PAPER REVIEW PRANJAL SAXENA Y9424 To catch a liar: The effects of truthful and deceptive testimony on inferential learning Robert Montague, Daniel J. Navarro, Amy Perfors, Russell Warner, & Patrick Shafto Department of Psychological and Brain Sciences, University of Louisville School of Psychology, University of Adelaide IN TRODUCTION AN D AREA OF WORK: Decep?on is an act of crea?ng a false belief in the mind of someone else. This paper aims to study decep?on involved in conceptual learning processes where by individuals build up informa?on solely on the basis of tes?mony provided by others. The informers can be split into two categories, helpful and decep?ve. Decep?ve informers either lie outright, or can be economical with the truth, providing misleading informa?on. Learners have to rely on this informa?on , however they possess the op?on of verifying tes?mony in both the cases. The previous studies in this area have focussed on picking up verbal , non verbal and visual clues to iden?fy decep?on. Acoording to Bond and DePaulo,2006, a meta analysis shows that we are more adept in catching audible than visible lies and people appear more decep?ve when there is an external mo?va?on to believe them. Ekman & O'Sullivan, 1991 conducted experiments involving police officers, judges and psychiatrists where they were asked to dis?nguish a truthful experience by a person from a false one. They showed that the ability to dis?nguish truthful statements from lies is purely based on chance, and people performing be?er, o?en were able to pick up different behavourial clues and possessed specific skill set. This paper though,deals with recognising decep?ve interac?ons over ?me, where different visual and non visual clues are absent and the learners must solely rely on the tes?mony of the informers , learners try to infer whether the informer is truthful or decep?ve through verifica?on, and as a result, choose to con?nue asking for informa?on or learn on their own. The authors primarily aim to answer three ques?ons through their study: 1. "First, how does the informa?on provided by helpful and decep?ve informants differ? 2. Second, how o?en do learners verify the informa?on provided, and does this differ based on whether the informant is decep?ve or not? 3. Third, how effec?vely do people recognize when they are being deceived, given only the content of the tes?mony" -ques?ons are directly cited from the paper,page 2 column1, second last paragraph. EXP ERIMEN T: For the purpose of the study a game was designed where, pairs of par?cipants were divided into 2 broad groups: coopera?ve and compe??ve. Within each subgroup, individuals were randomly assigned the role of an informer or a learner. An interface was built where the objec?ve of the exercise was that the learners should iden?fy a rectangular area in a broad white field space. Coopera?ve and compe??ve informers provided helpful or misleading hints respec?vely in the form of interior or exterior points of the rectangle. The learners also had the op?on to 'dig' where they could click on a point and find out if it is an interior or exterior point, which also gives the op?on of verifying the tes?mony. Learners had five chances to gather informa?on for a par?cular field and twenty fields were tested with the same informer, thus giving them a ?me space to infer on credibility of informa?on by the informer. Some sample images of the interface(directly cited from the paper,page 1 right column) are shown below: picture1.JPG picture2.JPG RESULTS OBTAIN ED: Broadly, the learners' rectangle differed from the informers' rectangle more in the compe??ve casethan the coopera?ve case: (graph cited from paper, page 3, column 1) PIC TURE3.JPG However as an answer to the first ques?on, the coopera?ve hints aimed at providing the points of the edges, whereas compe??ve informers chose to mislead by providing points distant from the exterior or comfortably placed at the interior. This informa?on, although being truthful dsnt help the learner to reproduce the rectangle. Therefore ,it is interes?ng to note that they chose to mislead the learner by saying the truth rather than lying outright. For the second ques?on, the results show that the learners chose to verify about 30% of the hints in both cases with no significance escala?on in the compe??ve case. This might be because, learners might not want to lose on a chance by checking the hints, rather use all the opportuni?es to establish the rectangle by digging themselves Finally, on the basis of a ra?ng by the learners, it was seen that they could iden?fy decep?ve informers from the helpful ones even when there was no change in the number of verified points. The learners based their judgement on the nature of hints received, for example, corner points enabled faith on the informers, and they ended up asking for more hints. DISCUSSION: A sparkling conclusion that the paper provides is that decep?ve informants more o?en than not choose to provide misleading truthful informa?on rather than lying outright. For example, a murder suspect might get away by providing a mix of informa?on to the interviewing officer, where he puts enough truthful tes?mony which the officer can verify , thus maintaining trust, however adding enough evasive informa?on which does not enable the inves?ga?on to proceed on the right track. Based on the results of the conducted experiment, the learners iden?fy decep?ve informants on the judgement whether the tes?mony has proved helpful or not, instead of verifica?on at every step. Therefore from the inves?ng officer's perspec?ve, it would be ideal for him to compare the tes?mony of the witness with perfect tes?mony : ideal informa?on that would allow him to solve the case. Any discrepancies would indicate the fact that the suspect is trying to mislead and is involved in the crime. Another aspect that the results highlight is that learners put more trust on those informers who intend to give hints that the learners have preconceived to be helpful. Therefore learners form an expecta?on related to helpful hints which might enable them to locate the rectangle. This is in accordence with the work of Bonawitz et al., 2009; Xu & Tenenbaum, 2007 who showed that learners tend to form a narrow outlook over purposefully sampled informa?on and do not look at all the a?ributes which they would have for a randomly sampled informa?on.
