Case Study 1- Analysis Authentic High Stake Liars Flashcards
Who were the researchers of this study and in what year was it held?
Mann
Vrij
Bull
2002
Context/ Background
What did early research have?
Had mixed results
Context/background
What happened to the design of these studies
The designs did not give same results - Unreliable
Context/background
Why was this ?
They were done in a laboratory where participants didn’t really see the importance in telling the truth or lying as there were no consequences .
So how would they know if someone was lying?
Aim
Who did they investigate ?
Investigated lying behaviors of SUSPECTS that were in police custody- controlled
Aim
Why is it controlled?
It is a high stake situation and real life.
Suspects have something to lose.
Hence if they would lie, they would loose their freedom.
Therefore it leads real lying
Methods:
What was the method they used to get the videoclips?
Researchers contacted detectives from Kent police station in the United kindom.
And were asked if they could collect videoclips that would include both truth and lying.
Methods:
What did researcher do?
Within these videos they went through forensic evidence or independent witness statements.
Methods:
What happened to the videoclips ?
These videos were recorded onto other videotapes.
Became a one hour video with 16 suspects
Method:
How many clips were they?
What was the minimum ?
What was the average length?
65 clips were used- 27 truth 38 lies
Each participant hand the minimum of two clips.
Length was raged between 41 to 368 seconds
Method:
What were the eight behaviors?
S- self manipulations
I- illustrators
P- pauses
S- speed disturbances
G-gaze aversion
B-blinking
H- hand / finger movements
H- head movements
Method:
What was the format, that these eight behaviors were changed in order for lies and truths to be directly compared ?
For:
Gaze aversions
Pauses =
Total length of coded behaviors / total length of time of truthful clips X 60
Hand
Head
Blinks =
Frequency of H H B / total length of time of truthful clips X 60
Total number of speech disturbances / total number of words spoken X 100
Participants:
How many suspects were there ?
What were there ages?
What were the crimes of the participants ?
16 suspects 13 males 3 females
Aged 13 up to 65
Crimes were: Attempted Rape- 1 Arson- 2 Theft- 4 Murder- 4
Procedures :
What was done?
Two independent observers were brought into code video footage.
- They do not know what the study was about.
- nor if it was truth or lies
- Coded 8 behaviors
Procedures:
What did the observers do ?
Observer 1- coded all clips
Observer 2- coded randomly 36 clips out of 16 suspects.
Procedure:
Why do they decide to follow this procedure?
- Inter-rated reliability.
- Is the check of the amount of agreements between observers
- example : Observer 1- sees if data is reliable
Observer 2- rechecks the data that observer 1 checked to see if it was done correctly. - Dealing with sensitive nature
- the less people that know about these clips the better. As by showing we may be disrespecting the suspects rights.
Results:
What type of data?
These were quantative data.
Displayed on a tally chart.
Results:
What was found and concluded?
Lying was accompanied by a decrease in blinking in 81% of suspects.
E.g. truths 23.56. Lie- 4.94
Lying was accompanied by an increase in pauses in 81% of suspects.
E.g. Truth 3.73 and lie 4.94
Yet, there were individual differences.
As in other behaviors there were no other significant differences between when they lied and told the truth.
Conclusion
Most reliable indicators of lying in a high stake situation were a decrease in blinking and an increase in pauses.
These findings go against what was found before, being fidgeting and avoiding contact
Advantages of this authentic high take liars study.
Validity -
video tapes consist of genuine police interviews.
Study is measuring authentic high stake liars
Double blind design
- suspects did not know behavior was being analyzed.
- Two observers did not know what they were looking for.
Ecological validity -
- Participants did not know they were being observed in terms of lying or telling the truth, therefore will display more NATURAL and REAL behavior
Minimal bias from researchers
- all behaviors were counted
- data was statistic and factual- scientific
- inter reliability confirms this.
Disadvantages of authentic high stake liars?
Difficult to repeat
- Observation techniques were used from police interviews. Therefore police could change the sense of the video clip if asked for more clips.
Ethics
-Suspects did not give concent to the study.
