Why are so many terrorists brothers?
That’s what investigators and counterterrorism experts are trying to understand.
As the author of The Sibling Connection: How Siblings Shape Our Lives, it never dawned on me to explore this phenomenon. I wrote the first edition of the book in 1991, long before Sept. 11, 2001, the Boston massacre, the recent suicide bombings in Belgium carried out by Khalid and Ibrahim el-Bakroui.
In a March 23 article in The New York Times, journalists Jim Yardley, Rukmini Callimach, and Scott Shane talked to authors, counterterrorism experts, and psychologists to get some answers.
Here are five potential reasons why so many brothers are terrorists:
- Brothers often radicalize each other. One new study suggests that up to 30 percent of members of terrorist groups share family ties. Siblings who live in the same house can discuss ideology and plans without using cellphones which can be easily tapped.
- J. M. Berger, a terrorism analyst and co-author of “ISIS: The State of Terror,” said in the New York Times article that often siblings can talk to each other about things they can’t discuss with others.
- When we talk about siblings, there is often, but not always, a dynamic in which younger brothers tend to look up to and follow in their older brother’s footsteps. However, when terrorist brothers blow themselves up or are killed by law enforcement, the only way to verify this dynamic is to talk to family and friends, many of whom are unwilling to cooperate.
- If siblings are sent to different locations, chances are that the brothers will each carry out their mission, said Mia Bloom, co-author of “All in the Family: A Primer on Terrorist Siblings.” ” . . . they don’t want to disappoint their siblings and cannot face the idea of going on without them.”
- Psychologists who study terrorism and interviewed by the New York Times, say that the two-person cell may be a recent adaptation to increased security measures — whether they are brothers, as in Brussels, Paris and Boston, or husband and wife, as in the San Bernardino, Calif., attacks in December that killed 14.
What may be even more disturbing than siblings as terrorists is the possibility that, in the future, a parent and child may work together in yet another evolution in jihadism.
Experts are still examining how often uninvolved family members may be aware of terrorist’ plotting. A 2014 study in The Journal of Forensic Sciences analyzed the behaviors of 119 “lone-wolf” terrorists and found that in nearly two thirds of the cases, family and friends knew the person wanted to commit an act of violence. But in some cases, relatives are strongly opposed: The American terrorist known as the Unabomber, Ted Kaczynski, for instance, was finally caught and convicted because his brother, David, alerted the authorities to his suspicions.
Little is yet known about the relationship between the Bakraouis, who are of Moroccan origin and grew up in Laeken, a working-class neighborhood in Brussels, not far from the Royal Palace. Their father, Jamal el-Bakraoui, is an observant Muslim and a retired butcher, according to Marcelline Mertens, a neighbor.
Ms. Mertens recalled the brothers as ordinary teenagers, not especially religious, who then disappeared from the neighborhood about five or six years ago. During this period, they were separately convicted of crimes including carjacking and engaging in a shootout with the police.
Ms. Bloom, the author who estimated that up to 30 percent of members of terror groups share family ties, warned that extremists were now trying to recruit entire families in Europe, portending the possibility of “Right now, we are seeing a lot of siblings carrying out these attacks,” she said. “The trend we are anticipating is parent and child.”