Validity of the guilty-knowledge technique: The effects of motivation

Abstract

48 VOLUNTEER COLLEGE STUDENTS DIVIDED INTO 12 GROUPS TOOK PART IN AN EXPERIMENTAL INVESTIGATION OF DETECTION OF A SIMULATED CRIME. FOR EACH OF 12 CRIMES, 3 SS WERE HIGHLY MOTIVATED TO COMMIT THE CRIME; 1 SUCCEEDED, 1 ATTEMPTED BUT FAILED, AND 1 DID NOT MAKE AN ATTEMPT. THE 4TH S INTERROGATED FOR EACH CRIME WAS AN INNOCENT CONTROL. MOTIVATION FOR DECEPTION (HOPE OF REWARD) WAS HIGH ($25-$50) FOR 1/2 OF THE CRIMES AND LOW (< $1) FOR THE OTHER 1/2. DETECTION OF DECEPTION USING A POLYGRAPH RECORDING OF GSR AND THE GUILTY-KNOWLEDGE TECHNIQUE RESULTED IN CORRECT CLASSIFICATION OF 92% OF "GUILTY" SS AND 100% OF "INNOCENT" SS. NO SIGNIFICANT DIFFERENCES WERE FOUND DUE TO LEVEL OF MOTIVATION FOR DECEPTION. RESULTS ARE DISCUSSED IN TERMS OF THEIR RELATIONSHIP TO SIMILAR STUDIES AND ACTUAL CRIMINAL INVESTIGATIONS. (PsycInfo Database Record (c) 2025 APA, all rights reserved)