Guilty Knowledge versus Innocent Associations: Effects of Trait Anxiety and Stimulus Context on Skin Conductance.

Abstract A simulated lie detection procedure was used to investigate skin conductance responsivity among self-reported skin responders. Subjects were grouped according to reported trait anxiety as measured by Lykken's Activity Preference Questionnaire and then engaged in either a mock crime or a neutral activity. The “crime” gave subjects “guilty knowledge,” and the neutral task provided “innocent associations” to relevant stimuli imbedded in each scenario. Subjects were then interrogated using Lykken's Guilty Knowledge technique. Anxiety classification, guilty vs. innocent treatment, and type of stimulus were manipulated in a 2 × 2 × (2) factorial design. Results for differential responsivity scores showed significant main and interaction effects. Low-anxiety subjects showed almost no effects, but highly anxious subjects responded strongly in the “guilty” rather than the “innocent” treatment. Contrary to previous findings, results showed a substantial—but qualified—relationship between self-reported anxiety and electrodermal responsivity. Also, the Guilty Knowledge technique with rank scoring yielded 97.5% correct classification.