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Interviewing to Detect Deception (grant RES-000-23-0292)

Aldert Vrij

Samantha Mann

Ron Fisher

Becky Milne

Ray Bull

Objectives

We are pleased to report that the project went according to plan. We have carried

out all four experiments as outlined in the proposal. In the original proposal we refer to

four experiments, whereby Experiments 1 to 3 consisted of two parts, an interview part

and a lie detection part. Throughout this report we will refer to these two parts as separate

experiments, and we will therefore discuss the results of seven experiments.

Background

In their police manual, Inbau, Reid, Buckley, and Jayne (2001) 1 present three

strategies aimed at detecting deceit. These are: (i) the focusing on visual cues strategy;

(ii) the Baseline Method strategy; and (iii) the Behaviour Analysis Interview strategy. In

this ESRC project, we examined to which extent those three traditional methods could

discriminate between truth tellers and liars. However, we were pessimistic about their

1 What Inbau et al. (2001) have to say about lie detection is important because their manual is influentialand commonly used by police and military interrogators (Gudjonsson, 2003).

To cite this output:Vrij, Aldert (2007). Interviewing to Detect Deception: Full Research Report.ESRC End of Award Report, RES-000-23-0292. Swindon: ESRC

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success, and therefore developed a new strategy to detect deception, called the cognitive

load approach, which we tested in the present project.

Traditional Methods to Detect Deceit

Although in interview settings police detectives could concentrate on both the

suspects behaviour and speech, police manuals typically focus more on behaviour

(visual cues) than on speech related cues to deceit. For example, when Inbau et al. (2001)

discuss the visual (e.g., eye contact, movements), vocal (e.g., response latency, response

length) and verbal (e.g., evasiveness) cues that they claim are related to deception

(Chapter 9), the visual cues section is the largest section. This is remarkable because

deception research has demonstrated that most visual cues, including most of those

discussed by Inbau et al. in Chapter 9, are not reliable indicators of deceit (DePaulo,

Lindsay, Malone, Muhlenbruck, Charlton, & Cooper, 2003). In contrast, vocal cues

(DePaulo et al., 2003) and verbal cues (Masip, Sporer, Garrido, & Herrero, 2005; Vrij,

2005) are more reliable cues to deception. Concentrating too much on visual cues will

therefore hamper lie detection due to the lack of diagnostic cues an observer could rely

upon. Concentrating on visual cues will further encourage the use of stereotypes,

especially when speech is ignored and only nonverbal cues taken into account, as

observers have little to go on (Bond & DePaulo, 2006). Those views are related to how

liars behave (e.g., liars show gaze aversion and fidget) rather than how truth tellers

behave. As a result, concentrating on the visual cues may result in a lie bias, that is the

tendency to judge people as liars. We tested in this project the hypothesis that

concentrating on visual cues will impair lie detection accuracy and will increase a lie bias

(Experiment 7).


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The basic assumption behind the Baseline Method strategy (examined in

Experiments 5 and 6) is that different individuals show different nonverbal and verbal

responses. This assumption is correct. Some people typically make many movements,

whilst others do not; some people are very talkative, others are not, some tend to look

someone else into the eyes when they speak, other do not, etc. (DePaulo & Friedman,

1998; Vrij, 2000, 2004). In order to control for those individual differences, the Baseline

Method strategy recommends that police officers examine a suspect's natural, truthful,

verbal and nonverbal responses during the small-talk part at the beginning of the

interview, and compare these responses with those shown by the suspect during the actual

interview (Inbau et al., 2001). Differences in behaviour could then be interpreted as signs

of deceit.

This approach is prone to resulting in incorrect judgements because an

incongruent comparison is made. Not only do different people behave differently in the

same situation ( inter personal differences), the same person also behaves differently in

different situations ( intra personal differences) (DePaulo & Friedman, 1998). The

baseline method as proposed by Inbau et al. (2001) fails to take those intrapersonal

differences into account. Small-talk and the actual investigation are fundamentally

different situations. Small-talk conversations are low-stake situations where the suspect's

responses are unlikely to have any negative consequences. The investigative part of the

interview, on the other hand, is a high-stake situation where the suspect's responses are

intensely scrutinised and his/her reactions may easily heighten suspicion. Suspects are

probably aware of this and therefore, not surprisingly, both guilty and innocent people

tend to show different behaviours during small-talk compared to the actual interview


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(Vrij, 1995, 2006). We thus predicted that the baseline method as proposed by Inbau et

al. would not be effective in discriminating between liars and truth tellers, but were

hoping that a baseline method that did take the intrapersonal differences into account

would be useful.

The Behaviour Analysis Interview (Inbau et al., 2001, examined in Experiments

1 and 2) is a predetermined standardised list of 15 questions, starting with the question:

"What is your understanding of the purpose of this interview?", followed by questions

such as: "Who would have had the best opportunity to commit the crime if they had

wanted to?" Despite its name, behaviour analysis interview, Inbau et al. (2001) predict

differences in both nonverbal and verbal responses between liars and truth tellers.

Regarding the nonverbal responses, Inbau et al. (2001) assume that liars feel less

comfortable than truth tellers in the police interview situation. As a result, guilty suspects

are more likely to cross their legs, shift in their chair, look away and perform grooming

behaviours while answering the BAI questions. Verbal responses should also

discriminate between truth tellers and liars, because, according to Inbau et al. (2001),

interviewees' answers will reflect their different attitudes towards the investigation. Liars

are thought to be less helpful in the interview and do not show the appropriate level of

concern about being a suspect, whereas truth tellers are more likely to offer helpful

information, and show an expectancy to be exonerated.

There is reason to doubt that Inbau's BAI hypothesis will promote effective

discrimination between truth tellers and liars. The basic premise underlying the nonverbal

responses, that liars feel less comfortable than truth tellers in a police interview, is not

universally accepted by the scientific community (National Research Council, 2003). For


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instance, DePaulo et al. (2003) and Ekman (1985) have argued that in situations where

the consequences of not being believed are severe, not only liars but also truth tellers will

be concerned about not being believed.

Compatible with this view, but refuting Inbau's hypothesis, DePaulo et al.'s

(2003) meta-analysis of nonverbal correlates of deception demonstrated that liars were no

more likely than truth tellers to look away, shift in their chair, cross their legs or make

grooming gestures. In fact, eye contact is not related to deception, and, in direct contrast

to Inbau et al.'s (2001) assumptions, liars tend to decrease rather than increase their

movements (DePaulo et al., 2003). The tendency for liars to decrease their movements

may reflect greater cognitive load borne by liars. Lying is often cognitively more difficult

then telling the truth (DePaulo et al., 2003; Ekman, 1985), and greater cognitive load

results in a neglect of body language, reducing overall animation (Ekman, 1985). Liars'

decreased movements may also be partly attributable to impression management. Liars

are likely to be even more concerned about the impression they make on others than truth

tellers (DePaulo et al., 2003; Vrij, 2000; Kassin, 2005; Kassin & Norwick, 2004). Like

liars, truth tellers are also keen to be seen as truthful. However, truth tellers typically do

not think that this will require any special effort or attention (DePaulo et al., 2003). In

other words, truth tellers more often take their credibility for granted (DePaulo et al.,

2003; Kassin, 2005; Kassin & Norwick, 2004). As a result, liars are more inclined than

truth tellers to refrain from exhibiting excessive movements that could be construed as

nervous or suspicious (DePaulo & Kirkendol, 1989).

This latter impression management explanation (liars put more effort into making

a convincing impression than truth tellers) also raises doubts about the view that guilty


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suspects will be less helpful than innocent suspects. This was the premise underlying the

expected differences in verbal responses to the BAI questions between guilty and

innocent suspects. Both guilty and innocents suspects will probably believe that being

helpful will make a positive impression, but perhaps guilty suspects will be even keener

to make such an impression, because they will take their credibility less for granted.

The combined cognitive load/impression management hypothesis directly

opposes Inbau et al. (2001), and hence predicts that (a) liars' answers should be more

helpful than those of truth tellers and (b) liars' nonverbal responses should appear more

relaxed than those of truth tellers.

The Cognitive Load Approach

Since we had our doubts about the capability of the traditional methods to

successfully discriminate between liars and truth tellers, we proposed a new lie detection

approach (Vrij, Fisher, Mann, & Leal, 2006). This approach is based on the premise that,

in most interviews, lying is cognitively demanding. Several aspects of lying contribute to

this increased mental load. First, formulating the lie itself may be cognitively taxing.

Second, as mentioned above, because liars are typically less likely than truth tellers to

take their credibility for granted liars will be more inclined than truth tellers to monitor

and control their demeanour in order to appear honest to the lie detector. Monitoring and

controlling ones own demeanour should be cognitively demanding. Third, because liars

do not take credibility for granted, they may monitor the interviewer's reactions more

carefully in order to assess whether they are getting away with their lie (Buller &

Burgoon, 1996). Carefully monitoring the interviewer also requires cognitive load.

Fourth, liars may be preoccupied by the task of reminding themselves to act and role-play


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(DePaulo et al., 2003), which requires extra cognitive effort. Fifth, liars have to suppress

the truth while they are lying and this is also cognitively demanding (Spence et al., 2004).

Finally, while activation of the truth often happens automatically, activation of the lie is

more intentional and deliberate, and thus requires mental effort (Gilbert, 1991; Walczyk,

Roper, Seemann, & Humphrey, 2003).

The premise that lying is cognitively demanding has support from a number of

sources (Vrij, Fisher, Mann, & Leal, 2006). For example, participants in a mock-suspect

experiment directly assessed their own cognitive load during interviews and reported that

lying is more cognitively demanding than truth telling (Vrij, Semin, & Bull, 1996); police

officers who watched videotapes of real life police - suspect interviews thought that the

suspects were thinking harder when they lied than when they told the truth (Mann & Vrij,

2006); and deceiving is associated with activating executive 'higher' brain centres such as

the prefrontal cortex (Spence et al., 2004).

Lie detectors could exploit the differential levels of cognitive load that liars and

truth tellers experience by introducing protocols that introduce additional cognitive load.

Liars, whose cognitive resources will already be depleted by the more demanding act of

lying, will have fewer cognitive resources left over to satisfactorily address the additional

cognitive demand, which will result in more substantial differences between liars and

truth tellers and, subsequently, should facilitate discriminating between liars and truth

tellers. A method to increase cognitive load is recalling an event in reverse order (Fisher,

Brennan, & McCauley, 2002).

We examined the impact of recalling a story in reverse order on lying and lie

detection in Experiments 3 and 4. Based on our assumptions that (i) lying is cognitively


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more demanding than truth telling, and (ii) recalling a story in reverse order is cognitively

more demanding than telling a story in chronological order, we expected liars to show

more cues to cognitive load than truth tellers, particularly when they were recalling their

stories in reverse order (Experiment 3). In Experiment 4 we showed police officers a

selection of those interviews, and examined their ability to discriminate between liars and

truth tellers in the reverse order and control conditions. Based on the outcome we

anticipated in Experiment 3, we expected truth and lie detection to be superior in the

reverse order condition.

Finally, we examined in what type of interview setting our cognitive load

approach would be most appropriate (Experiment 1). In their analysis of videotaped

police interviews with suspects, Moston and Engelberg (1993) observed two different

styles of starting an interview: Accusatory style and information-gathering style. In the

accusatory style, the interviewer confronts the suspect with an accusation (e.g., "I think

you have committed the crime", "Your reactions make me think that you are hiding

something from me"). In the information-gathering style, the interviewer does not

confront the suspect with an accusation, but rather asks an open question allowing

suspects to describe their actions in their own words (e.g., "Describe in as much detail as

possible what you did between 3pm and 4pm this afternoon?"). We expected

information-gathering interviews to be more appropriate for our cognitive load approach

than the accusatory interviews. First, we expected information-gathering interviews to be

more cognitively demanding than accusatory interviews. In an accusatory interview, the

respondents' replies are likely to be simple, short denials of the accusations (" I didn't do

it", "I am innocent", etc.). By comparison, in information-gathering interviews,


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respondents are encouraged to provide detailed and lengthy statements about their

activities, which should make their task more cognitively demanding. Second, we

expected information-gathering interviews to result in more verbal cues to deception than

accusatory interviews. The more words there are in the suspect's response, the more

verbal cues there should be to discriminate between liars and truth tellers, simply because

words are the carriers of verbal cues. As information-gathering interviews will generate

longer answers, they will contain more verbal cues to deception than will accusatory

interviews.

Methods

In Experiments 1, 3, and 5 participants (undergraduate students) lied or told the

truth. In Experiments 1 and 3 they lied or told the truth about taking money out of a

wallet (see the two attached articles for full details of the experimental design); in

Experiment 5 they lied or told the truth about having prior knowledge about the number

of dots that appeared on a screen in a count the dots competition. The interviews were

video recorded and the nonverbal behaviours (gaze, gestures (e.g., illustrators,

hand/finger movements and self-adaptors), foot/leg movements, eye blinks, latency

period, pauses, stutters, uhms, speech rate) and speech content (the verbal cues listed in

the Criteria-Based Content Analysis and Reality Monitoring tools) were coded. In

Experiment 1 the participants were interviewed in three different ways (accusatory,

information-gathering, and behaviour analysis interview style) and the impact of the

interview style on behavioural and verbal responses was examined; in Experiment 3

participants recalled their stories in either normal or reverse order; and the impact of this


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instruction on the behavioural and verbal responses were examined; in Experiment 5 the

behaviour and speech content of liars and truth tellers during the target period (guessing

the number of dots on a screen while having (liars) or not having (truth tellers) been

informed the actual number of dots that appeared on the screen) were compared with the

behaviour and speech content shown by the participants during two control periods,

whereby one control period showed more similarity with the target period (estimating the

number of dots on the screen without having prior knowledge) than the other control

period (small talk at the beginning of the interview). In Experiments 2, 4, and 6,

observers (police officers) were shown a selection of twelve interviews (six truth tellers

and six liars) from Experiments 1, 3 and 5 respectively and were asked after each

interview to judge the veracity of the story-teller. In Experiment 7, observers (police

officers) were shown a selection of fourteen clips from interviews of suspects in their

police interviews (data collected from Mann, Vrij, & Bull, 2002). All participants

observed the same clips but one group saw the video with no audio, another group heard

the audio of the clips but saw no video image. The third (control) group saw the video as

normal. In Experiments 1, 3, and 5, 255 undergraduate students participated: 120 in

Experiment 1, 80 in Experiment 3 and 55 in Experiment 5. In Experiments 2, 4, 6, and 7,

290 police officers participated: 68 in Experiment 2, 55 in Experiment 4, 64 in

Experiment 6, and 103 in Experiment 7.

Results

Concentrating on Visual Cues


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The truth accuracy, lie accuracy and response bias (B measured with the Signal

detection Theory approach) of Experiment 7 are presented in Table 1. The higher the B

score, the stronger the lie bias was.


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Table 1. Truth Accuracy, Lie Accuracy and Response Bias (B) as a Function of Medium

Exposure

Condition Truth accuracy Lie accuracy BM SD M SD

Visual + audio (N = 35) .59 .1 .70 .1 .21

Visual only (N = 37) .34 .2 .53 .2 .36

Audio only (N = 31) .63 .2 .69 .1 .11

Truth accuracy, lie accuracy and response bias all differed from each other (all

F s > 3.38, all ps < .05, all eta2

> .07. Posthoc tests regarding truth and lie accuracy

revealed that, as predicted, the participants in the visual only condition achieved lower

truth and lie accuracy rates than the participants in both of the other two conditions.

Posthoc tests regarding the response bias revealed that participants in the visual condition

made more lie judgements than participants in the audio condition. These findings

suggest that observing visual cues results in a lie bias, as we predicted. The fact that a lie

bias in the visual only condition did not result in high lie accuracy is interesting. It

appears that more lie judgements (66%) were made when suspects were telling the truth

than when they were lying (47%). This is probably the result of the inaccurate

stereotypical view that observers have about how liars behave (Vrij, Akehurst, & Knight,

2006). For example, although observers believe that liars make more movements than

truth tellers, research has shown that truth tellers typically move more than liars. As a

result, by concentrating on movements, the livelier participants (e.g., truth tellers) will be

classified as liars.

Baseline Method

Analyses of Experiments 5 and 6 are still in progress. Preliminary results show

mixed support for our hypothesis that having a meaningful baseline will facilitate lie


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detection. In Experiment 5 we first examined the behavioural differences between liars

and truth tellers whilst they guessed how many dots there were on the screen (target

period). At a multivariate level, the analysis did not reveal a significant multivariate

effect, F (13, 41) = 1.18, ns. Univariate tests only revealed one significance: Liars paused

longer ( M = .89 per minute of speech, SD = 1.2) than truth tellers ( M = .30, SD = .6), F (1,

53) = 4.60, p < .05, eta 2 = .08. This analysis resembles the task lie detectors face when

they are required to distinguish between truths and lies when no meaningful baseline is

available.

We then carried out a second analysis. This time we detracted the behavioural

scores from liars and truth tellers during the target period from their behavioural scores

during the meaningful control period. This analysis revealed a significant multivariate

effect, F (13, 41) = 2.10, p < .05, eta 2 = .40. Five significant effects emerged at a

univariate level, comprising illustrators, hand/finger movements, self adaptors, gaze

aversion and blinks, all F s > 2.86, all ps < .05, all eta 2 > 05. For each behaviour, liars

displayed larger differences between the target period and the meaningful control period

than truth tellers: Liars decreased their movements more and showed more gaze aversion

than truth tellers. This analysis resembles the task lie detectors face when they are

required to detect truths and lies when there is a meaningful baseline available. In

summary, when a meaningful baseline was available more cues (five) discriminated

between truth tellers and liars than when such a baseline was not available (one).

In Experiment 6 police officers were shown a sample of the liars and truth tellers

from Experiment 5 either with a meaningful baseline (experimental condition) or without

a meaningful baseline available (control condition). Both groups obtained around a 60%


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accuracy rate. A possible explanation why the experimental participants did not

outperform the control participants is that they misinterpreted the diagnostic cues. The

liars showed a decrease in movements, which is typically found in deception research,

whereas observers widely believe that liars increase their movements. Perhaps

experimental participants will outperform control participants if they are informed

beforehand that liars typically decrease rather than increase their movements. We are

going to test this hypothesis in a follow-up experiment.

Behaviour Analysis Interview

The article concerning the Behaviour Analysis Interview experiment (Experiment

1) is attached, so please see that article for further details (Vrij, Mann, & Fisher, 2006a).

The results revealed that liars were less co-operative and appeared more nervous than

truth tellers. These results were consistent with our cognitive load/impression

management hypothesis in direct opposition to Inbau et al.s predictions. When in a

subsequent lie detection experiment (Experiment 2), police officers were shown those

interviews based on the Behaviour Analysis Interview, they performed no better than

chance in discriminating between liars and truth tellers (Vrij, Mann, Kristen, & Fisher, in

press, this article is also attached).

Cognitive Load Approach: Information-gathering Interview Accusatory Interview

Comparison

When we compared participants experiences during the information-gathering

interviews and the accusatory interviews (Experiment 1) we found, as predicted, that

information-gathering interviews were perceived as more cognitively demanding ( M =

4.23, SD = 1.3) than accusatory interviews ( M = 3.36, SD = 1.5), F (1, 76) = 7.36, p < .01,


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eta 2 = .09 (Vrij, Mann, & Fisher, 2006b). Moreover, information-gathering interviews

resulted, as predicted, in more verbal cues to deceit than accusatory interviews (Vrij,

Mann, Kristen, & Fisher, in press, attached article). The detection of deception

experiment (Experiment 2) did not reveal differences in truth and lie accuracy when the

information-gathering and accusatory interviews were compared (Vrij, Mann, Kristen, &

Fisher, in press, attached article), however, accusatory interviews resulted in more false

accusations (classifying a truth teller as a liar) than information-gathering interviews.

Cognitive Load Approach: The Reverse Order Experiments


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Table 2 reveals the verbal and nonverbal cues that differentiated liars from

truth tellers in the reverse order and control conditions (Experiment 3). The higher the

score, the more frequently the cues occurred. The cues are measured per 100 words

(speech hesitations and speech errors) or per minute of interview (the remaining

cues). As predicted, many more cues to deceit emerged in the reverse order condition

than in the control condition and most of the cues that distinguished liars from truth

tellers in the reverse order condition are signs of cognitive load (all cues except

increase in foot/leg movements and eye blinks).

In Experiment 4, we showed police officers a random sample of these reverse

order and control interviews and examined their ability to detect deceit in those

interviews.

Table 3. Truth Accuracy, Lie Accuracy and Response Bias (B) as a Function of Reverse

Order

Condition Truth accuracy Lie accuracy BM SD M SD

Reverse Order (N = 31) .56 .2 .60 .2 .07

Control (N = 24) .50 .2 .42 .2 -.13

Lie accuracy in the Reverse Order condition was significantly higher than lie

accuracy in the control condition, F (1, 53) = 10.53, p < .01, eta 2 = .17. Lie accuracy in

the Reverse Order condition was significantly above the level of chance, t (30) = 2.68,

p < .05, whereby the lie accuracy in the control condition was significantly below the

level of chance, t (23) = 1.97, p < .05. Although the truth accuracy in the Reverse

Order condition (56%) was also higher than the truth accuracy in the control condition

(50%), this difference was not significant, F (1, 53) = 1.26, ns, eta 2 = .02. The

difference in response bias was not significant either between the two conditions, F (1,

38


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53) = .87, ns, eta 2 = .02. Neither of the two response biases differed significantly from

zero, t s < 1.59, p > .12. In other words, instructing interviewees to tell their stories in

reverse order led to higher lie accuracy without impairing truth accuracy, without

influencing the response bias.

In summary, the project showed that several methods traditionally used by

investigators to distinguish between truths and lies do not work. However, our new

cognitive load approach showed potential. Cognitive load interview protocols are

designed to make information-gathering interviews more demanding for suspects.

This increased demand has a larger impact on liars than on truth tellers because liars

already find being interviewed more mentally taxing than truth tellers. The result is

that cognitive load interview protocols facilitate discrimination between liars and truth

tellers.

Activities

The results of Experiments 1, 2, 3, 4, and 7 have been presented at European

and American Psychology and Law conferences. The lead applicant, Aldert Vrij,gives detection of deception talks worldwide to both practitioners and scholars

(around ten presentations a year) and the results of this ESRC project have a

prominent place in these presentations. Moreover, Vrij is currently updating his

Telling and detecting lies book (originally published in 2000) and the results of this

ESRC project play an important role in the revised version of his book.

Outputs

The project has so far resulted in four publications (Law and Human Behavior

is the most prestigious Psychology and Law Journal):

Vrij, A., & Mann, S. (2006). Criteria-Based Content Analysis: An empirical test

of its underlying processes. Psychology, Crime, & Law , 12, 337-349.

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Vrij, A., Mann, S., & Fisher, R. (2006a). An empirical test of the Behaviour

Analysis Interview. Law and Human Behavior, 30, 329-345.

Vrij, A., Mann, S., & Fisher, R. (2006b). Information-Gathering vs Accusatory

Interview Style: Individual Differences in Respondents' Experiences. Personality and

Individual Differences , 41, 589-599.

Vrij, A., Fisher, R., Mann, S., & Leal, S. (2006). Detecting deception by

manipulating cognitive load. Trends in Cognitive Sciences , 10, 141-142.

One more publication is in press: Vrij, A., Mann, S., Kristen, S., & Fisher, R.

(in press). Cues to deception and ability to detect lies as a function of police interview

styles. Law and Human Behavior .

There are many more publications to come. One paper (Vrij, Mann, Fisher,

Leal, Milne, & Bull) regarding Experiments 3 and 4 has been submitted, and we will

submit a paper regarding Experiment 7 soon. We further received invitations to write

one book chapter about the project (to appear in International developments in

investigative interviewing (Milne, Savage, & Williamson, Eds.), and two entries in theSage Encyclopedia of Psychology and Law (Cutler, Ed.). Experiments 5 and 6 still need

to be written up, as well as the nonverbal data of Experiment 1 and the individual

differences data from Experiments 1 and 2.

Impacts

Throughout this project we worked closely together with the policeconstabularies of Hampshire and Kent and they showed interest in the results. Once

all the data of the project have been fully analysed and written up (we expect this

work to be completed within the next six months) we will contact those constabularies

to discuss the findings. We are planning to discuss the findings also in other

constabularies, and the strong links the co-applicants Milne and Bull have with

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various police constabularies in England and Wales are thereby particularly helpful.

The project has also received interest from several Governments (UK and abroad)

with whom we work on lie detection issues.

Future Research Priorities

We believe that our cognitive load detection of deception approach has

potential and are currently conducting research to refine this approach. Vrij, Fisher,

and Mann received a three-year grant (not from the ESRC) to sponsor these research

activities. The nature of these activities is confidential and cannot be disclosed. Dr

Samantha Mann, who worked as a Research Fellow on the ESRC project, has been

employed as a Research Fellow on this new grant.

Ethics

No ethical considerations have arisen from the project. Students enjoyed

participating because they like to see whether they are good liars. Police officers were

sometimes less enthusiastic, because they did not always see the relevance of the

experiments. The problem is that, as participants allocated to specific experimental

conditions, they lack the overview regarding the aims of the experiments. The

debriefing clarified these issues, but the hypotheses under investigation were

sometimes received with skepticism. Not a single participant, however, withdrew

during the experiments or asked his/her data to be withdrawn after the experiment.Because each experiment demanded so much time from police participants (on

average just over an hour to run) and we generally recruited participants from police

training colleges where courses are highly structured without much free time, it took a

lot of time to accumulate the number of police participants that we did. Therefore we

recruited no more participants then strictly essential to test our hypotheses.

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Confidentiality

Nothing reported in this End of Reward Report is sensitive or confidential.

Number of words: 4996

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References

Bond, C. F., & DePaulo, B. M. (2006). Accuracy of deception judgements.

Personality and Social Psychology Review , 10, 214-234.

Buller, D. B., & Burgoon, J. K. (1996). Interpersonal deception theory.

Communication Theory , 6 , 203-242.

DePaulo, B. M., & Friedman, H. S. (1998). Nonverbal communication. In D. T.

Gilbert, S. T. Fiske, & G. Lindzey (Eds.), The handbook of social psychology (pp. 3-40).

Boston, MA: McGraw-Hill.

DePaulo, B. M., Lindsay, J. L., Malone, B. E., Muhlenbruck, L., Charlton, K.

& Cooper, H. (2003). Cues to deception. Psychological Bulletin , 129 , 74-118.

Ekman, P. (1985). Telling lies: Clues to deceit in the marketplace, politics and

marriage . New York: W. W. Norton & Company.

Fisher, R. P., Brennan, K. H., & McCauley, M. R. (2002). The cognitive

interview method to enhance eyewitness recall. In M. L. Eisen, J. A. Quas, & G. S.

Goodman (Eds.), Memory and suggestibility in the forensic interview (pp. 265-286).Mahwah, NJ: Lawrence Erlbaum Associates.

Gilbert, D. T. (1991). How mental systems believe. American Psychologist ,

46 , 107-119.

Gudjonsson, G. H. (2003). The psychology of interrogations and confessions .

Chichester, England: Wiley & Sons.

Inbau, F. E., Reid, J. E., Buckley, J. P., & Jayne, B. C. (2001). Criminal

interrogation and confessions, 4th edition . Gaithersburg, Maryland: Aspen Publishers.

Kassin, S. M. (2005). On the psychology of confessions: Does innocence put

innocents at risk? American Psychologist , 60, 215-228.

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Kassin, S. M., & Norwick, R. J. (2004). Why people waive their Miranda

rights: The power of innocence. Law and Human Behavior , 28, 211-221.

Mann, S., Vrij, A., & Bull, R. (2002). Suspects, lies and videotape: An

analysis of authentic high-stakes liars. Law and Human Behavior , 26 , 365-376.

Mann, S. & Vrij, A. (2006). Police officers' judgements of veracity, tenseness,

cognitive load and attempted behavioural control in real life police interviews.

Psychology, Crime, & Law , 12, 307-319.

Masip. J., Sporer, S., Garrido, E., & Herrero, C. (2005). The detection of

deception with the reality monitoring approach: A review of the empirical evidence.

Psychology, Crime, & Law , 11 , 99-122.

Moston, S., & Engelberg, T. (1993). Police questioning techniques in tape

recorded interviews with criminal suspects. Policing and Society , 3, 223-237.

National Research Council (2003). The polygraph and lie detection .

Committee to Review the Scientific Evidence on the Polygraph (2003). Washington,

DC: The National Academic Press.Spence, S. A., Hunter, M. D., Farrow, T. F. D., Green, R. D., Leung, D. H.,

Hughes, C. J., & Ganesan, V. (2004). A cognitive neurobiological account of

deception: Evidence from functional neuroimaging. Philosophical Transactions of the

Royal Society of London, 359 , 1755-1762.

Vrij, A. (1995). Behavioral correlates of deception in a simulated police

interview. Journal of Psychology , 129 , 15-28.

Vrij, A. (2000). Detecting lies and deceit: The psychology of lying and its

implications for professional practice . Chichester: John Wiley and Sons.

Vrij, A. (2004). Invited article: Why professionals fail to catch liars and how they

can improve. Legal and Criminological Psychology , 9, 159-181.

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Vrij, A. (2005). Criteria-Based Content Analysis: A qualitative review of the

first 37 studies. Psychology, Public Policy, and Law , 11 , 3-41.

Vrij, A. (2006). Challenging interviewees during interviews: The potential

effects on lie detection. Psychology, Crime, & Law , 12, 193-206.

Vrij, A., Akehurst, L., & Knight, S. (2006). Police officers', social workers',

teachers' and the general public's beliefs about deception in children, adolescents and

adults. Legal and Criminological Psychology, 11, 297-312.

Vrij, A., Mann, S., & Fisher, R. (2006a). An empirical test of the Behaviour

Analysis Interview. Law and Human Behavior, 30, 329-345.

Vrij, A., Mann, S., & Fisher, R. (2006b). Information-Gathering vs Accusatory

Interview Style: Individual Differences in Respondents' Experiences. Personality and

Individual Differences , 41, 589-599.

Vrij, A., Mann, S., Kristen, S., & Fisher, R. (in press). Cues to deception and

ability to detect lies as a function of police interview styles. Law and Human Behavior .

Vrij, A., Fisher, R., Mann, S., & Leal, S. (2006). Detecting deception bymanipulating cognitive load. Trends in Cognitive Sciences , 10, 141-142.

Vrij, A., Semin, G. R., & Bull, R. (1996). Insight into behaviour during

deception. Human Communication Research , 22, 544-562.

Walczyk, J. J., Schwartz, J. P., Clifton, R., Adams, B., Wei, M., & Zha, P.

(2005). Lying person-to-person about live events: A cognitive framework for lie

detection. Personnel Psychology , 58, 141-170.

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