The ability of Islamic State to motivate people to join it, pledge allegiance and commit atrocities has been widely discussed. While some opinion writers and politicians suggest focusing on IS’s interpretation of Islam as a main factor, others tend to point to psychological and socio-economical factors which they argue contribute to the surprising extent of recruitment.Are people who join IS or are influenced by it psychopaths in the first place, or do they get sucked into evil through a process of radicalization? Clearly, it would be naïve to argue that the first option is the right one. Rather, people who willingly join IS are brainwashed by propaganda. The notion of the Khalifa or Muslim caliphate is apparently charming for the joiners, and another temptation to join lies in the clarity of vision IS offers: good vs. bad, saint vs. sinner.Social psychologist Arie Kruglanski points out that people with a high need for cognitive closure tend to be easier to recruit to terrorist groups. They are characterized by the desire to feel assured about the future and low tolerance for ambiguity, among others.While these are important aspects, it’s still unclear what goes on in the psyche of someone who decides to join IS, with the knowledge of the beheadings, crucifixions and other horrific acts IS commits. What happens at the birth of radicalization, when people cross the line toward the greatest taboo, taking human lives? The notorious videos of IS might provide a clue.Many start by showing images of attacks targeting Muslims, with the aim of presenting the IS act in the video as revenge. Psychiatrist Khwaja Khusro Tariq, relating to the term of psychoanalyst Vamik Volkan, “chosen trauma narrative,” points out that IS systematically aims to evoke the memory of persecution of Muslims, such that the victims in the group’s videos become dehumanized symbols of the enemy.The videos then present the atrocities themselves, and here too they are manipulative. Besides being of high cinematic quality, they censor the torment and terror of the person being killed. In his book The Science of Evil. On Empathy and the Origins of Cruelty psychiatrist Simon Baron-Cohen uses the term “empathy erosion” to explain how people are capable of causing extreme hurt to one another.He defines empathy as a double-minded focus of attention, with cognitive and emotional components, and lack of empathy as a state of focus on the self only. The cognitive component regards the recognition what another person is going through, and the emotional component reflects the ability to respond with an appropriate emotion. Empathy erosion can be transient and reversible or permanent (as in the case of some personality disorders, for instance) and it can arise through various factors such as corrosive emotions, beliefs (for example that one ethnic group is superior to another), tendency to conform. Baron-Cohen postulates that in the condition of empathy erosion, the empathy circuit in the brain functions abnormally. Regarding the IS videos, to which people can be widely exposed through the Internet, while people with proper empathy abilities would feel sickened and terrified by them, despite the censorship, because they would imagine the victim’s horror and pain, people with (even temporary) empathy erosion won’t experience these feelings, leaving only the cold recognition that someone is killed. Taking into account that empathy erosion can be driven by corrosive emotions (such as desire for revenge), it seems that the priming through images of violence toward Muslims/ Sunnis at the beginning of the videos serve the manipulation later on.In view of the above, it’s disturbing how easy it is to access the videos through the Internet. And the number of gore sites (sites, not secret forums!) makes one worry. One might argue that it’s impossible to prevent the upload of such videos anyway, because the jihadists will find new ways to post them. I suggest that work needs to be done in fighting IS propaganda videos online, by aiming to undermine their subtle dichotomy (the victim kneeling silently moments before his death, as if he acknowledges that it is justified). This might be achieved, for example, by educational videos explaining how IS videos turn people into mere objects. It might be a small, but important step of fighting radicalization. Before the line is crossed and evil becomes banal, as Hanna Arendt has pointed out.The author is a psychologist, living and working in Jerusalem.