“There are tools where they build a world in a bottle. They put down every single mosque, river, camel, and school in, say, Saudi Arabia. Then they have millions of software agents who each have desires, grievances, all these ­different variables. They go about their little lives and then you ask a question: What if we build a McDonald’s in Mecca? Does this lead to more people joining terrorist groups or not?”

—Gary Ackerman, Director of the Center for Terrorism and Intelligence Studies

Photo: Bill Cramer/Wonderful Machine

Barry Silverman: peers deep into the heart of darkness to find what makes terrorists tick.

Barry Silverman pecks at the keyboard, and suddenly his computer ­monitor is showing him the view down a scary-looking alley in the Bakhara market in Mogadishu, Somalia. On the big screen, Silverman sees the market through the eyes of his avatar, a software soldier. It’s a detailed scene, on a par with what you’d see in today’s best first-person shooter video games: in the market’s narrow lanes, militiamen scurry about, checkered headdresses flapping. It has rained recently, and the gray masonry walls of buildings surrounding the market are water stained. The streets are empty except for some abandoned cars and the smoldering wreckage of two helicopters. Silverman’s cybertrooper is part of a virtual squad replaying the scenario described famously in Mark Bowden’s 1999 best seller, Black Hawk Down, in which U.S. Army Rangers attempted a rescue after fighters loyal to warlord Mohamed Farrah Aidid shot down two U.S. UH-60 choppers.

The Ranger that Silverman controls wanders only a few steps toward the downed helicopters before he encounters a suicide bomber who blows them both to bits.

Silverman, an electrical and systems engineering professor at the University of Pennsylvania, in Philadelphia, restarts the simulation. As his Ranger avatar scans the scene, Silverman describes the attributes of each character—or synthetic human agent—he encounters. He knows them all intimately, their motives, emotions, and physiol­ogies, as well as their political, religious, and moral leanings. He should; he and his group created every last one of them.

Through the Ranger’s gunsight we see a Somali woman dressed in flowing blue robes and matching head scarf walking with a militia­man clad in an ankle-length white garment. Raising his voice above sporadic gunfire and the crunch of boots, Silverman is explaining that some of his graduate students spent an entire semester studying the behavior of Somali women and their value systems.

He points to the screen as the woman allows the man to hold her in front of him. “This is not scripted,” he says. “Somali women will act as shields for their men….She is acting according to her values, her physiology, her stress, which are tuned to a person in that culture, and she of her own volition does the things that you see unfold here.”

Silverman, whose sleepy brown eyes and deliberate speech belie a dry wit, gets the man in the crosshairs of his Ranger’s gunsight. “He’s already upset, because we’ve been over there trying to kidnap the whole leadership of his tribe for a while now. We’re not as innocent as I’m playing here; I’m already sort of labeled….” Gunshots ring out, bullet casings clink on the ground. “They’re looting…and now I’m trying to chase them away.” Suddenly, chaos. An explosion rocks the market, followed by a spray of gunfire. “He’s shooting back at me, and it’s hard for me to aim at him because he’s got the woman there”—pop, pop, and then a moan as Silverman drops the militiaman. “Oh,” he says, surprised by his own marksmanship. “I got him.”

The woman slinks away. “She’s now leaving, because she has no reason to obey him anymore. He’s dead.”

The mere fact that his agents improvise based on individualized sets of complex rules instead of acting according to a rigid script would be enough to make Silverman a rock star among game developers. In fact, the Bakhara market simulation looks like a first-person shooter because it’s based on the Unreal Tournament game engine from Epic Games, which renders the scenes and drives the interactive environment. Nonetheless, though his characters are brought to life by a commercial game engine, the software that gives his characters their individual identities is generations beyond anything you’ll find in a video game today. Silverman’s agents, along with those being developed by a few other teams, are about the closest a computer comes to simulating the thought processes of a real person. Similar work is being done by The Sims cocreator John Hiles at the Naval Postgraduate School, in Monterey, Calif., and Jonathan Gratch and Stacy Marsella at the University of Southern California’s Institute for Creative Technologies, in Marina Del Ray.

“This is really at the cutting edge of computational behavior modeling,” says Gary Ackerman, who, as director of the Center for Terrorism and Intelligence Studies, a think tank in San Jose, evaluates these kinds of programs for various U.S. government agencies. “They have been more successful than I thought they could have been, pretty much frighteningly so at some points.”

Silverman’s group is one of several driven by a hypothesis that seemed far-fetched even five years ago: that computers equipped with the right software can give vital insights into the minds and motives of terrorists and the structure and critical links in their organizations. The work is part of a larger effort, much intensified after 9/11, in which the U.S. intelligence community, in particular, is looking for better ways to identify terrorists, determine their capabilities, and predict where and when they will strike. Different forms of the software are aimed at military officials, who are already using such programs to train officers and troops, and at intelligence analysts, who are finding that the shadowy, shifting organizations they must study are so complex and unstable that keeping track of all the variables without computer help is increasingly unrealistic. The hope is that one day an intelligence analyst sitting at a desk thousands of miles from Jakarta or Jalalabad will be able to make preternaturally good guesses about who is likely to commit violent acts, and to advise policy-makers on specific ways to prevent an attack.