (if free-riders can be accurately identified), from individual morality (internal norms), or from informal face-to-face sanctions (small
group norms). Particularly in a small group, personal morality and group norms
can be difficult to separate, because individual morality is usually anchored in some
kind of group consensus. And in a small face-to-face group where each member and
each memberâ€™s behavior is known to others, social rewards for participation and
social punishments for free-riding can make behavioral commitment rational after
all. When groups can be linked through common members or common leaders into
a larger multi-group organization, social action becomes possible on a larger scale.
Thus radicalization and terrorism are made possible by bringing individuals into
small groups. Sometimes these groups are linked into a larger organization, but not
always. The small group is necessary for action, but the organization is not. The original Al Qaeda was an organization of groups or cells, but today the groups are
mostly on their own and disconnected from any larger organization. The Madrid
bombers were apparently more a self-organizing small group than a cell embedded
in Al Qaeda.
Radicalization of Individuals, Groups, and Masses
As indicated in the preceding discussion, radicalization can occur at different levels.
Individuals are radicalized by personal grievances and by identity-group grievances
as conveyed by mass media, rumor, or the testimony of others. Individuals are also
Mechanisms of Radicalization 417
radicalized as members of small face-to-face groups. Political groups and mass
publics are radicalized in conflict with states and with other political groups. Each
of these levels requires separate attention. Table 1 identifies the twelve mechanisms
at three levels that we will now describe.
1. Individual Radicalization by Personal Victimization
This is a path much cited in explanations of suicide terrorists. Chechen Black
Widows are described as seeking revenge against Russians for their own experience
of rape or for the deaths of their menfolk.17 Tamil Tigers of the suicide brigades
called â€˜â€˜Black Tigersâ€™â€™ are often described as survivors of Sinhalese atrocities.
Accounts of Palestinian suicide terrorists often cite revenge for IDF attacks on
neighbors or loved ones as a motive for self-sacrifice.
The importance of personal grievance as a motive for terrorism goes back at least
as far as Russian terrorists of the late 1800s. Thus Andrei Zhelyabov, a leader of terrorist organization Peopleâ€™s Will and a mastermind of a number of political assassinations, including the coordinated bombs that killed Czar Alexander II, sought out
terrorist activity in a pledge to revenge the many wrongs by the monarchist regime
he experienced firsthand.18 The rape of his favorite aunt by their landmaster, ignored
by local police; his dismissal from university without right to reapply for participating
in an innocent protest against arbitrary grading practices; and finally, a four-month
jail sentence for sending a friendly note to an imprisoned friendâ€”these grievances
shaped and hardened Zhelyabovâ€™s resolve to use violence against the ruling elite.
Data are hard to come by on how many terrorists, or how many suicide terrorists, have a personal history of victimization that might explain their sacrifice. Of
course there may be individuals with such a history who nevertheless would not have
moved to violence without seeing their victimization joined to the victimization of
their ethnic or national group. That is, the percentage with a history of personal
victimization is an upper bound of the power of a personal-revenge explanation,
rather than a reliable estimate of this power. A social psychological view would be
Table 1. Pathways to violence: Mechanisms of political radicalization at individual,
group, and mass-public levels
Level of radicalization Mechanism
1. Personal victimization
Individual 2. Political grievance
3. Joining a radical groupâ€”the slippery slope
4. Joining a radical groupâ€”the power of love
5. Extremity shift in like-minded groups
Group 6. Extreme cohesion under isolation and threat
7. Competition for the same base of support
8. Competition with state powerâ€”condensation
9. Within-group competitionâ€”fissioning
Mass 10. Jujitsu politics
418 C. McCauley and S. Moskalenko
that personal grievance is unlikely to account for group sacrifice unless the personal
is framed and interpreted as representative of group grievance.
2. Individual Radicalization by Political Grievance
Sometimes an individual is moved to individual radical action and violence in
response to political trends or events. Ted Kaczynski, the Unabomber, is one
example. Over eighteen years, Kaczynski emerged occasionally from his wilderness
cabin to send letter bombs to people representing the technological progress he
feared and detested.
Another example is Buford Furrow, who turned himself in to police in August
1999 after wounding five at a Jewish Community Center and later killing a Filipino
postman. He seems to have been a devotee of white supremacist groups but acted
alone in planning and carrying out these attacks.
Similarly, John Allen Muhammad, with his proteÂ´geÂ´ Lee Boyd Malvo, killed ten
people in the Washington area in 47 days of sniper attacks in September and October
2002. Muhammad, a convert to Islam and black separatism, was attempting to
extort ten million dollars with which to found a pure black community in Canada.19
Muhammad has not been forthcoming about his motivation, but it appears he identified with what he perceived to be the victimization of black people in the U.S.
Cases of individual radicalization to political violence, that is, cases in which the
individual acts alone rather than as part of a group, are relatively rare. In such cases,
the individual is likely to have some association with a larger intellectual movementâ€”as Kaczynski related to a larger movement of survivalists, as Furrow associated
with white supremacists, and as Muhammad participated for a period in the Nation
More than in any other category of radicalization, there is a probability of some
degree of psychopathology. Psychiatric testimony at his trial indicted that Kaczynski
suffered from paranoid schizophrenia. The prosecution did not seek the death penalty for Furrow because he had a history of inpatient hospital treatment for mental
disorder. Groups of radicals, especially those who get as far as terrorism, are unlikely
to recruit or tolerate the unreliability that goes with psychopathology. Individualist
radicals can be responding, at least in part, to their private demons.
An interesting example of the difficulty of separating personal and group
grievance is Matt Hale, who in 1998 was the leader of a white supremacist group.
Hale graduated from law school, passed the bar exam, was hired by a law firm,
but lost his job when the Illinois Bar denied his law license on the basis of racism.
In 2005, Hale was sentenced to prison for soliciting the murder of federal judge Joan
Lefkow. The personal and political are so closely intertwined in this case that it is
impossible to say what Hale would have done had he been granted his law license.
3. Individual Radicalization in Joining a Radical Groupâ€”The Slippery Slope
As just noted, it is rare that an individual moves from sympathizer to activist by suddenly undertaking some major risk or sacrifice. Typically an individualâ€™s progress
into a terrorist group is slow and gradual, with many smaller tests before being
trusted in more important missions, and with many non-violent tasks before being
asked to use gun or bomb (for Red Army Faction and Basque ETA recruits, see note
20, p. 237; for IRA recruits see note 21).
Mechanisms of Radicalization 419
Of course there are occasional examples of an individual moving from sympathy
to extreme violence in a single giant step. Wafa Idriss, the first female Palestinian
suicide bomber, seems to have carried out her mission within two weeks of deciding
to become a suicide bomber. Although it is beyond the scope of the present paper to
examine this question systematically, we believe that examples of giant-step transition to violence are notable precisely because they are relatively uncommon.
A vivid example of gradual radicalization comes from Della Porta,22 who quotes an
Italian militant as follows: â€˜â€˜A choice [made] in cold blood, such as â€˜now I will become a
terrorist,â€™ [did] not exist. It was a step-by-step evolution, which passed through a kind of
human relation that I had with Guido, and with the people I worked with.â€™â€™
The power of step-by-step self-persuasion through oneâ€™s own behavior is well
studied in social psychology. Hundreds of experiments have shown a strong tendency for self-justification after an individual does something stupid or sleazy.
An individual who is sucked into saying a dull experiment is fun, or into writing
an essay in favor of a cause the individual disagrees with, is likely to find reasons
to justify the behavior: the experiment wasnâ€™t half bad, keeping Communists from
speaking on campus is a good idea. Dissonance theory23 understands this tendency
as an effort to reduce the inconsistency between positive self-image and bad behavior. In other words, it is easier to find reasons for what we do than to do what we
find reason for.
Perhaps the most striking example of the power of self-radicalization is found in
one of the experimental variations introduced by Milgram24 in his famous studies of
obedience. In the basic paradigm, normal individuals who draw the role of teacher in
a psychology experiment will give high levels of shock to a protesting â€˜â€˜victimâ€™â€™ (actually an accomplice of the experimenter) who drew the role of learner. Complete obedience requires the teacher to raise the shock administered for mistakes from 15 to
450 volts in 15-volt increments. About 60% of teachers are completely obedient.
Less well known is the variation in which it is not the experimenter who comes
up with the idea of raising the shock level with each mistake. In this variation, a â€˜â€˜coteacherâ€™â€™ (another accomplice of the experimenter) asks and grades the questions,
while the naÄ±Â¨ve teacher gives the shocks. The experimenter, summoned away for a
â€˜â€˜phone call,â€™â€™ is no longer in the room when the â€˜â€˜co-teacherâ€™â€™ comes up with the idea
of raising the shock level with each mistake. Despite the absence of the experimenter
and his authority, 20% of teachers progress to administering 450 volts.
The dissonance explanation of the 20% who go all the way is that each shock
becomes a reason to give the next shock. The closely graded shock levels represent
a kind of slippery slope in which refusing to give the next shock requires recognizing
that there was something wrong with giving the last shock. If 300 volts was ok, how
can 315 volts be wrong? But if 315 volts is wrong, how can 300 volts be right?
In Milgramâ€™s studies, the dependent variable is radicalization in behavior, not in
thoughts or feelings. The latter were not measured, and there is no way of knowing
whether increasing shock levels were associated with changes in perception of and
attitude toward the victim.
In another famous study, Zimbardo25 was able to demonstrate radicalization in
behavior of one group of participants (playing roles of prison guards) toward
another group (playing the role of prisoners). Psychologically stable male student
volunteers were randomly assigned to act as either a guard or a prisoner in a simulated prison environment. Left to their own devices, over the course of just a few
days, the guards gradually escalated their abuse (in the form of humiliation and
420 C. McCauley and S. Moskalenko
arbitrary punishment) toward the prisoners to the degree that Zimbardo was forced
to terminate the experiment.
As in Milgramâ€™s experiment, feelings and beliefs were not measured during the
Prison Experiment. But there is an obvious progression toward more dehumanizing treatment of the prisoners, starting from making them do push-ups, moving on
to making them eat filthy food, and ending with forcing them to act out sexually
suggestive plays. In post-experiment interviews, one of the â€˜â€˜guardsâ€™â€™ suggested that
his increasingly cruel treatment of the â€˜â€˜prisonersâ€™â€™ was the result of his curiosity as
to how much the â€˜â€˜prisonersâ€™â€™ would let him get away with. For this guard, the
fact that he went too far is the fault of the â€˜â€˜prisonersâ€™â€™ who did not stand up
There is then a pattern of slowly increasing radical behaviorâ€”behavior that
harms othersâ€”in both the Milgram experiments and Zimbardoâ€™s prison experiment.
In dissonance experiments and in Zimbardoâ€™s post-experimental inquiry, we see the
power of self-persuasion in justifying oneâ€™s own behavior. Self-radicalization is a
slippery slope of increasingly extreme behaviors, with increasingly extreme reasons
and justifications icing the slope.
4. Individual Radicalization in Joining a Radical Groupâ€”The Power of Love
This is the path to radicalization that has received most attention in recent theorizing
about terrorism.26 Individuals are recruited to a terrorist group via personal connections with existing terrorists. No terrorist wants to try to recruit someone who might
betray the terrorists to the authorities. In practice, this means recruiting from the
network of friends, lovers, and family.
Trust may determine the network within which radicals and terrorists recruit,
but love often determines who will join. The pull of romantic and comradely love
can be as strong as politics in moving individuals into an underground group. Asked
about his motivations for going underground, a member of the Italian Brigate Rosse
(BR) made this reply: â€˜â€˜There are many things I cannot explain by analyzing the political situation … as far as I am concerned it was up to emotional feelings, of passions
for the people I shared my life with.â€™â€™27
German militants of the Red Army Fraction (RAF) were also drawn into the
underground by devotion to friends. â€˜â€˜There is widespread agreement among researchers that â€˜most terrorists… ultimately became members of [German] terrorist organizations through personal connections with people or relatives associated with appropriate
political initiatives, communes, self-supporting organizations, or committeesâ€”the
number of couples and brothers and sisters was astonishingly high.â€™â€™â€™28,29
Devotion to comrades can lead a clique of friends to join a terrorist group
together. According to della Porta,30 â€˜â€˜block recruitmentâ€™â€™ occurred both for the
BR and the RAF. Sometimes a small political group would hold a meeting and if
the vote favored joining the underground, all would join together.
After an individual joins a radical group, love for friends and comrades in the
group is likely to increase further as common goals and common threats increase
group cohesion31 (see also Section 6 Group Radicalization under Isolation and
Threat). Interviews with 30 long-term members of Sinn Fein led White to conclude32
that group solidarity, along with hope of making a difference for the group and its
cause, were the two strongest forces holding militants together in the face of arrests
Mechanisms of Radicalization 421
and Loyalist attacks. Thus devotion to comrades is not only a force for joining a
radical group, it is equally or more a barrier to leaving the group.
White33 quotes one Republican as follows. â€˜â€˜Thereâ€™s times Iâ€™ve said to myself, â€˜Why?
Youâ€™re mad in the head, like.â€™ But…I just canâ€™t turn my back on it… thereâ€™s too many
of my friends in jail, thereâ€™s too many of my mates given their lives, and Iâ€™ve walked
behindâ€”Iâ€™ve walked behind too many funerals to turn my back on it now.â€™â€™
5. Group Radicalization in Like-Minded Groups
There is an experimental model of group radicalization that has been referred to
variously as â€˜â€˜risky shift,â€™â€™ â€˜â€˜group extremity shift,â€™â€™ or â€˜â€˜group polarization.â€™â€™ Groups
of strangers brought together to discuss issues of risk taking or political opinion
show consistently two kinds of change: increased agreement about the opinion at
issue, and a shift in the average opinion of group members. The shift is toward
increased extremity on whichever side of the opinion is favored by most individuals
before discussion.34 If most individuals favor risk before discussion, the shift is
toward increased risk taking. If most individuals oppose American foreign aid before
discussion, the shift is toward increased opposition to foreign aid.
The shift is not just a matter of go-along-to-get-along compliance; each group
member gives both pre-discussion and post-discussion opinion on a questionnaire
that only the researcher sees. Thus discussion among individuals with similar values
produces internalized shift toward more extreme opinions.
There are currently two explanations of group extremity shift.35 According to
relevant arguments theory, a culturally determined pool of arguments favors one side
of the issue more than the other side. An individual samples from this pool in assessing his or her individual opinion, then in discussion hears new arguments from
others, which, coming from the same pool, are mostly in the same direction as the
individual was leaning. The result is that individuals are rationally persuaded by
the imbalance of new arguments heard in discussion.
According to social comparison theory, opinion positions have social values
attached to them. All individuals feel pressure toward agreement, that is, pressure
to move their opinions toward the mean opinion of the group. But the pressure is
not uniform. Individuals more extreme than average in the group-favored directionâ€”the direction favored by most individuals before discussionâ€”are more
admired.36 They are seen as more devoted to the group, more ableâ€”in sum, as better
people. This extra status translates into more influence and less change during group
discussion, whereas individuals less extreme than average in the group-favored direction have less influence and change more. No one wants to be below-average in support of the group-favored opinion, and the result is that the average opinion
becomes more extreme in the group-favored direction.
A vivid description of the power of social comparison in radicalizing the
Weather Underground, a U.S. anti-war group of the 1970s, is provided by Collier
& Horowitz.37 Within-group competition for the status of being â€˜â€˜most radicalâ€™â€™
moved the group to terrorism. The hallmark of this kind of radicalization is the
extent to which the personal becomes politicized: every act is judged by political
standards, including who sleeps with whom.
Both relevant arguments and social comparison explanations are necessary to
explain the pattern of experimental results.38 In support of relevant arguments,
research shows that manipulating arguments without knowledge of positions can
422 C. McCauley and S. Moskalenko
change the size and direction of the group shift. In support of social comparison,
research shows that knowledge of othersâ€™ opinions without knowledge of othersâ€™
arguments can yet produce group shift. The two explanations are complementary
rather than redundant. Both conduce to increased similarity and increased extremity
in a group of like-minded individuals.
6. Group Radicalization Under Isolation and Threat
The model for this kind of radicalization is the powerful cohesion that develops in
small combat groups. Soldiers in combat are largely cut off from all but their buddies
in the same platoon or squad. This isolation is characteristic also of terrorist cells,
whose members can trust only one another. As both soldiers and terrorists depend
on one another for their lives in fighting the enemy, extreme interdependence
produces extreme group cohesion. This is a cohesion that can make group members
closer than brothers. Recipients of the U.S. Medal of Honor include many who
sacrificed themselves to save others; some literally threw themselves on top of a grenade to save their buddies.39
Very high levels of cohesion in a group mean very strong pressures for agreement of group members. Group dynamics theory distinguishes between two sources
of attraction to a group: the value of material group goals and the value of the social
reality created by the group. Material goals include the obvious rewards of group
membership, such as progress toward common goals, congeniality, status, and
security. Less obvious is the social reality value of the group: there are many questions of value for which the only source of certainty is group consensus. What is
good and what is evil? What is worth working for, worth dying for? What does it
mean that I am going to die? Certainty about these crucial human questions can only
come from agreement with others.
Thus high cohesion brings high pressures for both behavioral compliance and
for internalized value consensus. It is obvious to group members that they have to
pull together in order to reach group goals, and the result in many cases is complianceâ€”go-along-to-get-along agreement that does not bring interior certainty. But
the social reality value of the group depends on internalizing group standards of
value, including moral standards.
Groups differ in their power to set moral standards. The social reality value of a
group is weak to the extent that members belong to other groups with competing
standards of value. Conversely, the social reality value of a group is strong when
members are cut off from other groups. This principle is the foundation of many
powerful forms of group-focused persuasion, including cult recruiting and thought
reform or brainwashing. When cohesion is very high, as when an individualâ€™s social
world has contracted to just the few friends in his combat group or his terrorist cell,
the social reality value of the group is maximized. The groupâ€™s consensus about value
and morality acquires enormous power, including the power to justify and even
require violence against those who threaten the group.
This joining of cause and comrades in a high cohesion group is the goal of military training in every state, and is equally the foundation of terrorist violence against
states. One practical implication is that something important happens when a radical
group goes underground as a terrorist group. The combination of isolation and outside threat makes group dynamics immediately more powerful in the underground
Mechanisms of Radicalization 423
cell than in the radical group that preceded it. The power of relevant arguments and
social comparison is multiplied in an underground group.
7. Group Radicalization in Competition for the Same Base of Support
Groups in competition for the same base of sympathizers can, like individuals, gain
status by more radical action in support of the cause.40 Analysts have suggested that
the 1979 assassination of Lord Mountbatten by the Irish Republican Army in 1979
was an effort to compete with escalated attacks by the Irish National Liberation
Army, and that the 1985 hijacking of both a TWA plane and the luxury liner Achille
Lauro were attempts by Palestinian terrorists to gain advantage over rival groups.41
Today it is common to see more than one group claiming credit for a particular
terrorist attack, even for a particular suicide terrorist attack.42
Radicalization by competition is particularly clear in the case of the Armenian
Secret Army for the Liberation of Armenia. ASALA first gained diaspora support
by attacking Turks at a time when main-line Armenian organizations were only talking about retribution for the Turkish genocide of Armenians. One of the older
organizations (Tashnaks) responded to the new competition by establishing its
own anti-Turkish terrorist group, the Justice Commandos of the Armenian
Genocide.43 Similarly, the Palestinian Front for the Liberation of Palestine was
forced to take up suicide terrorism despite its materialist Marxist logic when PFLP
began to seem irrelevant in the second intifada.44
It is possible for a group to become too radical and lose its base of support. The
line between higher status from more radicalization and lower status from too much
radicalization is fine and variable over time. That it is possible to go over the line is
indicated by examples when the IRA expanded its targets beyond what its republican
sympathizers would accept; on such occasions the IRA would apologize and narrow
its target range, at least for a period of time.45
Similarly, Palestinian suicide terrorism attacks against Israel slowed dramatically in the period after the Oslo Accords. Hope of a peace agreement was associated with decreased support for terrorism, as reported in polling of
Palestinians. When the promise of the Oslo Accords was lost and the second intifada began, polls showed support for terrorism rising to new highs even as the
number of terrorist attacks rose to new highs. It appears that in many cases terrorism increases with popular support for terrorism, but can decline if popular support for terrorism declines. All too often, however, more radical action brings
more status and more support to a group competing with other groups to represent the same cause.
An often-overlooked aspect of competition for a base of support is violence
against competitors. About one quarter of the killing in Northern Ireland was
Catholics killing Catholics and Protestants killing Protestants.46 Both sides killed
suspected informers or individuals resisting the discipline militants sought to impose.
The IRA in particular attacked and killed those ignoring IRA strictures against selling drugs.
An extreme example of ingroup violence is the Tamil Tigers, who, in their rise to
power, killed more Tamils than Sinhalese.47 The LTTE early wiped out competing
Tamil militant groups, and continued in 2006 killing individual Tamil critics and
Tamil political opponents. An example that permeated the Western press was the
424 C. McCauley and S. Moskalenko
July 29, 1999, suicide-bomb killing of Dr. Neelan Tiruchelvam. As a leader of
the Tamil United Liberation Front and a Member of the Sri Lankan Parliament,
Dr. Tiruchelvam was a leading critic of human rights abuses by the LTTE.
From a group dynamics point of view, threat from ingroup competitors is like
threat from an outgroup enemy in producing high cohesion, with resulting high
pressures for conformity and strong sanctions against deviates. From an individual
point of view, when my friends and I are risking all for the cause, and especially
after some of our friends have died for this cause, no one can be allowed to betray
our sacrifice. The competition for ingroup support is a competition for survival, in
which violence against an outgroup enemy is often joined with violence against
8. Group Radicalization in Competition with State Powerâ€”Condensation
This form of radicalization has been a focus of research by social movement theorists.48 A group with weak and diffuse popular support attains sufficient organization
to make a public display: a rally, a protest march, a sit-in, or some other form of civil
disobedience. The power of the state is exerted to quash the group, often in the form
of police response that may include indiscriminate violence or some abrogation of
civil or human rights. The result is an increase in sympathy for the victims of state
repression and some mobilization of the groupâ€™s sympathizers toward action. (This
dynamic is considered later in relation to mass radicalization.) For social movement
activists, however, there is another dynamic at work, a dynamic of condensation.
Of all those who take the first radical actionâ€”joining an illegal rally or march or
sit-inâ€”most are likely to respond to repression by giving up action. They see the
costs as too high to continue. Others will not be deterred and will increase their commitment and escalate their action against the state. The determinants of this choice
are not well studied, but probably those who bring a moral frame and personal grievance are less easily deterred. In any case, the result of the interaction between state
and non-state group is often a mutual escalation of violence between group and
police, with further peeling off of individuals whose radicalization is not sufficient
to face increasing state pressure. The conclusion of this cycle of escalation and
self-selection is likely to be that a tiny fraction of the original protest group has condensed into a highly radicalized group that goes underground as a terrorist cell.
This cycle of reaction and counter-reaction has been described by della Porta in
her research on the origins of the Brigate Rossa in Italy and the Red Army Faction
in Germany.49 The Red Brigades condensed out of 1960s leftist student protest
movements in Italy; the RAF condensed out of similar leftist student protest groups
in Germany. Sprinzak50 has described a similar trajectory by which a tiny fraction of
the Students for a Democratic Society, who began with protest against the war in
Vietnam, condensed into the Weather Underground.
Radicalization by condensation depends upon the strength of the affective ties
between individuals, in particular ties to individuals who suffer from the state reaction to radical challenge. Comrades imprisoned cannot be abandoned; comrades
killed in police shootouts or in prison are martyrs whose deaths demand a response.
The reaction in many cases is increased commitment to violence to pay back state
Della Porta51 offers a number of examples of individuals for whom the death or
imprisonment of a comrade was the instigation for joining a terrorist underground.
Mechanisms of Radicalization 425
Anger and revenge are no doubt important in this kind of reaction, but a kind of
â€˜â€˜survival guiltâ€™â€™ may also contribute. Those alive and free feel guilty that a better
man or woman is dead or in prison. Research toward understanding survival guilt
has only recently begun,52 and may play a part in understanding the political power
This power is evident in an example offered by della Porta:53 â€˜â€˜For example,
Volker Speitel, one of the militants who worked in political groups that supported
the RAF militants in prison, described how the death of Meins (by hunger strike)
pushed him to the final step of joining the underground: â€˜Then the day came when
Holger Meins died … For us this death was a key experience … The death of Holger
Meins and the decision to take arms were one and the same thing. Reflection was not
9. Group Radicalization in Within-Group Competitionâ€”Fissioning
The within-group competition for status represented in social comparison theory can
produce intense conflict. The downside of conflating the personal and the political
is that differences of political opinion can lead to personal animositiesâ€”and vice
versa.54 Some observers have suggested that only common action against the state
or another group can save a terrorist group from tearing itself apart.55
Systematic data are lacking, but examples suggest that intra-group conflict leads
often to splitting or fissioning of a terrorist group into multiple groups. The IRA provides an obvious example, with many competing factionsâ€”Official IRA, Provisional
IRA, Real IRA, Continuity IRA, INLAâ€”who sometimes targeted one another. Similarly a split within ASALA was the occasion of killing between former comrades.56
Intra-group competition can go beyond killing. A threat from members of our
own group is likely to produce a feeling of contamination that requires not just death
but torture and obliteration. Such was the fate, evidently, of 14 members of the Japanese United Red Army who in 1972 were found dead and dismembered in a group
From a group dynamics perspective, the tendency toward fissioning in radical
groups should not be surprising. As already noted, cohesion leads to pressures for
agreement within the group. When, as in an already radical group, perception of
external threat produces very high cohesion, the pressure for agreement is very
strong. An individual will seldom be able to resist the pressure of a unanimous
majority, but a minority of two or more individuals may be able to resist.58 When
the pressure for agreement is very strong, the minority is likely to be expelled from
the groupâ€”or obliterated.
10. Mass Radicalization in Conflict with an Outgroupâ€”Jujitsu Politics
This form of radicalization can be understood as a generalization of the group
dynamics theory already described. In small face-to-face groups, outgroup threat
leads reliably to increased group cohesion, increased respect for ingroup leaders,
increased sanctions for ingroup deviates, and idealization of ingroup norms.59 In larger groups, reference to cohesion is often replaced with reference to ingroup identification, patriotism, or nationalism, but the pattern in response to outgroup threat is
similar to that seen in small groups. Consider the results of the 9=11 attacks on U.S.
426 C. McCauley and S. Moskalenko
politics:60 increased patriotism visible in rallies, flags, banners, and bumper stickers;
increased support for the president and for every agent and agency of government;
increased sanctions for Americans challenging the consensus (Bill Maher sacked for
suggesting the 9=11 attackers were not cowards); and reification of American values
(â€˜â€˜they hate us for our valuesâ€™â€™).
Mass radicalization by external attack is so reliable that it can be used as a strategy. Some terrorists have explicitly sought to elicit a state response that will carry far
beyond the terrorists to strike terrorist sympathizers who have not yet been mobilized to action.61 The predictable result is to mobilize terrorist sympathizers far
beyond what the terrorists can accomplish alone. We call this strategy jujitsu politics:
using the enemyâ€™s strength against him.62
Dr. Ayman Al Zawahiri enunciated this strategy in his political memoir Knights
Under the Banner of the Prophet.
63 If the shrapnel of war reach American homes, he
opined, Americans will either give up their aims in Muslim countries or will come out
from behind their Muslim stooges to seek revenge. If Americans move into Muslim
countries, he predicted, the result will be jihad. Although the U.S. war against the
Taliban was faster and cleaner of collateral damage to civilians than Al Qaeda
had expected, the U.S. move into Iraq has indeed been associated with increasing
support for radical Islam in Muslim countries.
11. Mass Radicalization in Conflict with an Outgroupâ€”Hate
It is often observed that groups in conflict, especially if the conflict involves prolonged violence, become more extreme in their negative perceptions of one another.
This tendency can become so extreme that the enemy is no longer seen as human.64
Dehumanization is signaled by referring to targets as â€˜â€˜pigs,â€™â€™ â€˜â€˜dogs,â€™â€™ or, more
abstractly, â€˜â€˜wheelsâ€™â€™ in the enemy machine. Della Porta65 quotes an Italian militant
as follows: â€˜â€˜ … enemies are in a category, they are functions, they are symbols. They
are not human beings.â€™â€™
Dehumanization can occur in interstate conflict as well. In WWII, for instance,
about half of American soldiers favored wiping out the whole Japanese nation once
the war was won. This radical opinion did not depend on membership in a high
cohesion combat group, nor did it depend on experience of losses in combat against
the Japanese. Indeed soldiers in training in the U.S., who had never been in combat,
were even more likely than combat soldiers to favor exterminating the Japanese after
the war was won.66
Similarly it has been observed that residents of English cities never bombed by
the Germans during WWII were more bloody-minded and vengeful than residents of
London and other cities of southern England that felt the full fury of the Blitz.67
Apparently group identification in the context of group conflict can lead to radically
punitive attitudes even in the absence of personal victimization by the enemyâ€”
perhaps especially in the absence of personal victimization.
A high level of categorical hostility toward another group is often described as
hatred. Some theorists believe that hate is an emotion, perhaps a combination of
anger, fear, and contempt.68 A more recent view is that hate is an extreme form of
negative identification that includes the idea that members of the enemy group share
a bad essence.69 In this view hate is not an emotion but the occasion of experiencing
many emotions, depending on what happens to the hated target. As above, positive
Mechanisms of Radicalization 427
emotions are occasioned when bad things happen to the hated group, and negative
emotions are occasioned when good things happen to the hated group.
The idea that the enemy shares a bad essence can make sense of the impulse to
attack all of them, without regard for age, gender, or civilian status. A groupâ€™s
essence is the hidden something shared by group members that gives them their
tendency toward shared group characteristics.70 A groupâ€™s essence is understood
to be stable over historical time and immutable for the individual group member.
If the essence is bad, there is nothing to be doneâ€”negotiation and education can
no more make a difference than negotiation or education can make a difference in
the essence of a tiger. If tigers threaten us and hurt us, all tigers are targetsâ€”old,
young, in uniform or out of uniform.
12. Mass Radicalization in Conflict with an Outgroupâ€”Martyrdom
The root meaning of martyr is witness, and there is something particularly powerful
about a form of witnessing that takes the life of the witness. One way to think about
the issue is to consider the psychology of persuasion, in which a credible source combines expertise and trustworthiness.71 A martyr is trustworthy insofar as it is difficult
to see how an individual giving up life for a cause could be lying for some personal
interest or advantage. This leaves the question of expertise, and the social construction of a martyrdom has to rule out the possibility that the martyr is â€˜â€˜crazyâ€™â€™ or
otherwise unable to choose death freely.72 It follows that higher status martyrs make
better witnesses: better educated, more successful individuals, with more life choices
available, are seen as knowing better what they are doing when they give their lives
for a cause.
Radical groups try to keep salient the memory of their martyrs. The Liberation
Tigers of Tamil Eelam yearly celebrate three days of Martyrsâ€™ Day activities, including honoring the parents of dead heroes. Palestinians killed by Israel are remembered
with portraits, graffiti, shrines, and rallies such as are often held in Martyrâ€™s Square
in Gaza. Palestinian web sites offer videos made by suicide terrorists before their
As noted earlier in relation to Holger Meinsâ€™s death by hunger strike, there is
reason to believe that the political impact of martyrdom can be significant. Mahatma
Gandhiâ€™s hunger strike against British rule in India is probably the most famous
example, although this was not a fast to the death. Perhaps the strongest example
is recounted in Ten Men Dead,
73 the history of IRA and INLA prisoners who died
on a hunger strike to protest British efforts to treat political prisoners as common
criminals. The men died over a period of 73 days. Several hunger strikers were
elected to the Irish or British parliaments, and many observers believe that the hunger strikes resuscitated a moribund Provisional IRA.
The social construction of martyrdom is under-theorized (but see note 74), and
empirically under-developed, but the impact of martyrdom on mass audiences
deserves close attention.
Radicalization as Opposition Politics
We began with a conceptualization of political radicalization as change in beliefs,
feelings, and action toward support and sacrifice for intergroup conflict. We noted
that these aspects of radicalization are only moderately correlated, and suggested
428 C. McCauley and S. Moskalenko
the value of differentiating these aspects both in conception and measurement. Then
we undertook a review of mechanisms of radicalization at individual, group, and
We do not suppose that the twelve mechanisms identified are the only important
ones. No doubt more will be uncovered. But we do expect that the more powerful the
radicalization, the more mechanisms will be implicated and the more artful their
mutual relation and reinforcement. Thus we suspect that the mechanisms considered
here in relation to political radicalization and terrorism may also be important in
understanding thought reform, cult recruiting, military training, and state preparations for interstate war.
Nor do we propose a single underlying theory uniting the twelve mechanisms
discussed here. Indeed it seems unlikely that any single theory can integrate all the
influences that bring individuals to radical political action, although a conceptual
framework in which to view these influences may be possible.75 It is unlikely that
any one of these mechanisms is sufficient to explain political radicalization, even
for a single individual. In every individual trajectory to terrorism of which we are
aware, multiple mechanisms can be identified. Thus the twelve mechanisms are
neither sufficient causes one by one nor instantiations of some larger theory. Rather
we suggest that there are multiple and diverse pathways leading individuals and
groups to radicalization and terrorism.
This view is consistent with previous research on psychology of terrorism and
social mobilization. For instance, Linden and Klandermans76 distinguish three pathways to extreme-right political activism: continuity, conversion, and compliance.
Some individuals show continuity in a lifetime of consistent political interest and
involvement. Of these, some are consistently involved in the same cause (revolutionaries) and some are consistent only in their involvement in one extreme group after
another (wanderers). Other individuals show a trajectory of sudden break with their
past in joining an extreme movement (converts), often following a dramatic personal
experience such as auto accident or rape. Finally there are individuals whose involvement in an extreme movement occurred through friends or relatives who persuaded
them to join (compliants), although they had not previously had much interest in
Similarly, Kimhi and Even77 argue that â€˜â€˜… not only is suicide terror a complex
multi-factorial phenomenon, but also seems to be a phenomenon of multiple trajectories.â€™â€™ Kimhi and Even identify four motive-trajectories among Palestinian suicide
terrorists. Religious motives for jihad and martyrdom, nationalist motives for liberation and independence of the Palestinian people, motives of retribution or revenge for
personal or group victimization by Israelis, and motives of escape from personal problems. These motives often overlap to considerable extent in particular individuals,
and the degree of overlap gives again an indication of the multiplicity and complexity
of pathways to terrorism.
This complexity is well summarized in the conclusion of Horganâ€™s chapter,
â€˜â€˜Becoming a Terrorist:â€™â€™78 â€˜â€˜The reality is that there are many factors (often so complex in their combination that it can be difficult to delineate them) that can come to
bear on an individualâ€™s intentional or unintentional socialization into involvement
Still, it is worth noting that there is a reactive quality to most of the mechanisms
identified. Of the twelve mechanisms, only two are more relatively autonomous. Individual radicalization in joining a radical groupâ€”the slippery slope is a mechanism of
Mechanisms of Radicalization 429
self-radicalization via self-justification, in which new beliefs and values are adopted
in order to make sense of past behaviors. These new reasons then support more
extreme behavior in the same direction. Group radicalization in like-minded groups
is also more an autonomous than a reactive mechanism: the events reacted to occur
within a group as arguments and individuals compete for acceptance.
The other ten mechanisms reviewed are more clearly reactive. They begin from
and depend on a dynamic of opposition in which the significant events are the
actions of others. Individuals react to personal victimization, to group grievance,
and to state action against friends and lovers. Non-state groups react to threat from
the state, threat from other groups competing for the same base of sympathizers, and
threat from internal dissension. Mass publics react to state action that injures indiscriminately, to martyrs, and, in long conflicts, to a perception of the enemy as less
The reactive character of these mechanisms is important because, as noted in the
introduction, efforts to understand radicalization usually focus on the non-state
actors who are radicalized. Terrorism research, in particular, tends to focus on
themâ€”the terroristsâ€”rather than on the situation they are inâ€”or, more precisely,
the situation they believe they are in. But these mechanisms do not operate only
in non-state groups challenging the state. The same mechanisms moving people
toward radicalization and terrorism will operate as well in those who react to radicals and terrorists.79 Even a cursory look at the experience of the U.S., since the
attacks of September 11, 2001, can suggest that those attacked have not escaped a
radicalization of their own.
The degree to which radicalization of non-state groups occurs in response to the
actions of others must be the starting point for understanding these groups. Political
radicalization of individuals, groups, and mass publics occurs in a trajectory of
action and reaction in which state action often plays a significant role. Radicalization emerges in a relationship of intergroup competition and conflict in which both
sides are radicalized. It is this relationship that must be understood if radicalization
is to be kept short of terrorism.
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Mechanisms of Radicalization 433
Mechanisms of Political Radicalization: Pathways