...first practice to deceive.

If you hanker to improve your lie-catching skills, try gearing up for the challenge by concocting some of your own falsehoods, asserts Bella M. DePaulo of the University of Virginia in Charlottesville. Studies in her laboratory indicate that people identify videotaped liars more accurately after first fibbing to an experimenter.

This strategy may sensitize participants to the motivation and demeanor of liars, DePaulo theorizes.

"People know more about the differences between lies and truths than they realize," she contends. "Unconscious knowledge about deception often doesn't feed into judgements about deception."

DePaulo and University of Virginia colleague Kathy L. Bell find that the proper motivation helps activate unconscious insights into deception. In one experiment, men holding traditional views of masculinity identified videotaped liars more accurately after an experimenter told them that the ability to detect deceptions would help them in business and other competitive situations. Similarly, women holding traditional views of femininity performed better on the test after the experimenter told them that lie-catching aptitude would help them in interpersonal relationships.

The improvements in deception detection charted by DePaulo and others usually prove modest, notes Paul Ekman of the University of California, San Francisco. DePaulo agrees, but says even small boosts to judgmental accuracy can make a big cumulative difference across different social situations.

Expert lie detection requires more than a close personal acquaintance with deception, Ekman asserts. For example, criminal psychopaths show no better accuracy at identifying videotaped liars than do college students, he says.

Most people may learn to ignore behaviours that others refuse responsibility for, from obvious gaffes -- such as burping in public -- to the subtler intricacies of lying, Ekman argues.