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

A test of skill

Some more

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)

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

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

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

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.

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

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

Processes

• Demeanor

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.

Processes

• Consistency– Correspondence – consistency with external facts

• Appears to operate in a linear fashion

• As inconsistencies accumulate more deception judgments made

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

A Basic Process Model

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

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

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

Test 2

The Facts:The victim is a Female, Hispanic, and 23 years old.The item stolen is a Black, JanSport backpackNo weapon was used

The other ones

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

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

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

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