Effects of Guilt, Disbelief, and Assessed Lie-Truth Telling Abilities on Physiological Responses in the Guilty Action Test

This experiment used a mock crime procedure in which 100 participants were randomly assigned to four experimental conditions in a 2 × 2 factorial design. Two guilt conditions (guilty and informed innocents) were crossed with two human interrogation feedback conditions (believed and not believed). The Guilty Action polygraph test was administered several days after the mock crime and the human interrogation. Along with the common dependent polygraph measures (electro dermal, respiration, and cardiovascular measures), self-assessments of the ability to tell lies and to tell the truths convincingly, were gathered. Results showed enhanced responses to the critical items for all three physiological measures. Respiration responses significantly differentiated between guilty and informed innocent participants. No significant guilt effect was obtained for electro dermal and cardiovascular responses. The feedback manipulation failed to affect all three physiological responses. Informed innocent participants who rated low their ability to tell the truth convincingly elicited larger electro dermal responses to critical items than high raters. Guilty participants who rated high their lie telling ability showed larger electro dermal responses to critical items than low raters. Further research on the association between self-assessment of lie and truth telling abilities and physiological responsivity in the Guilty Action Test is recommended.