Detecting Deception Steven Van Aperen Australian Polygraph Services 23rd November 2006

All truths are easy to understand once they are discovered; the point is to discover them. Galileo Galilei

It is very difficult for the average person to lie.

Why do people deceive?  Conditioning  To hide the truth  To protect themselves

Types of lies  “I wasn’t involved in match fixing, I always played to win”  “I studied psychology at University”  “I did not have have sexual relations with that woman Monica Lewinski”?

Lying in Employment  One third admitted to lying on CV  47% lied about leisure pursuits  28% about their salary  19% about personal skills & qualities  3% about criminal record

Lying in Employment  18% think its necessary to lie on CV’s  One fifth believe employers don’t check  6% say that they would just say they made a typing error!  30% admit to lying but managers think only one in ten (10%) CV’s contain false information  36% believe it is the responsibility of employers to check accuracy

What to look for:  Paralinguistic Changes  Non-Verbal (Body Language)  Verbal (Lying with words)

What to look for:  Tone  Pitch  Rate  Response Latency

Non-Verbal Behaviours  Look for clusters of behaviour  Be aware of hand to face gestures

Non-Verbal Behaviours  Research indicates that up to 80% of communication is non-verbal

Non-Verbal Behaviours Remember our body language will often betray the spoken word.  (Yes/No)

The eyes have it, or do they?

The Qualifying Statement The subjects response may be literally true because they deny some narrow issue of the interviewer’s question

Lying by generalisation Often a person will lie by generalisation. This occurs when a person may be vague or non-specific in response to a question.

Verbal Responses Truthful people answer specific questions with direct, spontaneous and realistic words

Examples of how people deceive

Analysing content and structure

PN: They’re now with you are they? MB: Yeah I’ve actually transported the female, Sally. MB: Um ah yes she’s asl um she’s half asleep anyway Police negotiator (PN) and Martin Bryant (MB) 28 th April, 2000 re Sally Martin

PN: She’d be very frightened and she’s an elderly lady. MB: Yeah I got her upstairs so PN: So you can imagine that the trauma that she’s going through MB: She’ll be fine I mean they could eat well Police negotiator (PN) and Martin Bryant (MB) 28 th April, 2000 re Sally Martin

PN: Are you prepared to let me talk to Sally MB: Ah unfortunately um she’s down stairs with David now I’ve got um another chap with me. Police negotiator (PN) and Martin Bryant (MB) 28 th April, 2000 re Sally Martin

Past & Present Tenses  Singular person past tense vs present tense  Look for changes between past and present tense

 It was Monday night. I was walking down the road. It was getting dark when a man ran up and punched me in the face  It was Monday night. I was walking down the road. It was getting dark and a man runs up and punches me in the face.

Susan Smith 25 th October, 1994

“My children wanted me. They needed me. And now I cant help them.” Susan Smith (mother) “They’re OK. They’re going to be home soon.” David Smith (father)

Shapelle Corby “ I didn't put it there” (4 times) “This is not mine” “I'm innocent” (twice) “I didn't put it there that’s the bottom line I didn't put it there.” “They're not my drugs. I didn't put them there.” “I’m innocent.”

John Myles Sharpe plea for the return of Anna Kemp & Gracie Sharpe Did you kill your wife and daughter? “I haven't harmed my wife or my daughter” “The child belongs with the mother”

Summary  Learn to understand and read body language  Are questions being answered or is the person being evasive, omissive or dismissive?  Observe what the person is doing as well as listening to what they are saying

Summary  Look for changes between past and present tenses  Look for ‘clusters’ of behaviour  Remember we lie by omission rather than commission  PRACTICE!