Do you know anyone capable of committing a war crime? Psychologists suggest a surprising answer.

As the situation in Syria deteriorates, are the psychological factors which predict war crimes, such as massacres, rapidly escalating there? This appears to be the implication of a psychological study into the most terrible examples of mass violence entitled 'Extreme mass homicide: From military massacre to genocide', published in the prestigious academic journal Aggression and Violent Behaviour.

Donald Dutton, Ehor Boyanowsky and Michael Harris Bond from the University of British Columbia and Simon Fraser University, Canada, and Chinese University of Hong Kong, published findings, which if extrapolated to Syria today, would suggest that escalating atrocities of historic proportions are imminent.

This study argues war crimes have been occurring with increasing frequency in the modern epoch across the world, so it's likely the conditions for such atrocities to occur are much closer to hand than we are comfortable acknowledging.

They list examples such as in 1914, about one million Armenians were massacred by the Turks. 20 million Eastern Europeans, six million Jews, five million Slavs, Gypsies, and others were destroyed by Nazis between 1933 and 1945. Stalin terminated up to 30 million dissenters in the Soviet Union while Mao Zhe Dung supervised the murder of up to 20 million bourgeoisie in China. The Pol Pot led Khmer Rouge targeted 2.5 million educated people in Cambodia for slaughter between 1974 and 1978. In Rwanda in 1994, over just three months, Hutus slayed around 800,000 Tutsi.

But it's not just numbers killed which creates a psychological and moral conundrum, but the manner of the killing in many cases which appears utterly baffling, given these atrocities are being committed by what would be considered large numbers of otherwise psychologically normal individuals. Yet they go on to perform gross 'overkill'.

The authors cite as an example the infamous 'Rape of Nanking' which occurred during the Sino-Japanese war in 1937. Until Rwanda, this was the largest short-term mass extermination in history, with 250,000 estimated killed. Chinese men and soldiers were bayoneted routinely, after being sodomised or forced to perform sexual acts with members of their own family, women were gang raped, sodomised, vaginas crammed with foreign objects (also a feature of the Rwandan massacre). Men and women were disembowelled while babies were thrown into the air and impaled on bayonets, then chopped up. This also happened during the civil war in El Salvador, notably the massacre at El Mozote in 1991.

In an intriguing echo of what may be happening right now in Syria, given how difficult it is for the press to report from inside, the U.S. government knew what was transpiring in Nanking but kept it from the public. Pearl Harbor was yet to happen in 1941 and the North American government feared public outrage, propelling the authorities into a war they didn't want at the time.

While claims of a civilian massacre in the Syrian town of Tremseh remain disputed, with UN observers now reporting that most of the dead were combatants, and not civilians, a number of the victims seem to have been shot at close range. Such 'execution-style' killings, apparently carried out by pro-Assad militia, are disturbing clues that all the psychological antecedents to war crimes are falling into place in Syria.

Local activists had initially claimed a slaughter of 220 civilians, but whatever actually happened, Tremseh shares the same religious outlook as two other Sunni villages whose inhabitants were allegedly recently massacred by the surrounding Alawite communities. In both previous cases, numerous women and children were found among the corpses.

The focus on who actually died is missing the psychological warning signs of the kind of mentality associated with war crimes, which is more about the manner of the killing.

Dutton, Boyanowsky and Bond argue in their paper that in a rationalization reminiscent of the Armenian genocide, one captain leading the El Mozote massacre in El Salvador, persuaded soldiers balking at the killing the children by declaring, "If we don't kill them now, they'll just grow up to be guerillas. We have to take care of the job now", he then threw a child into the air and impaled him on a bayonet, then most of the children were killed either by bayoneting or hanging.

The authors find certain factors seem to recur in massacres all across the world - the group who commit the war crime are frustrated and search for a scapegoat. In a book entitled Psychopathy and the Law Helinä Häkkänen-Nyholm and Jan-Olof Nyholm highlight how leaders suffering from 'malignant narcissism' then exploit what Dutton and colleagues refer to as our essential tribalism.

This is an echo from our evolutionary past, which leads to blaming anyone who can be reliably labelled as different from us, in the form of a target 'out-group' for the difficulties of the 'in-group'. The out-group becomes demonised and dehumanised, so legitimising extreme action against them, but also serving the goal of heightening in-group solidarity, which fulfils powerful psychological needs.

Psychologically we actually benefit from an enemy, as nothing promotes cohesiveness and solidarity amongst us, as an identifiable threat. It's no accident Dutton, Boyanowsky and Bond contend, that in Orwell's classic novel Nineteen-Eighty-Four a vague enemy was fought by the totalitarian regime in televised battles broadcast in all public spaces, on an incessant 24-hour anticipation of our modern 'rolling news'.

Dutton, Boyanowsky and Bond quote a famous psychoanalyst Erich Fromm (1900-1980) who referred to sadism as "the conversion of impotence into the experience of omnipotence". Fromm contended that sadism produces an emotional high, because absolute control over another, exemplified by inflicting pain or humiliation, provides a unique sense of power. Total dominion over another creates an illusion of transcending the limitations of human existence. It becomes particularly addictive for anyone whose reality is 'deprived of productivity and joy'.

So no one is probably immune to committing war crimes if the conditions are right. Therefore we need to be constantly vigilant to psychological processes such as 'groupthink', which Dutton, Boyanowsky and Bond highlight, with the emergence of self-appointed 'mind guards' whose job is to protect the group from adverse information.

Herman Goering, Commander in Chief of the Luftwaffe, at the Nuremberg Trials, declared that it didn't matter what kind of society you referred to - democratic, capatilist, socialist or whatever; 'people can always be bought to the bidding of the leaders. This is easy. All you have to do is tell them they are being attacked, and denounce the pacifists for lack of patriotism and exposing the country to danger. It works the same in every country.'

As it's working right now in Syria, why do we have to wait until the inevitable post-mortems to wring our hands over what can be prevented - especially when it can be predicted?

A free public debate, part of the long-running series 'The Maudsley Debates', is to be held at Guys Hospital Thursday 19 July 2012, where eminent psychiatrists, psychologists, experts and academics will debate Anders Breivik's mental state; what this case reveals about the link between fanaticism and psychological disturbance.

The title of the debate: 'Cases such as Anders Breivik demonstrate that fanaticism is a form of madness' is proposed by Dr Raj Persaud, a Consultant Psychiatrist. Co-proposing the motion is Dr Max Taylor, Professor of International Relations at The Centre for the Study of Terrorism and Political Violence at St Andrew's University.

Opposing the motion is Dr Simon Wesseley, Professor of Psychological Medicine at the Institute of Psychiatry, Kings College London. Co-opposing the motion if Maajid Nawaz, Chairman of the Quilliam Foundation.

The free public debate is to be held at Guys Hospital Thursday 19th July 2012 6pm in the New Hunts House Lecture theatre, Guy's Campus, London.

Weblinks: http://www.huffingtonpost.co.uk/dr-raj-persaud/anders-breivik-psychology-inside-the-mind-of-anders_b_1419343.html

For further information on the debate, http://www.iop.kcl.ac.uk/events/?id=1612