AICE Psychology: Suspects, Lies, and Videotape: An Analysis of Authentic High-Stake Liars Samantha Mann; Aldert Vrij; Ray Bull
Terms in this set (11)
Examine the behaviour of liars who have lied spontaneously of their own
volition, in high stake situations (police suspects in custody)
To determine if there are systematic behavioral indicators to distinguish
between those who are telling lies and those who are telling the truth.
To determine if cognitive load or attempted behavioural control causes
changes in behavior related to lying or telling the truth
16 police suspects (13 males and 3 females); (4-juveniles aged 13-15 years) Type of sampling: Opportunity Sampling (in this case they were those who were in the videos police collected)
Type of experiment/method
Veracity (truth or lie)
Eight behavioural categories
GAZE AVERSION: number of seconds in which the participant looked away from the interviewer
HEAD MOVEMENTS: frequency of head nods (upward and downward movements were counted as a separate nod) & head shakes (similar to head nods, each sideways movement was counted as a separate shake)
HAND/FINGER MOVEMENTS: any other movements of the hands or fingers without moving the arms
SPEECH DISTURBANCES: frequency of saying "ah" or "mmm," etc. between words, frequency of word and/or sentence repetition, sentence change, sentence incompletion, stutters, etc.
PAUSES: number of seconds where there is a noticeable pause in the monologue of the participant, when the suspect actually stops between words for a period of approximately 0.5 seconds or more, stopping the free flow of conversation for a period of time whilst the suspect thinks of the next word
Lying was accompanied by a decrease in blinking F(1,15) =7.04, p <.05; Increase
in pauses, F (1,15) =4.43, p <.05; No other significant differences emerged
One hour long footage with 65 clips (27 truths and 38 lies); For each participant
minimum number of clips were 2 (one truth & one lie) and a maximum of eight
clips (>3 truths & < 5 lies); The total length of clips per participant was analyzed
on participant level and not on clip level; Total length of clips per participant
varied from 41.4 to 368; Length of clip & length of response varied but not
significant in terms of analysis of behavior
(A structured observation is where the researchers design a type of coding scheme to record the participants' behaviour.
Structured observations generally provide quantitative data. Coding schemes are ways of categorising behaviour so that you can code what you observe in terms of how often a type of behaviour appears.)
The most reliable indicators of deception were blinking and pauses, where the
majority of participants paused longer (81%) and blinked less (81%) while lying.
The findings suggest that there existed large individual differences in deceptive
behavior challenging the simplistic view of deceptive behavior.
Findings support for the cognitive overload process in explaining deceptive
behavior, as both fewer blinking and longer pauses are possible indicators of
HIGH LEVEL OF ECOLOGICAL VALIDITY
and HIGH LEVELS OF CONTROL
Sample size was small therefore can not generalized, can be considered unethical