The impact of thin(ner) slicing on deception detection

Abstract

I examined whether the length of thin slices (i.e., observations of behavior less than five minutes) affected deception detection. Participants (N = 262) were randomly assigned to one of seven exposure length conditions (i.e., 5-second, 10-second, 15-second, 20-second, 25-second, 30-second, or full-length clips). They attempted to detect the deception of 12 speakers. Participants’ ability to discriminate between truth- and lie-tellers did not significantly differ across conditions. Response biases, decision-making processes, and response times were similarly unaffected by exposure. However, there was some indication that confidence differed for truth- and lie-tellers across exposure lengths. That is, significant differences in confidence for truth- and lie-tellers were observed in the 5- and 10-second conditions, although the direction of effects differed. Therefore, while researchers can be confident that the decision to use long or short thin slices will not affect deception detection, it could affect participants’ confidence in those judgments.