BUFFALO, N.Y. -- Mark Frank has spent two decades studying the
faces of people lying when in high-stakes situations and has good
news for security experts.
"Executing Facial Control During Deception Situations," a new
study he co-authored with former graduate student Carolyn M.
Hurley, PhD, reports that although liars can reduce facial actions
when under scrutiny, they can't suppress them all.
Frank, PhD, a professor of communication at the University at
Buffalo, supervised and co-wrote the study with lead author Hurley,
now a research scientist at the U.S. Transportation Security
Published earlier this year in the Journal of Nonverbal
Behavior, the study
examined whether subjects could suppress facial actions like
eyebrow movements or smiles on command while under scrutiny by a
It turns out subjects could to a degree, but not completely and
The results are derived from frame-by-frame coding of facial
movements filmed during an interrogation in which participants,
some lying, some telling the truth, were asked to suppress specific
parts of facial expressions. Hurley and Frank found that these
actions can be reduced, but not eliminated, and that instructions
to the subjects to suppress one element of expression resulted in
reduction of all facial movement, regardless of their implications
Despite these findings, the majority of the 60 study
participants reported believing that they had controlled all facial
movement and had remained "poker faced" during the
"Behavioral countermeasures," says Frank, "are the strategies
engaged by liars to deliberately control face or body behavior to
fool lie catchers. Until this study, research had not shown whether
or not liars could suppress elements of their facial expression as
"As a security strategy," he says, "there is great significance
in observing and interpreting nonverbal behavior during an
investigative interview, especially when the interviewee is trying
to suppress certain expressions."
for a news interview in which Frank describes elements of his
Hurley and Frank say prior research in Ironic Process Theory
(IPT) has shown that when individuals are required to monitor their
thought patterns so as to suppress a thought or image, the process
places that thought or image into their monitoring memory, enabling
it to intrude more frequently into their regular memory.
Hurley and Frank say this is even more likely to occur when one
is telling a lie because, as research has shown, lying raises the
cognitive load and reduces the ability to successfully and
naturally engage in interaction with others.
The study involved 33 female and 27 male undergraduate subjects
who were introduced into a crime scenario in which they were
randomly assigned to either take (lie) or not take (tell the truth)
a pair of movie tickets from an envelope.
They were then interviewed about the theft of the tickets by an
experienced but neutral interrogator blind to the experimental
conditions. Participants were told they would be rewarded if they
convinced the interrogator of their honesty and punished if not.
All denied taking the tickets.
Prior to the interview some subjects were specifically
instructed to suppress upper face activity (manifested through
eyebrow-raising actions) and lower face activity (manifested
"Although these facial movements are not necessarily guaranteed
signs of deception," says Frank, "expression suppression --
regardless of its validity as a clue to deception -- is clearly one
of the more popular strategies used by liars to fool others. What
we didn't know was how well individuals can do this when they are
lying or when they are telling the truth.
"Based on the research literature on the nature of facial
expressions of emotion, the neuroanatomy of the face, emotional
suppression research and IPT research," he says, "we correctly
predicted that in interrogations in which deception is a
possibility, individuals would be able to significantly reduce
their rate and intensity of smiling and brow movements when
requested to do so, but would be able to do so to a lesser degree
when telling a lie.
"And, since the lower face (and smile in particular) is easier
to control than the upper face, we predicted that our subjects
would more greatly reduce their rate of smiling, compared to their
rate of brow movement, when requested to suppress these actions,"
he says, "and that turned out to be the case as well. We can reduce
facial movements when trying to suppress them but we can't
eliminate them completely.
"Whether we are dealing with highly skilled and motivated liars
who have practiced their nonverbal expression in high-stakes
scenarios, or untrained individuals who learn from a television
program about a particular brow or lip movement that is allegedly a
telltale sign of deception," Frank says, "the findings of this
study have important implications for security settings."
Frank is a social psychologist who conducts research on human
non-verbal communication -- particularly micro-expressions --
focused on truth-telling. He founded the Communication Science
Center at UB in 2005 and his work, funded through major
foundations, is recognized and employed by defense, science and
security agencies throughout the world.
The University at Buffalo is a premier research-intensive public
university, a flagship institution in the State University of New
York system and its largest and most comprehensive campus. UB's
more than 28,000 students pursue their academic interests through
more than 300 undergraduate, graduate and professional degree
programs. Founded in 1846, the University at Buffalo is a member of
the Association of American Universities.