Though investigators looking into the couple who opened fire on a holiday party last week at a San Bernardino social services agency, killing 14 and wounding 21, have not yet confirmed whether the pair may have been working on behalf of ISIS or any other foreign terror organization, a number of signs point to yes. One FBI official described the shooters, Syed Farook and Tashfeen Malik, as having been radicalized for quite some time. They had an arsenal of ammunition and pipe bombs at home and had taken part in target practice at local gun ranges. Wednesday, the FBI revealed that the couple had been discussing an attack for as long as two years.
If the massacre does prove to have been the work of killers inspired by Islamic militants, it would be the most deadly terrorist attack in the United States since 9/11. In light of this and other recent examples of domestic-born terrorists -- since 2001, there have been 314 arrests in the U.S. for "jihadist terrorism," defined as "violent extremism motivated by al-Qaeda and its affiliated groups" -- politicians and criminalists alike have been looking for ways to explain why and how an organization as brutal as ISIS might appeal to Americans and others who've grown up in modern, democratic, Western societies. What would cause someone to turn his or her back on family, friends, and Western comforts to commit horrific crimes and risk their own deaths? What would be the reason we're seeing a steady stream of young people traveling to the Middle East to join jihadists, including a growing number of young women and girls?
Theories vary. One is that some who have become radicalized may be motivated by their own experiences with discrimination or unjust treatment. Others may join out of fear, and the promise that aligning with ISIS will keep them safer now and, perhaps, in the afterlife. Still others may experience disenchantment with Western ideals or have been disappointed by Western promises of freedom, employment, or financial stability. Through social media, ISIS has also engaged many younger Westerners who feel isolated and angry, and are seeking an outlet in which to rebel.
But there's also another explanation that's been talked about less, and that's mental illness. The idea that radicalization may be a mental health disorder, or at the very least linked to one, is just beginning to be examined. A study funded by the U.S. Justice Department found that "lone wolf terrorists," individuals motivated by the ideology of a certain group who act alone, are prone to mental illness, often acting from some combination of personal grievance and triggering event.
Other studies have suggested that violent radicalization may be related to abnormal personality development during the early years. In one recent study, researchers in the UK looking at ways to understand, and prevent, violent radicalization found a correlation between extremist sympathies and "being young, in full-time education, relative social isolation, and having a tendency towards depressive symptoms." In contrast, they found, "frequency of religious worship and attending a place of worship were not correlated with extremist leanings." Translation: When it comes to identifying with the mission of terrorist groups, religion may matter less than mental wellness.
It's not that radical an idea. Think about it: We know that depression is associated with negative thoughts, a sense of hopelessness, and impulsive and irritable behaviors. These characteristics can leave people, especially younger people, vulnerable to all sorts of influences, but particularly ones so strong-willed as extremism. For individuals who may be struggling with identity or feelings of alienation and instability -- which is the case for many who suffer from mental illness -- the rigid doctrines of radical Islam can provide some appealing structure. If you feel shut out from a society, wouldn't it be possible you may feel drawn to a movement that promises to overturn that society?
Of course, this isn't to say that all people who are drawn to terrorist groups suffer from mental illness, or that all those who suffer from mental illness are at risk for becoming radicalized -- just as conversion to Islam cannot be seen as a cause of violence or acceptance of radical ideology.
What these findings do suggest, however, is that trouble often emerges when radical ideology combines with other personal problems, including mental illness. Which makes radicalization not only a political or criminal matter, but quite possibly a public health one as well -- certainly another reason to reframe the discussion surrounding the causes of terrorist acts, and to argue for an increase in the resources available for preventing, identifying, and treating mental illness.
There's just no reason not to.