Health

Liars Take 30% Longer to Reply

by Terri Potratz | January 27, 2009 at 02:44 pm

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A new lie detection procedure shows that liars take an average of 30% longer to respond when they are lying compared to when they are telling the truth:

Aiden Gregg, a psychologist at Southampton University who developed the timed antagonistic response alethiometer (Tara), found that in 85% of cases interviewees were slower at faking answers than when telling the truth. Gregg believes that lying takes longer because it involves more complex cognitive activity.

The Tara test involves answering a series of questions displayed on a computer screen as quickly as possible by tapping responses on a keyboard.The programme records how long it takes each individual to answer and uses an algorithm to analyse the results. Gregg said he built the test because he suspected that criminals were finding increasing ways to hide their dishonesty.

The test was developed in part because polygraph tests, which measure physiological changes during a question and answer period, are not accurate for lie detection and often end up implicating innocent individuals.

Experts say the average person tells three lies in a 10- minute conversation, plus a wide range of minor omissions, exaggerations and bluffs. The average listener, however, can only spot fibs around 54% of the time, according to Gregg.

The new lie detection test may prove useful to government agencies such as the Department of Homeland Security as a supplementary tool to spot practiced and habitual liars.

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