When Islamic State (Isis) launched its attack on Mosul in 2014, they were outnumbered by opposition forces by almost 40 to one – yet Isis took the city. Now a group of scientists working on the frontline in Iraq have analysed what motivates such fighters in research they say could help combat extremists.



While predicting the will to fight has been described by the former US director of national intelligence James Clapper as “imponderable”, researchers say they have begun to unpick what leads members of groups including Isis to be prepared to die, let their family suffer or even commit torture, finding that the motivation lies in a very different area to traditional ideas of comradeship.

“We found that there were three factors behind whether people were willing to make these costly sacrifices,” said Scott Atran, co-author of the research from the University of Oxford and the research institution Artis International.

Those factors, he said, are the strength of commitment to a group and to sacred values, the willingness to choose those values over family or other kin, and the perceived strength of fighters’ convictions – so-called “spiritual strength” – over that of their foes.

The findings support the idea, put forward by previous research, that the will to fight lies not in rational action but in the idea of the “devoted actor” – individuals who consider themselves strongly connected to a group, fighting for values considered to be non-negotiable, or “sacred”.

Writing in the journal Nature Human Behaviour, Atran and an international team of colleagues describe how they came to their insights by travelling to the frontline in Iraq.

As well as speaking to captured Isis fighters, the team carried out in-depth interviews with Arab Sunni combatants, as well as Kurdish fighters from the PKK, Peshmerga and members of the Iraqi army. The frontline approach, the authors note, was crucial to capturing the sacrifices individuals actually make for their values, rather than merely what they claim they might do.

The results revealed that all followed the model of “devoted actors”, but that the level of commitment to making costly sacrifices, such as dying, undertaking suicide attacks or committing torture varied between groups. With the sample size of fighters small, the team also quizzed more than 6,000 Spanish civilians through online surveys.

The results revealed that the majority of civilians placed their family above a value they considered sacred. However, in a finding that echoed evidence from the frontline, the team discovered that those who placed their sacred value above their group said they were more willing to make dramatic, costly sacrifices such as dying, going to prison or letting their children suffer.

Surveys of the Spanish population also revealed that they made links between spiritual – but not physical – strength and the willingness to make sacrifices.

But the team stress that decisions made by devoted actors on the frontline were not made without emotional turmoil.



“One particular Peshmerga fighter had to make a decision when the Islamic State guys decided to enter his village – he wasn’t in a position to take his family with him and escape and get in front of the Isis fighters, and so what he did was he left his family behind,” said Richard Davis, co-author of the research from the University of Oxford and Artis International.

While being interviewed, the fighter received a phone call from his wife behind Isis lines, knowing the penalty if caught would be death. “You could see the man getting emotional, and as he gets off the phone, he begins to lament the decision that he had to go through to leave his family behind, but he indicated that fighting for Kurdistan was more important, and that he hoped that God would save his family,” said Davis. “When you hear things like that and you see a broken man – then you recognise how difficult this was for people.”

The team note that understanding the willingness to fight and die among devoted actors could prove valuable in fostering forces against Isis, including in exploring ways to elicit deeper commitment to, and willingness to sacrifice for, values such as democracy and liberty.

“Instead of just taking volunteers into an army, we might be able to screen who we put into the army based upon the types of values they commit to, and this would create an entirely different fighting force than the one that melted in Mosul in 2014, ” said Davis, adding that the study could also inform efforts attempting to prevent fighters from joining Isis.

Stephen Reicher, professor of social psychology at the University of St Andrews welcomed the research, adding that it contributed to the understanding of fighters as “engaged followers”. “The fundamental finding is that those prepared to kill – and die – for a cause are to be understood not in terms of a distinctive personality but in terms of their immersion in a collective cause and their commitment to the ideology of that cause,” he said.

