Why people become terrorists

How violent extremism emerges from complex social systems.

Part of a continuing series about complexity science by the Santa Fe Institute and The Christian Science Monitor, generously supported by Arizona State University.

In the aftermath of any terrorist act, our instinct is to try to make sense of the brutality by assigning a person’s or a group’s violent radicalization to one or two probable causes: religious extremism and economic disparity, for example.

If we could only find a simple cause, our thinking goes, we might find a simple solution – blocking the influx of potentially dangerous ideas and people, or sending more military power to excise terrorist strongholds. 

Such simplifications help us cope and make for powerful political messages, but it’s clear that no single factor can explain violent radicalization. Inevitably, such narrow-sighted reactions only make the problem evolve into a different, and potentially more dangerous, beast.

Welcome to complex social systems, where the interactions of many individuals immersed in particular socio-economic circumstances lead to the emergence of sometimes surprising social phenomena, from fashion trends to political movements, from conspiracy theories to financial crises, and from religious rituals to jihads.

Complexity science can help us understand the underlying social systems from which these problems emerge; we should let it guide us in developing a thoughtful, science-based policy for dealing with them.

What drives a terrorist?

Decades of research have, thus far, not revealed any common psychopathological symptoms among terrorists. They appear to want some of the same things most of us want: recognition from their peers and communities and better lives for the people they care about.

Being a devout member of a particular religion is not a good predictor of violence, either. Many deadly terrorist acts are unrelated to religious ideology. In recent years, Islamic values have been used to promote warmongering ideas across cultural and national borders by invoking the authority of widely revered holy figures and scriptures. But Islam is not terrorism and terrorism is not Islam.

Nor is the tactic of co-opting broadly accepted values or authorities to promote a certain idea unique to the current wave of “Islamic terrorism.” Politicians and interest groups routinely build on shared values such as freedom, family values, or religious doctrines to promote their agendas.

Economic circumstances are an important but not paramount contributor to violent radicalization in the West. Poverty and limited job opportunities do cripple one’s chances of achieving life goals, and discrimination is a real problem for many minorities. But very few poor or discriminated-against people become terrorists, and a significant number of terrorists have led stable middle-class lives.

Youth on the edge

So what can we say are the genuine markers of violent radicalization in the West today? As noted by anthropologist Scott Atran, political scientist Olivier Roy, and other prominent terrorism scholars, three consistent characteristics are common to recent perpetrators of terror, and these hold for past terrorist movements, as well:

• Terrorists tend to be young, rarely older than 30 and usually in their early 20s.
• Terrorists feel resentment toward mainstream society because of perceived or real injustices they have experienced, and they often feel frustrated that they are unable to obtain justice.
• Before they became violent, most terrorists spent time in close contact with like-minded peers or charismatic leaders.

In essence, we are dealing with disgruntled young people who do unexpected or dangerous things under the social influence of their peers and role models – a.k.a. the common adolescent. And yet, only a small fraction of disgruntled young people stumbles into behaviors that are significantly more dangerous than making severe fashion statements or partying excessively.

To understand how a seemingly “normal” person can become a terrorist, we need to understand not only how individuals are wired, but also how people are wired together.

Social animals

Social science suggests that all of us are defined by who we hang out with in at least three key ways:

1. The people around us influence how we perceive the global society. In other words, we use our own social milieu to make inferences about how people we don’t know live their lives. But this may backfire when we live in homogeneous social environments and rarely meet people living in different circumstances. English psychologist Rael Dawtry and his colleagues have shown, for example, that people who live in richer neighborhoods perceive income distribution in the general population as more fair than it really is. Consequently, they are less likely to support policies aimed at reducing the gap between rich and poor.

2. Our social circles have a strong influence on our own beliefs and behaviors. In the 1950s, conformity experiments by social psychologist Solomon Asch showed that some people will disregard objective facts if everyone else opposes them. More recently, social scientists Nicholas Christakis and James Fowler have found that people tend to mirror their social contacts when it comes to dietary habits, smoking and drinking, and even emotions. This similarity reflects the underlying processes of social influence and the tendency to befriend like-minded people.

3. We feel good when others agree with us and bad when they disagree. All of us have experienced unpleasant feelings arising when someone expresses opinions we profoundly disagree with. These feelings of anger and frustration were labeled cognitive dissonance by the psychologist Leon Festinger. They motivate us to try to influence disagreeing others, and if that fails, stop communicating with them altogether. 

What I’ve described so far are all useful aspects of human sociality that help us to learn from each other, form efficiently functioning groups, and stand as one against a common enemy when needed. In fact, many scientists agree that our ability to learn from and cooperate with others may be the cornerstone of the spectacular success of our species. But sometimes our advanced sociality helps spread beliefs that are harmful to a society.

How beliefs form and change

Complexity science — by its nature an amalgam of fields — permits us to pull together techniques and tools from cognitive and social psychology, network theory, anthropology, political science, economics, statistical physics, computation, and more for deeper quantitative insights into social systems than any single field can offer. This can help us study how our social-cognitive processes interact with and shape our social networks and our broader economic and political circumstances, and gives us hope of explaining when and why harmful beliefs spread.

Consider a social-cognitive process called social sampling. Our social environments – dominated by our social contacts and the media – constantly serve up a menu of beliefs and behaviors we might try. Most are harmless or beneficial, such as a new fashion fad or an improved technology. But some, such as excessive nationalism or denigrating entire ethnic or religious groups, can be very dangerous. Some people, depending on their social environments, and in particular on the diversity of their social contacts and media sources, will be exposed to such dangerous ideas more frequently than others.

A second important process, belief updating, determines whether we will accept a novel idea coming from our social environments. Its outcome depends on the strength of our own views, formed by a lifetime of experiencing our own particular societal circumstances. But it also depends on views of the social contacts we most respect, feel personally close to, or wish to impress. Hence, we are more likely to accept a dangerous idea if it aligns with our own experiences and is supported by the people we value.

A third, significant social-cognitive process is network updating. An easy way to avoid the unpleasant feelings of cognitive dissonance is to not discuss our beliefs with contacts who disagree, or to cease socializing with them altogether. As a result, our social circles become more homogeneous, and beliefs our former peers might have considered extreme are no longer challenged by anyone important to us.

None of these processes in isolation is dangerous per se. But taken together, in some societal circumstances, they can feed a spiral leading some individuals toward increasingly extreme and sometimes dangerous beliefs.

Systemic understanding

The social-cognitive processes I have described are shaped by millennia of human biological and cultural evolution. Suppressing them would not only be very difficult, it would also be counter-productive. In most parts of our lives, they are essential and desirable components of our exceptionally well developed sociality.

What we might change are the inputs to these processes: the content of individuals’ social samples, the personal experiences shaping their views, the diversity of their social circles, and the ease of making and breaking new social connections. In turn, these processes will feed back into and act upon our society. Understanding this cycle can help us design interventions that affect not only one of its parts, but have positive feedback effects throughout the system.

Consider, for example, interventions targeting the input to social sampling processes, such as paying attention to the information available to young people on social media, or crowding out dangerous ideas by suggesting alternative ways for young people to join exciting and meaningful causes and achieve peer respect. By altering the ingredients of the idea menu they are exposed to, we might, in turn, minimize the dangerous inputs to the processes of belief and network updating. 

Interventions targeting belief updating processes include exposing chauvinist and violent ideas disguised as legitimate spiritual or patriotic values. In many cases, these interventions would need to come from within the affected communities – and be championed by their internal role models.

Equally important for belief updating processes is improving the economic and political circumstances that limit young people’s opportunities to achieve life goals in non-violent ways. By eliminating some of the justifications for the acceptance of violent ideas and providing peaceful paths to self-realization, such interventions also shape the content of people’s social samples.

Interventions that target network updating, such as efforts to avoid alienating youth from mainstream society or to identify those in the process of withdrawing, will in turn affect inputs into their social sampling and belief updating processes. 

And so on. The social-cognitive-environment feedback cycle offers many potential points of intervention.

None of these ideas is new, of course. All have been tried or are being implemented in different countries and communities. Nor are they, in isolation, the final solutions to the problem of violent radicalization. 

Complexity science can help us take in the bigger, messier picture. We can build quantitative, empirically grounded computer models – simulations – of how these interacting processes interact with and influence people and the societies in which they are embedded. Within these models, we can try interventions and see if they succeed or fail. We can design ensembles of strategies with synergistic effects, then evaluate them and their effects on the system as a whole rather than as isolated tactics.

Ultimately, by thinking more deeply about the many ways we influence each other within our complex social circumstances, we might find ourselves better able to comprehend and cope with terrorism – and the other emergent social challenges that keep vexing us: the debate for and against immigration, the gun control conundrum, the ongoing redefinition of gender roles, or anger-fed political movements.

Mirta Galesic is the Cowan Chair in Human Social Dynamics at the Santa Fe Institute and an adjunct researcher at the Center for Adaptive Behavior and Cognition at the Max Planck Institute for Human Development in Berlin. She studies how simple cognitive mechanisms interact with properties of the external environment to produce complex social phenomena.