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
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