The Use of Physiological Measures to Detect Deception in Juveniles

This study examined the effectiveness of a directed lie polygraph test in a juvenile population (9-15 years of age). Eighty-four juveniles were tested regarding their possible involvement in the tearing of a page from a book. A computer model for classifying adults as truthful or deceptive used physiological measures to determine the participant’s involvement in the “crime.” The adult-based model accurately identified 72.6% of the juveniles and was more accurate at identifying innocent than guilty participants. A separate classification model, derived from the juvenile data, correctly classified 73.8% of the juveniles. Although the accuracy rates were not as large as those reported for adults, there was a significant difference in the patterns of physiological responses for guilty and innocent juveniles. The modest accuracy rates with juveniles in the present study are discussed in relation to limitations in the design and the potential impact of the observed low reliability of the juveniles’ physiological responses. Future directions in assessing the validity of the polygraph to detect deception in juveniles and the impact of cognitive developmental changes on detectability are discussed.