Few topics in psychology get as much attention as the telltale signs of deception. The emphasis on this topic has intensified tenfold over the last decade in response to terrorism, and a great deal of research has been initiated by Homeland Security and police departments as a means to inform and train their personnel.
One of the leading researchers in this field is UCLA professor of psychology R. Edward Geiselman. His studies have served as a the basis for training thousands of detectives, intelligence officers, police officers, and military personnel.
The sidebar benefit of all this research for us (in addition to the benefits of greater security) is that we can learn to nail liars in the act. A recent paper by Dr. Geiselman and three of his students in the American Journal of Forensic Psychiatry summarizes findings from 60 studies on detecting deception.
The most reliable indicators of lying, according to Geiselman, include:
Geiselman also notes that when deceptive people attempt to cover up these typical reactions to lying, they become more obvious liars. The reason is that a liar's "cognitive load" is already high from manufacturing a story and trying to delivery it convincingly. Geiselman instructs his trainees on ways to increase this cognitive load to push the liar over the edge. Ways of doing this include:
How hard is it to catch liars? Very, according to Geiselman and Dr. Paul Ekman, another researcher who has devoted his career to identifying the signs of deception. In previous studies, Ekman found that without training, the average person's abilty to identify a liar is roughly the same as chance.