| Description |
The present mock crime study investigated whether the accuracy of an ocular-motor deception test (ODT) that directly asks if the person committed illicit acts differs from the accuracy of an ODT that indirectly asks if the person provided false answers on a questionnaire about those illicit activities. Guilt, statement type, relevant issue, and completion of a pre-ODT questionnaire were manipulated in the present study to assess their effects on ocular-motor and behavioral measures of deception. Half the subjects were guilty of taking $20 from a secretary's wallet, and the other half were innocent. All subjects were told that some subjects took an exam from a professor's office, but in actuality, no one committed that crime. Three-fourths of the subjects completed a pre-ODT questionnaire that asked about their involvement in the crimes. Subjects answered 48 true/false items five times while their eye movements and pupil diameters were recorded. Half of the guilty and innocent subjects answered test items that directly asked if they committed the thefts. The remaining subjects were asked if they falsified information about the crimes on the pre-ODT questionnaire. Guilty subjects showed the largest pupil diameter while reading the cash items. For direct items, a discriminant function of four ocular-motor measures correctly classified 95% of innocent subjects and 83% of guilty subjects. For indirect items, the discriminant analysis of three ocular-motor measures correctly classified 79% of innocent subjects and 58% of guilty subjects. Results suggest that indirect test items are less effective than direct ones. |
