(Originally published in the newspaper « Libération », December 4, 2015 in reference to the terrorist attacks of November 13, 2015 in Paris)

In the 70s, many social psychologists, especially Henri Tajfel highlighted the negative effects of a psychological mechanism seemingly innocuous: "social categorization". This mechanism, which can be seriously impaired in individuals diagnosed with schizophrenia, autism or Alzheimer’s disease (at an advanced stage), is the process of classifying people into groups based on presumably similar characteristics, whether it be nationality, religion, age, occupation, or some other traits. What could be more ordinary? Without this categorization process, it would indeed be difficult to understand and act on our social environment. The problem is that social categorization generates ipso facto two questionable effects. On the one hand an "assimilation effect" leading to exaggerate the similarities between members of the same category (thought to share the same personality traits, the same strengths and weaknesses, the same intentions, etc. ). On the other hand, a "contrast effect" leading to an exaggeration of the differences between members of distinct categories. The greater the simplification of social reality, the stronger the sense of understanding the world around us.
In addition to these assimilation and contrast effects, social categorization is also associated with a favoritism toward one's own group or category, which plays a fundamental role in our sense of a positive social identity, which is observed in almost all levels of society. In his famous minimal group paradigm, Tajfel and his colleagues showed that this ingroup bias can emerge from almost nothing: Just dividing individuals into two groups based on their aesthetic choices may be sufficient for this bias to occur. We therefore understand that Homo Sapiens, despite a tremendous capacity for empathy and compassion that sets them apart from other animal species, are nevertheless naturally ready to fight. All social stereotypes, propaganda, and all the barbarities across nations or groups heavily rely on these assimilations, contrasts, and ingroup favoritism effects. Combined with phenomena such as obedience to authority and pressure to compliance shown by Stanley Milgram and Solomon Asch, these effects explain, at least in part, why the worst events in human history recur over time. The efforts of memory and memorialization, as legitimate and important as they can be, will never be enough: Our most basic cognitive mechanisms are capable of the best and the worst when in contact with the soil of social tensions.
Indeed, under certain conditions (economic crisis, shortage of a particular resource, sense of deprivation, political or religious manipulation, etc.), social categorization and related biases are exacerbated. These conditions give rise to ideologies as well as individual and collective behaviors of cruelty and extreme violence, like the terrorist attacks in Paris. At the final stage, enemies, or those deemed as such, lose in the minds of the combatants, here terrorists, their individuality and often all or part of their status as human beings. The combatants do not kill men or women, they kill the "infidels" or "pigs" responsible for all evil (including that of listening to music) and suffering. This infrahumanisation or deshumanization of the enemy is often associated with an unprecedented glorification and proselytizing strategy from the combatants, whose power of seduction and attraction would obviously be zero in the absence of any fertile soil. Stuffed with propaganda, via the Internet in particular, candidates who go for jihad or wish to leave for Syria or Iraq are in this extremely simplistic view of a dichotomous world essentially made up of "infidels" and "unbelieving fighters". This simple categorization of reality opens up all the excesses.
Religion in the case of these "new ninjas of Islam" is an easy argument. Only few (if any) of them know the Qran or the history of Islam, but through their commitment most of them can find a positive social identity in their own eyes and even a form of glory which is missing in their ordinary life. From this perspective, the term "radicalization" is somewhat problematic. This term suggests a traditional religious practice that over time would have drifted into a sectarian ideology. However, the vast majority of terrorists arrested or killed in recent attacks do not have this profile. Not religious, often marginal and already known for delinquency (but not all), they were recruited by a group and admired its leader. On this basis, they have benefited in record time from an identity, which— if not socially valued—, gave them momentarily meaning to their existence. Faced with various frustrations accumulated throughout their ordinary life, this identity is especially functional: It generates fear and some promise of revenge.
However, how is it possible that some of these jihad candidates sacrifice their lives as suicide bombers? Again the work of social psychology, especially that of Jean-Paul Codol, are not without interest. They teach us that obedience and compliance with a particular standard or ideology often coexist with a concern for social differentiation. This differentiation in compliance takes the form of a "self-overconformity", which is to be more consistent than other members of the group to the ideology of the moment. This overconformity, which is not the prerogative of jihadists (remember the excessive zeal of some officials of the French police under the Vichy regime during World War II), marks somehow the most successful stage of the accession process. Precisely what a jihadi model reaches with its status of martyr.

pascal.huguet@univ-bpclermont.fr