A new report from the Government Accountability Office (GAO) addresses one the programs the TSA uses in airport security checks, called Screening of Passengers by Observation Techniques (SPOT). The program employees 3,000 "behavior detection officers" at 176 airports. They are trained to look for 94 signs of stress in passengers waiting to go through security checks. Display a certain number of them, and you'll be pulled out for further screening and questioning. The SPOT program went into effect in 2007. How's it working out?
For the report, GAO auditors looked at the outside scientific literature, speaking to behavioral researchers and examining meta-analyses of 400 separate academic studies on unmasking liars. That literature suggests that "the ability of human observers to accurately identify deceptive behavior based on behavioral cues or indicators is the same as or slightly better than chance (54 percent)." That result holds whether or not the observer is a member of law enforcement.
It turns out that all of those signs you instinctively "know" to indicate deception usually don't. Lack of eye contact for instance simply does not correlate with deception when examined in empirical studies. Nor do increases in body movements such as tapping fingers or toes; the literature shows that people's movements actually decrease when lying. A 2008 study for the Department of Defense found that "no compelling evidence exists to support remote observation of physiological signals that may indicate fear or nervousness in an operational scenario by human observers."
Despite the academic literature, the TSA actually began testing the SPOT program in 2003—not with an eye toward finding out if it worked, but with an eye toward seeing if it was practical to run in a major airport. In 2007, the program went live and travelers underwent screening. Once the program was set up in 2007, the TSA did hire an outside consultant to evaluate the system's effectiveness. The resulting study, published in 2011, found some effectiveness in using the SPOT criteria. Due to various weaknesses in the study design and implementation, however, GAO doesn't dub it a reliable guide to evaluating SPOT.
That "some effectiveness" does not mean terrorists identified, but an increase in finding people carrying drugs or skirting immigration laws. Read more about the SPOT program at Ars Technica. -via Digg