Cross my heart and hope to die...

Telling lies is a pervasive human trait and most people fail to detect they are being lied to, research shows.

For most people, telling nose-stretchers is daily behaviour. According to researcher Aldert Vrij of the University of Portsmouth, on average people lie to 34 per cent of everyone with whom they have contact, about two fibs a day. Studies show 83 per cent of job applicants provide untruthful information; 90 per cent of people lie to get a date. Married individuals lie in one-of-ten interactions with spouses.

According to Jeffrey Hancock of Cornell University, 37 per cent of lies are told during phone conversations, 27 per cent face-to-face and 21 per cent via instant messaging.

E-mails are the vehicle of choice for many liars. Research by Zachary Birchmeier at Miami University indicates "bogus self-representation" is especially common in Internet communications, and that "high status" people are most likely to fib in e-mails.

"Liars want to be able to assure themselves and others that there is something honest about what they are saying...some wisp of truth," explained researcher Bella de Paulo of the University of California. "The best liars are people who don't feel badly about (lying)."

That is why 75 per cent of liars say they would repeat their lies under the same circumstances.

A propensity to lie is "an evolved feature of the human mind," says David Smith of the New England Institute for Cognitive Science and Evolutionary Biology.

Telling lies works because most people cannot detect when they are being told untruths. Research by de Paulo and Charles Bond of Texas Christian University shows people can correctly detect about 54 per cent of the lies they are told.

"Rates of detection vary little from study to study," the researchers agree. "In particular, people regard their interactions with partners as honest."

De Paulo attributes minimal lie-detection capabilities to a lack of "polygraphs, brain sensors or other bells or whistles to help them figure (lies) out."

Several studies show police officers and others with experience in interviewing people are better at ferreting out liars. A 2002 study showed police officers, on average, detect liars about 65 per cent of the time; some individual officers detect 90 per cent of all lies they are told, others only 30 per cent.

Research by Maureen O'Sullivan of the University of San Francisco indicates about one person in 1,000 is a natural lie-detection "wizard", capable of discovering fibs "almost every time" by means of a combination of cues.

According to Vrij, liars often have one or more of the following traits: speech hesitations, changes in voice pitch, blinking, scratching or rubbing body parts, finger gestures, shrugging and shifting body position.

Liars often give fewer details, and use fewer words (often one-word answers) in replying to questions.

Lies vary in magnitude: "white" lies, self-serving lies, actual blatant deceit and concealing-of-information lies.

According to studies at Queen's University, people most often tell self-serving lies to strangers and "harsh truths" are most often given by e-mail.

"False positive" lies, such as those regarding compliments on clothing or food quality, are up to 20 times more prevalent than lies regarding guilt, the research shows.

Robert Alison is a zoologist

based in Victoria, B.C.

Republished from the Winnipeg Free Press print edition February 27, 2010 H6