09/12/2011 07:29 pm ET Updated Nov 12, 2011

Ten Years After 9/11: The Suicide Angle

The easiest reaction is to just pick a side. Either the September 11, 2001 hijackers were psychologically normal, or they were insane. Ten years after that fateful day, this false dichotomy continues to distort explanations of why the United States was attacked.

Perhaps we shouldn't be surprised. We have seen almost this exact same mistake made before. For nearly a decade after the deadly Columbine school shootings, commentators were still applying the either/or fallacy to Eric Harris. They assumed that the teen gunman, who along with Dylan Klebold killed 13 people and wounded 24 more in April 1999, was either normal or insane. In his case, most chose the former. Fellow students suggested that he was a social outsider, but certainly not a crazy person. Common explanations centered on the belief that bullying had simply pushed this lonely kid over the edge, and that if not for this abusive treatment, he could have lived an ordinary life.

The truth is that Eric was neither normal nor insane -- he was a psychopath. This third category defies overly simplistic classifications. Eric could hold a seemingly rational and friendly conversation with parents, teachers, and counselors. He could plan his future actions with the diligence and concentration of a highly successful student. But he could also lie without hesitation and kill without conscience. That is what made Eric different, and in the opinion of a team of psychiatrists and psychologists assembled by the FBI, it was only a matter of time before he exploded.

For the past ten years, the 9/11 hijackers have similarly been labeled "normal," simply because they were not insane. Jerrold Post, a former CIA officer and director of the political psychology program at George Washington University, stated that "We'd like to believe these are crazed fanatics, and some sort of madmen in the grip of a psychosis. Not true. This is the norm." In turn, Robert Pape, a political scientist at the University of Chicago, claimed that 9/11 ringleader and pilot Mohamed Atta's "psychological history, motivations, and behavior do not appear terribly different from those of... many soldiers from many cultures who saw their societies in desperate struggles for survival." Numerous other scholars and government authorities have similarly asserted that despite their radical ideology, suicide terrorists are "psychologically normal" and "psychologically stable."

However, new research has shown that many suicide terrorists were in fact suicidal, for many of the same reasons other people become suicidal, such as depression, hopelessness, guilt, shame, and rage. Much like Eric Harris's psychopathy, this represents a third category between normal and insane. Suicidal people are certainly not the norm, but most do not suffer from crazy delusions or hallucinations either. The vast majority can make rational and premeditated plans, and many strategically orchestrate their deaths for symbolic effect on an audience.

Some of the best evidence of the suicidal motives of suicide terrorists comes from Ariel Merari, a professor of psychology at Tel Aviv University in Israel, whose research team recently assessed 15 preemptively-arrested suicide bombers. The results were fascinating: 53 percent displayed depressive tendencies, 40 percent displayed suicidal tendencies, and 13 percent had previously attempted suicide, unrelated to terrorism. When extrapolated, these findings suggest that many of the Al Qaeda terrorists who struck on September 11, 2001 would have also been depressed or suicidal.

The details from the individual 9/11 hijackers' lives support this view. For instance, terrorist pilots Mohamed Atta, Marwan al Shehhi, Hani Hanjour, and Ziad Jarrah all struggled with a range of personal problems that could help explain their suicidal intent. Atta dealt with social isolation throughout his life, showed numerous signs of depression and life-weariness, and had lamented wasting most of his life. Al Shehhi had been devastated by the death of his father, had major difficulties at school, and had grown estranged from the rest of his family. Hanjour was extremely timid, insecure, and shy, had very few friends, and was a poor student with limited career prospects. And Jarrah had complained about being dissatisfied with his life, nearly flunked out of high school, and had dropped out of college.

Details on the other 9/11 hijackers' lives are harder to come by, but some appear to have been suicidal as well. In fact, one of the original suicide terrorists selected for "the planes operation" was Tawfiq bin Attash. Before 9/11, in one terrible battle in Afghanistan, he had been severely injured, lost his lower right leg, and watched his brother be killed before his eyes. After this traumatic series of events, bin Attash volunteered to carry out a suicide mission. As luck would have it, he could not gain entry to the U.S. and could not participate in 9/11, but these types of clues help explain why he -- and other suicide terrorists like him -- want to die.

Of course, this does not negate the role that radical ideology had in their decision to attack the United States on September 11, 2001. People can simultaneously want to die and want their deaths to have various long term effects. Perpetrators of murder-suicide often claim to have broader, ideological motives, whether it's Neo-Nazism, eugenics, masculine supremacy, or Islamic fundamentalism. At Columbine, Eric Harris hoped his actions would send an intimidating message to onlookers, and the 9/11 terrorists clearly had an agenda as well. Their political and religious beliefs may have affected the method of their suicide and their choice of target, even if their desire to die was the underlying cause of their behavior.

Ultimately, what makes these attackers abnormal is their homicidal and suicidal intent -- not their ideology. There are millions of relatively normal people around the world who claim that suicide attacks are actually justified. But despite their views, the vast majority are unwilling to kill others and kill themselves -- no matter what they believe in. By contrast, most suicide terrorists are not psychologically normal, but they are also not insane. At the root, they're suicidal. More than anything, that is why they kill themselves and take innocent victims with them.

No matter what they claim.