Before you tell Dawn Sweet that your dog ate your homework, you should know that this Iowa State U. lecturer in psychology and communication specializes in detecting deception.
With a doctorate in communication, Sweet has worked with the Department of Defense and the FBI to detect hostile intent through body language and facial expressions.
She currently works as a consultant for the Department of Homeland Security, where she applies her expertise to airport security.
Fox’s TV show “Lie to Me” is based in large part on the research similar to that of Sweet and her colleagues Mark Frank, from the University of Buffalo, and Paul Ekman, professor emeritus of psychology at the University of California, San Francisco.
Sweet’s job is very similar to the show, but of course with much less glamorous, she says.
“They have million-dollar budgets and they have technology that doesn’t exist,” Sweet said.
In fact, Sweet spends hours looking at videos, searching for signs of deception. It is very tedious work, as she must analyze 30 different frames per second. She looks at expressions of emotion as markers of deception, or “hot spots.”
Sweet consults with the Transportation Security Administration, helping to train employees to look for a checklist of behaviors in flyers. Flyers showing signs of several of these behaviors are viewed as potential threats and interrogated.
During an investigation, Sweet first tries to establish a behavioral baseline for each suspect. In other words, she figures out exactly how that person acts normally.
Establishing the suspect’s normal behavior is very important, because, Sweet said, “Everyone’s baseline is going to be different.”
She says a lot of fidgeting may indicate deception for one suspect, but not necessarily for another person who has a tendency for such movements. She then looks for micro-expressions, which are involuntary facial expressions occurring in humans when they attempt to suppress emotions.
“Our emotions are controlled by a very primitive part of the brain that we don’t have control over,” Sweet said.
Sweet said there are 44 muscles in the face and 10,000 different combinations of movement, but even skilled liars can slip up.
“We’re only interested in certain combinations of emotions,” Sweet said.
There are seven basic universal expressions: happiness, sadness, fear, contempt, disgust, surprise and anger. Sweet said when interrogating a suspect, she looks for the last four in particular.
“It’s pretty labor intensive,” Sweet said, “and it takes a long time to really become good at that.”
Sweet first became involved in this research as a graduate student working with Frank at Rutgers University and has been involved in detecting deception ever since. After earning her doctorate, she accepted a teaching position at Iowa State.
She is currently working on two research projects.
One of these projects focuses on the development of an assessment for identifying adversarial behavior in the context of placing improvised explosive devices.
The other deals with developing a behavioral coding system for mutual orientation and attention in the interaction of people with autism.
She says the biggest challenge of her profession is getting money for her research.
“After 9/11, money came pouring in for research,” Sweet said. “Whenever these sorts of horrific events happen, suddenly there’s new interest in our research.”
She said events like Sept. 11 drive home the importance of completing research that could potentially prevent these tragedies
As for her life outside Homeland Security, Sweet said she doesn’t wake up in the morning planning to catch people in a lie, but “it’s hard to turn it off.”
With a smile, she admitted, “Yes, I have caught my students lying.”