REALITY MONITORING AND THE JUDGMENT OF TH E TRUTHFULNESS OF ACCOUNTS - AN EXPERIMENTAL-STUDY

How can we discriminate whether or not an account of an event reflects a factual experience or has simply been invented? To meet this proble m, in forensic credibility assessment content criteria have been devel oped which supposedly help to differentiate truthful from deceptive ac counts. The reality monitoring approach is presented as a theoretical basis to rest this assumption. According to this theory internally ima gined and externally experienced accounts differ systematically. Can s imilar differences be found in accounts of events and can these differ ences be reliably detected by other judges? If yes, will the differenc e between experienced and invented accounts be reduced with increased preparation time? These questions were addressed in a 2x2x2 experiment al design in which truthfulness (invented vs. self-experienced) and pr eparation time (immediate vs. one week) were systematically varied. Se x of subject was used as a third categorical variable. One hundred sub jects wrote each a true and an invented story in counter-balanced orde r, with one week time to think about the second account. The 200 stori es were judged with a modified version of the Memory Characteristics Q uestionnaire (MCQ) which was adapted for use with external judges. Mul tivariate analyses of variance and multiple discriminant analyses show ed that true and invented stories can be reliably discriminated on the basis of some of these criteria. Contrary to expectation, some of the se differences were noticeable only after a one week delay. A Brunswik ian lens model analysis showed a relatively high correspondence betwee n cue utilisation and cue validity. Results are contrasted with common sense psychological assumptions and social psychological research on t he detection of deception and with the results of studies investigatin g the validity of criteria used in forensic credibility assessment.