Lara Warmelink: Using the IAT to Detect Deception about Intentions

Duration: 17 mins 38 secs

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Created:	2015-09-28 17:53
Collection:	Decepticon 2015
Publisher:	University of Cambridge
Copyright:	Dr S. Van der Zee
Language:	eng (English)
Keywords:	Deception; Implicit Association Test; Concealed Information Test; Reaction Time;


Abstract:	The Implicit Association Test (IAT) can be used as an indirect lie detection test. Sartori et al. (2008) found that participants can respond faster to sentences about autobiographical events when the response key for such a sentence is the same key as for sentences that are true (congruent) compared to when the response key is the same for sentences that are false (incongruent). Agosta et al. (2011) showed that this effect is also present when the sentences are about intentions rather than autobiographical events. In these studies, the IAT sentences were the same for all participants and written beforehand by the experimenters. A consequence of this was that the sentences were relatively generic (e.g. Tonight I plan to sleep in my bed). In the current study we wanted to investigate whether the IAT could be used to determine participants’ deception about their own, self- described intentions. We asked participants to describe their intentions for after the study. Participants were then interviewed about this intention and were asked to complete the IAT, with sentences taken from their description of their intention. Half of the participants were asked to lie and describe the same false intention in the interview and on the IAT. The participants described their lie to the experimenter before the interview, so the sentences about their false intention could be added to the IAT. Preliminary results suggest that truth tellers were significantly faster (891 ms) in the congruent condition than liars (1026 ms) (p < 0.001). In the incongruent condition, no significant differences between truth tellers (1930ms) and liars (1806 ms) were found (p = 0.07). Full analysis (mixed effect models) will be provided at the conference, as well as a discussion of the results.

Abstract:

The Implicit Association Test (IAT) can be used as an indirect lie detection test. Sartori et al. (2008) found that participants can respond faster to sentences about autobiographical events when the response key for such a sentence is the same key as for sentences that are true (congruent) compared to when the response key is the same for sentences that are false (incongruent). Agosta et al. (2011) showed that this effect is also present when the sentences are about intentions rather than autobiographical events. In these studies, the IAT sentences were the same for all participants and written beforehand by the experimenters. A consequence of this was that the sentences were relatively generic (e.g. Tonight I plan to sleep in my bed). In the current study we wanted to investigate whether the IAT could be used to determine participants’ deception about their own, self- described intentions. We asked participants to describe their intentions for after the study. Participants were then interviewed about this intention and were asked to complete the IAT, with sentences taken from their description of their intention. Half of the participants were asked to lie and describe the same false intention in the interview and on the IAT. The participants described their lie to the experimenter before the interview, so the sentences about their false intention could be added to the IAT. Preliminary results suggest that truth tellers were significantly faster (891 ms) in the congruent condition than liars (1026 ms) (p < 0.001). In the incongruent condition, no significant differences between truth tellers (1930ms) and liars (1806 ms) were found (p = 0.07). Full analysis (mixed effect models) will be provided at the conference, as well as a discussion of the results.

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