investigate the lying & truth telling
behaviours of suspects in high stake
situations (generates real lies &
truths)
Participants
Type of Sampling
opportunity sampling
16 police suspects
13 Males, 3 Females (4 Juveniles. {one 15 yr old, three 13 yr olds]
15 Caucasian, 1 Asian
Variables
IV(s)
8 Coded Behaviours
Annotations:
> Gaze Aversion (number of times suspect looks away from interviewer)
> Eye Blinks (frequency of blinks)
> Head Movements (frequency of head movements, up & down, side to side)
> Illustrators (frequency of arm/hand gestures while talking)
> Self-Manipulators (frequency of scratching neck/wrist)
> Hand/Finger Movements (frequency of moving the hand and fingers without moving the arm)
> Speech Disturbances (Frequency of saying things like "ahh", "umm", unfinished sentences, repetition of words/sentences, stuttering, sentence changes.
> Pauses (duration of noticeable pauses)
DV(s)
Lying/Truth telling behaviours
Method/Design of Study
Procedure/Technique
Type of Experiment
Natural Experiment (Quasi)
Results
Annotations:
> Increase in Gaze Aversion
> Decrease in Hand/Arm Movements
> Increase in
Conclusion
indicators of lying are an increase in pauses and a decrease in blinking.
Evaluation
Strengths
If participants are unaware that they
are being observed, they are more likely
to behave naturally which makes the
findings valid.
Annotations:
The suspects were unaware that the recordings would be analysed for lying/truth telling behaviours. They were more likely to be showing natural behaviour. This makes the findings more valid.
High Ecological Validity
Weaknesses
If participants are unaware that
they are being observed, the study
goes again ethical guidelines,
including informed consent &
deception
Annotations:
Suspects were unaware that the recordings would be analysed and they were not asked for informed consent to be used in the study. They were deceived. Therefore the study goes against ethical guidelines.
Situational variables are difficult to
replicate, therefore it is difficult to
know whether it is IV directly affecting
DV or an uncontrolled situational
variable.