The GSR in the detection of guilt

Abstract

How accurate is a lie detector in determining guilt? "Forty-nine male college students, after random assortment into four groups, were required to enact one, both, or neither of two mock crimes. All were then given a guilty knowledge test, employing the GSR, which used six standard questions relating to each of the two crimes. A simple, objective, and a priori scoring system was used to determine guilt. Forty-four or 89.8% of the Ss were assigned to their correct group, against a chance expectancy of 25%. Considering the crimes separately, all Ss innocent of a crime were correctly classified, while 44 or 50 interrogations of guilty Ss gave guilty classifications, a total of 93.9% correct classification against a chance expectancy of 50% . . .. Detection of guilty knowledge . . . is demonstrably capable of very high validity in those situations where it can be used." (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1959 American Psychological Association.