AI for lie detection

Question 1

Give examples of the practical applications of lie detection

Answer 1

Criminal investigations, insurance fraud, terrorism etc

Question 2

What kind of lie detectors are in use now? (4)

Answer 2

Voice stress analysis (pitch, tremors), language analysis, physiological measures such as pitch and heart rate are used to construct polygraph tests which are used in a number of countries such as the US, UK and Belgium, screening passengers by observation at the airport after 911.

Question 3

What do each of these have in common?

Answer 3

Cool acronyms and name and these methods often claim extremely high levels of accuracy however these claims have rarely been reflected in empirical research.

Question 4

Give an example of a experimental design meant to measure lying in the lab

Answer 4

Participants are split into a lying and non-lying group. Liars leave the lab after receiving instructions and ‘commit a crime’ e.g steal an exam. Controls leave and do an innocent assignment. They then come back to second blind experimenter who interviews them and tries to figure out whether they are lying or telling the truth, both are instructed to give the same story.

Question 5

Give some critiques of this kind of paradigm

Answer 5

• There is nothing at stake when ‘lying’

- lower motivation to attempt to hide a lie

Question 6

What is a benefit of this kind of lab study?

Answer 6

They have control and know with absolute certainty who is lying and who is not.

Question 7

Describe the alternative to lab research

Answer 7

Field research, for example going somewhere where polygraphs are being done, requesting the charts with physiological recordings from the police and then looking for a criterion which determines whether the polygraph was correct or not (e.g whether the person is convicted or not.)

Question 8

What is the cost of this kind of research

Answer 8

You never know for certain who is lying and who is telling the truth

Question 9

What problems arise with the existence of both these lines of research?

Answer 9

Often only lab or only field research is considers in meta analyses and literature reviews and the other on is ignored, this can lead to two very different conclusions.

Question 10

Aside from claiming high accuracy and fancy acronyms, what underlying mechanism do these lie detection methods have?

Answer 10

Stress and distress

Question 11

What is the problem with this underlying mechanism?

Answer 11

Many different variables can heighten our arousal, emotional valence and stress and cause a false positive. Questions about a sensitive case for example would cause more distress for someone accused than control questions.

People may also lie without feeling stress or arousal.

Question 12

What is an alternative approach to detecting lying?

Answer 12

Lying is more difficult than telling the truth, it ‘demands invention, dissimulation, and a good memory.’ This is backed up with research through methods such as self report and reaction time (takes longer to lie).

Question 13

What have brain imaging studies regarding lying revealed?

Answer 13

Study involved one group stealing an exam, one stealing 50 euro and then being asked about each crime. Activity in the right inferior frontal cortex, which has been associated with inhibition, has been associated with lying. This could suggest that the first intuition is to tell the truth, but they have to inhibit that and tell a lie instead.

Question 14

Is lying always more difficult than telling the truth?

Answer 14

No, lying can be developed almost as a skill so that it becomes just as easy or easier than telling the truth.

Question 15

If you want to use a cognition based approach to lie detection, what steps are advised to go about it?

Answer 15

1. Use cognitive clues; e.g reaction time
2. Elicit cognitive cues (as they are often hard to detect otherwise)
   3.

Question 16

How good are different people at lie detection

Answer 16

Very bad, people generally score at chance level even policemen, psychologists etc

Question 17

How could you elicit cognitive clues?

Answer 17

The metaphor used is like an exercise bike with different resistance levels, you can't observe the resistence levels just by watching them cycle but if you increase the speed or wait a long time it will start to become apparent. Some ways to elicit the cognitive cues are as follows:
Reverse order
Unexpected questions
Keeping eye contact
Drawings
Multiple interviewers
Secondary task
Second language 
Model statement
Information Protocol

Question 18

Why are unexpected questions useful?

Answer 18

People keeping up a lie can repeat a lie to a question continuously and can become accustomed to it (e.g Lance Armstrong), asking an unexpected question (e.g who packed your bags) forces them to think about the answer.