Effects of segmentation patterns on the perception of deception

Subjects viewed videotapes of truthful and deceptive messages. Channels presented were either face or body with or without speech. Subjects were instructed to segment each message into either large, medium, or small units; following the segmentation of a message, subjects rated its truthfulness. Results showed that subjects who organized the behavior into small units perceived the messages as more truthful than those who organized the behavior into either medium or large units. In addition, when speech was available, accuracy of lie detection was highest when the behavior was segmented into medium units; when speech was not available, accuracy of lie detection was highest when the behavior was segmented into small units. The effects of observation set on the perception of deception were discussed.