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An Ecological Approach to Deception Detection J. Pete Blair, Ph.D., Department of Criminal Justice, Texas State University Tim R. Levine, Ph.D., Department.

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Presentation on theme: "An Ecological Approach to Deception Detection J. Pete Blair, Ph.D., Department of Criminal Justice, Texas State University Tim R. Levine, Ph.D., Department."— Presentation transcript:

1 An Ecological Approach to Deception Detection J. Pete Blair, Ph.D., Department of Criminal Justice, Texas State University Tim R. Levine, Ph.D., Department of Communication, Michigan State University

2 A test of skill

3 Some more

4 40+ Years of the Traditional Approach The primary theories are leakage based (Ekman, Zuckerman, Burgoon, DePaulo) Based on these theories, the primary concern is identifying leakage and people’s ability to detect it. The outcomes of this type of research have been: –Few behaviors reliably indicate deception, and those that do tend to exhibit small effect sizes (DePaulo et al., 2003) –People don’t know the cues to deception –People are only slightly (4%) better than chance at detecting deception and accuracy clusters normally around the mean (Bond & DePaulo, 2006) –There is little variance in judge ability, but enormous variance in sender credibility (Bond & DePaulo, 2008) –Training has a small effect (4%) on accuracy (Frank & Feeley, 2003)

5 40+ Years of the Traditional Approach The results of the traditional approach are quite modest And surprising! Why? –Lack of realism (low stakes, sanctioned lies)? –Myopic focus on leakage? In our opinion, there is a need for a new paradigm

6 Looking for Exceptions Asch (1956) Line length studies Milgram (1969) Obedience to authority Park et al. (2002) How people really detect lies “Reid” based series of studies Hartwig et al. (2005 & 2006) – Strategic Use of Evidence Why are these different? We think that the answer is Context

7 Context All communication occurs in a context It is difficult to communicate without knowledge of the context Most deception detection experiments are designed to strip context away because of a leakage focus Context could provide information which assists in deception detection We call these “Content in Context Cues” –Contradiction –Normative –Idiosyncratic

8 Our Big “Content in Context” Study 6 Samples of Participants in 8 Runs 3 sets of videos 2 basic conditions (context/no context) –Context 176 unique judges who made 2422 judgments 75% accuracy (1% SE) –No Context 237 unique judges who made 3132 judgments 57% accuracy (1% SE) Clearly context matters! Blair, J.P., Levine, T.R., & Shaw, A.S. (2010). Content in context improves deception detection accuracy. Human Communication Research, 36, 423-442.

9 Moving Toward Ecology Our thinking is strongly influenced by Brunswick and Gigerenzer –A Darwinian understanding of how psychological processes develop –Processes are adapted to environment –Both the process and the environment must be considered (2 blades of the scissors) –Procedure Identify process(es) Test environments to identify limits Modify environments to assist the functioning of process This is the direction that our research program is currently taking

10 Processes Motive –Absent a motive for deception, deception judgments are not made –Levine, T. R., Kim, R. K., & Blair, J. P. (2010). (In)accuracy at detecting true and false confessions and denials: An initial test of a projected motive model of veracity judgments. Human Communication Research, 36, 81–101. Demeanor –Tim has developed an 11 item demeanor scale –It predicts up to 82% of the variance in judgments –Still under review

11 Processes Demeanor

12 Processes Consistency –Coherence – consistency of a statement with itself or other’s statements People adhere to this, but it doesn’t work very well Granhag, P. A., & Stromwall, L. A. (2000). Deception detection: Examining the consistency heuristic. In C. M. Breur, M. M. Kommer, J. F. Nijboer & J. M. Reintjes (Eds.), New Trends in Criminal Investigation and Evidence II (pp. 309-321). Antwerpen: Intersentia. Stromwall, L. A., Granhag, P. A., & Jonsson, A. (2003). Deception among pairs: "Let's say we had lunch and hope they will swallow it!". Psychology Crime & Law, 9, 109-124.

13 Processes Consistency –Correspondence – consistency with external facts Appears to operate in a linear fashion As inconsistencies accumulate more deception judgments made

14 Processes Consistency –Correspondence Hartwig, M., Granhag, P. A., Stromwall, L. A., & Vrij, A. (2005). Detecting deception via strategic disclosure of evidence. Law and Human Behavior, 29, 469-484. We also have a piece under review

15 A Basic Process Model

16 Environments We haven’t done much specific work in this area, but –Motive seems to be very general –Demeanor as well –Consistency (both coherence and correspondence) require extra information to utilize, but seem to be utilized when present Only motive and correspondence seem to generally enhance deception detection accuracy We are starting to work on how these processes operate in conjunction with each other

17 Modifying Environments We consider the specific questioning utilized to be an environmental modification We call this “Question Effects” A question is effective when it causes a truth-teller to act like a truth-teller, a deceiver to act like a deceiver, or both Acting like a truth-teller or a liar is defined based upon the previously discussed processes

18 Question Effects Correspondence Example – Hartiwig’s (2005 &6) SUE. If the suspects are questioned in a way that gives away what the interviewer knows, the suspect makes his or her statement consistent with the information. Deception detection accuracy is reduced. Coherence Example – Vrij’s et al.’s (2008) unexpected questions. Pairs of liars will practice their story and be more coherent than truth-tellers. Asking unexpected questions undoes this and makes coherence useful. Demeanor Example – Levine & Blair’s (under review) question effects. Changed question from “why should I believe you” to “what will your partner say?” –Below chance accuracy with the first and above with the second

19 Test 2 The Facts: The victim is a Female, Hispanic, and 23 years old. The item stolen is a Black, JanSport backpack No weapon was used

20 The other ones Background information: The trivia test is extremely difficult. Most people who scored 3 or more probably cheated.

21 Expertise A debate over expertise in detecting deception has gone on for some time One camp has tested large numbers of people using distinct sets of videos to find a few “experts” (who score 80% or better on a subset of trials) One camp has meta-analyzed the data and come to the conclusion that the is no evidence for expertise Taking an ecological approach, we argue that there ought to be expertise, but that this expertise is situated within a particular environment We are seeing if we can develop “experts” (without training) this summer

22 Summary The dominant traditional approaches to deception detection research have produced modest results Adopting an ecological approach seems to provide a flexible way forward This approach considers the process in the environment Three parts –Identification of processes –Testing of processes in environments to identify limits –Modification of environments to allow the processes to function effectively

23 Summary Processes –Motive –Demeanor –Coherence –Correspondence Environments –These processes should be available in most investigative contexts –They do not all function well in standard environments Modification of environments –Question effects have been shown to impact the functioning of the processes in common environments –These effects can be good or bad


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