Coaching and Deception
Let Me Inform You How to Tell a Convincing Story:
CBCA and Reality Monitoring Scores as a Function of Age, Coaching and Deception
Aldert Vrij12
Lucy Akehurst
Stavroula Soukara
Ray Bull
Running head: Coaching and Deception
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Correspondence should be addressed to: Aldert Vrij, University of Portsmouth, Psychology Department,
King Henry Building, King Henry 1 Street, Portsmouth PO1 2DY, United Kingdom or via email:
aldert.vrij@port.ac.uk
This study was sponsored by a grant from the Economic and Social Research Council (R000222820)
Coaching and Deception
Abstract
The first aim of this experiment was to examine whether being informed about a
method of detecting deception called Criteria-Based Content Analysis (CBCA) would
increase participants' CBCA scores when deceptive so that they might then be classified as
truthful. The second aim was to investigate whether Reality Monitoring could be used as an
alternative tool for verbal lie detection. The third aim was to examine whether participants'
social skills (social anxiety, self monitoring and social adroitness) affected their CBCA
scores. Participants (aged 6-8, 11-12, 14-15, and undergraduates) participated in a "rubbing
the blackboard" event. In a subsequent interview they told the truth or lied about the event,
after they were or were not taught some CBCA criteria. Truth tellers obtained higher CBCA
scores than liars, and those who were informed about CBCA obtained higher scores than
those who were not, except for the 6-8-year-olds. CBCA scores were also significantly
correlated with social skills. Finally, Reality Monitoring was a useful alternative to CBCA
for distinguishing between liars and truth tellers.
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Coaching and Deception
Let Me Inform You How to Tell a Convincing Story:
CBCA and Reality Monitoring Scores as a Function of Age, Coaching and Deception
To date, Criteria-Based Content Analysis (CBCA) -a systematic assessment of the
credibility of written statements- is probably the most popular instrument to assess the
veracity of written statements (Vrij, 2000).
CBCA is a systematic assessment of the credibility of written statements. Steller and
Köhnken (1989) compiled a list of 19 criteria which had been used in such assessments.
CBCA is based on the hypothesis, originally stated by Undeutsch (1967), that a statement
derived from memory of an actual experience differs in content and quality from a statement
based on invention or fantasy. This is known as the Undeutsch Hypothesis (Steller, 1989).
The presence of each criterion strengthens the hypothesis that the account is based on
genuine personal experience. Köhnken (1989, 1996, 1999, 2002) presented theoretical
support for the Undeutsch hypothesis and proposed that both cognitive and motivational
factors influence CBCA scores.
With regard to cognitive factors, it is assumed that, compared to those who fabricate a
story, someone who actually experienced an event would be able to produce descriptions
about this event which include more CBCA criteria, as some criteria (unstructured
production, contextual embedding, reproduction of speech, unusual details, etc.) are believed
to be very difficult for people to fabricate.
Other criteria are more likely to occur in truthful statements for motivational reasons.
Truthful persons will not be as much concerned with impression management as will
deceivers. Compared to truth tellers, deceivers would be more keen to try to construct a
report which they believe will make a credible impression on others, and will leave out
information which, in their view, will damage their image of being a truthful person
(Köhnken, 1999). As a result, a truthful person's statement is more likely to contain
information that is inconsistent with the beliefs/stereotypes that people have concerning truth
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Coaching and Deception
telling. The CBCA list includes several so-called "contrary-to stereotype" criteria (term
adapted from Ruby & Brigham (1998)): "spontaneous corrections", "admitting lack of
memory", "raising doubts about one's own testimony", etc..
CBCA was developed to evaluate statements from children. Many authors still
describe CBCA as a technique solely developed to evaluate statements made by children in
sexual offense trials (Honts, 1994; Horowitz, Lamb, Esplin, Boychuk, Krispin, & ReiterLavery, 1997). Others, however, advocate the additional use of the technique to evaluate the
testimonies of adults (Köhnken, Schimossek, Aschermann, & Höfer, 1995; Porter & Yuille,
1996; Ruby & Brigham, 1997; Steller & Köhnken, 1989). These authors have pointed out
that the underlying Undeutsch hypothesis is not restricted to children. The latter point of view
has received some empirical support to date. Significantly higher CBCA scores for truth
tellers than for liars have not only been found in studies with children witnesses (for example,
Akehurst, Köhnken, & Höfer, 2001; Lamb, Sternberg, Esplin, Hershkowitz, Orbach, &
Hovav, 1997a, b; Lamers-Winkelman & Buffing, 1996; Tye, Amato, Honts, Kevitt, & Peters,
1999; Vrij, Akehurst, Soukara, & Bull, 2002; Winkel & Vrij, 1995) but also in studies with
adult witnesses (for example, Akehurst et al., 2001; Höfer, Akehurst, & Metzger, 1996;
Köhnken et al., 1995; Landry & Brigham, 1992; Porter & Yuille, 1996; Ruby & Brigham,
1998; Sporer, 1997; Vrij, Edward, & Bull, 2001a, b; Vrij et al., 2002; Zaparniuk, Yuille, &
Taylor, 1995).
In the present study it was predicted that CBCA scores would be significantly higher
for truth tellers than for liars in both adult statements and child statements (Hypothesis 1). It
was further predicted that there would be a linear relationship between age and CBCA scores:
the older the participants, the higher their CBCA score (Hypothesis 2). Theoretically,
Hypothesis 2 could be explained in several ways. Cognitive abilities and command of
language develop throughout childhood, making it gradually easier to provide detailed and
rich accounts of what has been witnessed (Davies, 1991, 1994). Also, children are probably
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Coaching and Deception
less aware and/or less concerned with impression management than adults (Flavell, Botkin,
Fry, Wright, & Jarvis, 1968; Vrij, 2002). Positive correlations between CBCA scores and age
have been found in numerous studies before (see Vrij, in press, for an overview of these
studies).
In principle, it is possible that if people were to learn which methods CBCA
evaluators use to assess the credibility of their statements, they could try to "improve" their
statements in order to obtain high CBCA scores which could then be assessed as truthful by
CBCA judges. Previous experiments addressing this "coaching" issue have revealed that
lying participants who were informed about CBCA were indeed capable of producing
significantly higher CBCA scores than lying participants who were not informed (Vrij et al.,
2002; Vrij, Kneller, & Mann, 2000). The present experiment also addressed the question of
whether it is possible for people who have insight into the CBCA method to improve their
CBCA score. The main difference between the previous experiments and this experiment was
the age of the participants. Unlike the other experiments, we included a group of young
participants (6-8-year-olds). We expected participants to benefit from the coaching and
predicted that CBCA-coached participants would obtain higher CBCA scores than uncoached
participants (Hypothesis 3).
Recently, Reality Monitoring has been used as an alternative method to examine
verbal differences between responses believed to be true and false (Alonso-Quecuty, 1992,
1996; Alonso-Quecuty, Hernandez-Fernaud, & Campos, 1997; Höfer et al., 1996; Manzanero
& Diges, 1996; Roberts, Lamb, Zale, & Randall, 1998; Sporer, 1997; Vrij, Akehurst,
Soukara, & Bull, in press; Vrij, Edwards, Roberts, & Bull, 2000; Vrij et al., 2001a, b). The
core of Reality Monitoring is the claim that memories of experienced events differ in quality
from memories of imagined (e.g., fabricated) events. Memories of real experiences are
obtained through perceptual processes and are therefore likely to contain, amongst others,
perceptual information: details of smell, taste or touch, visual details and auditory details
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Coaching and Deception
(details of sound) and contextual information: spatial details (details about where the event
took place, and details about how objects and people were situated in relation to each other,
e.g., "He stood behind me") and temporal details (details about time order of the events, e.g.,
"First he switched on the video-recorder and then the TV", and details about duration of
events). Accounts of imagined events are derived from an internal source and are therefore
likely to contain cognitive operations, such as thoughts and reasonings ("I must have had my
coat on, as it was very cold that night") (Johnson, Hashtroudi, & Lindsay, 1993; Johnson &
Raye, 1981, 1998). One might argue that "experienced events" reflect truth telling whereas
"imagined events" reflect deception. Therefore, differences between truth tellers and liars
could be expected regarding Reality Monitoring criteria.
One of the benefits of the Reality Monitoring method, compared to CBCA, is that the
method is relatively straightforward to use and less time consuming to apply (Sporer, 1997;
Vrij et al., 2000, in press). Another benefit is that, unlike CBCA which consists of criteria
solely related to truth telling, Reality Monitoring contains both truth telling criteria and a
criterion indicative of deception (cognitive operations). However, Reality Monitoring needs
to be more thoroughly tested. For example, previous studies often have failed to find the
expected difference between liars and truth tellers regarding cognitive operations (AlonsoQuecuty, 1992, 1996; Höfer et al., 1996; Sporer, 1997; Vrij et al., 2000, 2001b). This might
have been caused by the nature of the event. For example, in Vrij et al.'s (2000, 2001b)
studies, participants were requested to give truthful or deceptive factual accounts of aspects
of a film they had seen. This allows little room for cognitive operations. Truth tellers were
asked to recall and liars were asked to fabricate what people in the film were doing, not what
they, themselves, were thinking. Cognitive operations, however, are related to people's own
thinking rather than recall of factual information about others. Therefore, the expected
difference in cognitive operations between liars and truth tellers might occur when people are
asked to describe their own activities during a certain period of time as this provides more
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Coaching and Deception
opportunity to include reports of cognitive operations. In support of this reasoning, Vrij et al.
(in press) found that liars did include more cognitive operations in their accounts than truth
tellers when they were asked to describe an event in which they were personally involved. In
order to further strengthen the support for the cognitive operations hypothesis we sought to
replicate this finding in the present study. It was hypothesised that truth tellers are likely to
include more perceptual and contextual information in their statements than liars, and that
liars are likely to include more cognitive operations in their statements than truth tellers
(Hypothesis 4). For the same reason that we expected age differences in CBCA scores (i.e.,
cognitive abilities and command of language develop throughout childhood which makes it
gradually easier to provide detailed accounts), we expected age differences in Reality
Monitoring scores as well: The older the participants, the higher their Reality Monitoring
score (Hypothesis 5).
Vrij et al. (2002) examined individual differences in CBCA scores. They
argued that some people are more eloquent and verbally skilled than others, and that these
differences may be related to social skills. They focused on three different social skills: social
anxiety, social adroitness and self monitoring. People who are socially anxious feel
discomfort in the presence of others (Buss, 1980) and their reports might therefore contain
less quality (contain fewer CBCA criteria) than participants who feel more comfortable in
social interactions. On the other hand, people who are socially adroit (Jackson, 1978) are
experienced in verbally manipulating other people. As a result, their statements might contain
more CBCA criteria than the statements of those who are less manipulative. Finally, people
differ in the extent to which they naturally engage in impression management. Those who are
high in self-monitoring (Snyder, 1987) are particularly concerned with making a favourable
impression on others, and have the tendency to adjust their nonverbal and verbal behavior in
order to create the desired effect on others. Therefore, it might be that high self monitors
naturally produce higher CBCA scores. Vrij et al.'s (2002) findings supported these
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Coaching and Deception
assumptions. Their findings have potential implications. Statement Validity Assessment
(SVA) experts typically look at alternative hypotheses to explain CBCA scores, such as
cognitive limitations of the child, characteristics of the interview, and motivational factors.
All these aspects are addressed in the Validity Checklist (Raskin & Esplin, 1991). Social
skills of the interviewee, however, do not appear in the Validity Checklist and are therefore
typically neglected. Vrij et al.'s (2002) findings suggest that social skills need to be
incorporated in the Validity Checklist. However, the correlations found between CBCA
scores and social skills were, although significant, not high (around r = .20). We therefore felt
that a replication of these findings was desirable. Obviously, if the same findings were
obtained, the plea to include social skills of the interviewee in the Validity Checklist would
be strengthened. The relationship between social skills and Reality Monitoring scores have
not been investigated to date. However, similar to CBCA scores, Reality Monitoring scores
are probably related to eloquency, and we therefore expected the same relationships as for
CBCA scores. In all, we predicted that social anxiety would be negatively correlated with
CBCA scores and Reality Monitoring scores and that social adroitness and self monitoring
would be positively correlated with CBCA and Reality Monitoring scores (Hypothesis 6).
Method
Participants
A total of 180 participants took part in the study, 92 (51%) males and 88 (49%)
females. Their mean age was M=14.13 years, SD=5.56. There were four different age groups:
44 6 to 8-year-olds (13 (30%) males and 31 (70%) females, four were 6 years old, 30 were 7
years old, and 10 were 8 years old), 35 11 to 12-year-olds (21 (60%) males and 14 (40%)
females, 16 were 11 years old and 19 were 12 years old), 44 14 to 15-year-olds (23 (52%)
males and 21 (48%) females, 13 14-year-olds and 31 15-year-olds), and 57 undergraduate
students (35 (61%) males and 22 (39%) females, their mean age was M=20.70 years, SD =
3.40).
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Coaching and Deception
Procedure
The experimental procedure was identical to Vrij et al.'s (2002, in press) procedures.
The experiment took place at a Students' Union (for undergraduates) and at local schools (for
children). Undergraduates were recruited under the guise of participating in an experiment
about "telling a convincing story" with the possibility of earning £5. Children were asked by
their teacher to go to see "a woman to play a game". (Prior to the study, parental informed
consent was obtained). Participants took part individually. First, the undergraduates signed an
informed consent form and filled out a questionnaire "about their personality" (which
included self reports concerning social anxiety, social adroitness and self monitoring, see
below). The 11-, 12-, 14- and 15-year-olds also filled out this questionnaire prior to the study.
For the 6-8-year-olds, the questionnaire was sent to their parents (after the children had
participated) who were asked to fill out the questionnaire on behalf of their children. After
entering the experimental room, the female experimenter made fairly brief, polite
conversation (exchanged names, what have you been doing?, etc.). From that moment events
differed for the participants depending on which of the conditions they were in. Allocation to
these conditions occurred at random.
Participants in the truthful condition (N = 86) played a game of "Connect 4" with the
experimenter (all 180 participants in this study knew how to play this popular game). During
the game, a person (we used different persons, see below) entered the room, said "Hello", and
"Excuse me for interrupting", and also said "Ah! You are playing Connect 4, I'm hopeless at
the game, I always lose!", walked to the blackboard and wiped some information
(complicated math formulas) off the blackboard, and then left the room. After the game, the
experimenter looked at the blackboard and then noticed that the information had been wiped
off. She then asked the participant whether he/she saw someone wiping off the information.
All participants in the truthful condition told the experimenter that the person who came in
during the game wiped the information off the blackboard. Then, the experimenter gave the
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Coaching and Deception
following instructions: "Actually, I know that the information should not have been wiped off
the blackboard, as it is needed for a lesson later on. In a minute you will be interviewed by
another woman. Her task is to find out who wiped the information off the blackboard. Now,
you know you did see who it was, so your task is to convince her that you did. All you need
to do is be truthful about everything that happened while you were in this room. So say that
we played a game of Connect 4 and that someone came in to wipe the blackboard. This is
very important as, if you are successful in convincing her that you are telling the truth, we
will give you (undergraduates - £5; 14-15-year-olds - £2; 11-12-year-olds - £2; 6-8-year-olds
- a present). At the end of the interview, she will tell you whether she believes you or not. If
she does believe that we played Connect 4 and that someone came in to wipe the blackboard,
we will give you the money/present when you come out. If she doesn't believe you, you will
not get any money/present at all. Do you understand?"1
Participants in the fabricating condition (N = 94) were told by the experimenter that
she (the experimenter) earlier wiped some important information off the blackboard which
was supposed to stay on there for a lesson later on. The participants were told that he/she
would be interviewed by another woman whose task was to find out who wiped the
information off the blackboard. The experimenter then asked the participants to pretend that
it wasn't the experimenter who wiped the information off the blackboard. Instead the
participants were asked to pretend that they (experimenter and participant) played Connect 4
and that someone else entered the room and wiped off the information during the game.
Identical to the truthful witness condition, it was stressed that if the participant was
successful in convincing the interviewer that it was someone else who wiped the information
off the blackboard, he/she would receive £5/£2/present, and that he/she would receive
nothing at all if the interviewer did not believe him/her. Again, participants were informed
that the interviewer would tell the participants at the end of the interview whether or not she
believed them.2
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Coaching and Deception
All participants were then randomly allocated to either the light coaching condition or
the heavy coaching condition. Participants in the light coaching condition (N = 91) were told
that it is important that the interviewer believes that the experimenter and participant played
Connect 4 and that someone came in who wiped the information off the blackboard. It was
further stressed that it is more likely that the interviewer would believe the participant if
he/she told in lots of detail, what happened when he/she was in the room. For example, just
saying: "Well, it was a bit boring really!" wouldn't convince the interviewer.
In addition to these light coaching instructions, participants in the heavy coaching
conditions (N = 89) were given further information. The information differed for liars and
truth tellers. Fabricating participants (except 6-8-year-olds) were given the following verbal
instructions: "Here are some more things to think about when you are in the interview. Our
research shows that these things help people to believe what you are saying: (a written
version of these verbal instructions was put in front of the participants as well)
(1) try to include as many details as you can. For example, include some details about your
"pretend" person. Was it a man or a lady? What was he/she wearing? (This is CBCA criterion
3).
(2) Describe "interactions", that is, describe how you think you would have reacted when we
were playing the game or when the person interrupted us. For example, "I think (name of the
experimenter) was a bit annoyed when I won the game" (CBCA criterion 5).
(3) Try to describe what people said to each other. For example, if someone had come into
the room, what do you think he/she would have said to us? What do you think we would have
said to one another when we were playing the game? (CBCA criterion 6).
(4) Pretend that something unusual or unexpected happened. For example, pretend that you
dropped some of your discs for the game on the floor. (CBCA criterion 7).
(5) Describe how you felt when you were in the room. For example, if someone had
interrupted our game, how do you think you would have felt? (CBCA criterion 12).
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Coaching and Deception
(6) Try to include how you think the person who wiped the blackboard was feeling."
Participants were then asked to think about the story they were going to tell in the
subsequent interview. When they said they were ready to be interviewed, they were asked to
practice the story with the experimenter first. The experimenter listened to the participants'
story and checked whether the participant included all six criteria. If not, questions about
these criteria were asked (i.e. "Could you think of something that the person who came in the
room might have said to us?"). The interviewee was then encouraged to include this piece of
information in their account as well. Finally, information about two more criteria (Criteria 14
and 15) were given:
(7) "The interviewer won't expect you to remember everything, because we can't always
remember everything. If you don't remember something, tell the interviewer that you can't
remember. Also, the interviewer will be more likely to believe you if you have forgotten
some of the little things she asks you about. So it will be a good idea to tell her you have
forgotten when she asks you. (CBCA criterion 15).
(8) Feel free to correct yourself if you think you have made a mistake, if you have
contradicted yourself or something." (CBCA criterion 14).
The coaching for 6-8-year-olds was slightly different. They were only taught criteria
3, 5 and 6, and the training was conducted in a more interactive manner (i.e. "Pretend a
woman came in: What was she wearing?" (child gives an answer); "What was the color of her
hair?" (child gives an answer), etc.. The child was then encouraged to include the answers
they had given in their upcoming interviews.
The heavy coaching condition for truthful participants was very similar to the heavy
coaching condition just discussed. Obviously, they were not asked to pretend something but
were simply asked to describe the actual event, i.e. were asked to describe what the person
who wiped the blackboard was wearing, were asked to mention exactly what was said while
the participant was in the room, etc..
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Coaching and Deception
After the coaching instructions were completed and after the participants had
practiced their stories with the experimenter, the participant was brought to the (female)
interviewer who was in another room. The interviewer was unaware of the condition the
participant was in, except from the witness/suspect status of the participants (see endnote 2).
(The interviewer needed to know the status of the participants as the instructions she had to
give to suspects and witnesses differed). After building rapport with the participant, the
interviewer gave participants in the witness condition the following instructions: "The reason
I am interviewing you is that I have heard that someone wiped some important information
off the blackboard in the room you were just in. I understand that you were in there just now
with (name of experimenter). I need to know if you saw anything that will help me to find out
who it was.3 Also, remember that my colleagues need to know whether I think you are telling
the truth or not. I would like you to tell me, in as much detail as possible, everything you can
remember about what happened when you were in that room just now. Give me as much
information as you can, even small details you do not think are very important".
After this free recall the interviewer told each participant that they had convinced her
(the interviewer) that they told the truth and that they would receive the money/present. (For
ethical reasons the interviewer was instructed to tell all children that she believed them,
regardless of how convincing their stories were). With regard to the undergraduates, she was
instructed not to give money to participants who gave very short statements. However, all
undergraduates did put effort in giving extensive and credible statements, and all were paid
£5. Outside, the participants received their money/present, were debriefed and thanked.
Questionnaire, CBCA Scoring, and Reality Monitoring scoring
Social anxiety was measured with Fenigstein, Scheier, and Buss' (1975) social anxiety
scale (5 items). The questions for the 6-8-year-olds (which were answered by their parents)
were written in a third person format. For example, the item "I get embarrassed very easily"
(which was used for the 11-12-year-olds, 14-15-year-olds, and undergraduates) was
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Coaching and Deception
rephrased to: "The child gets embarrassed very easily"). Answers could be given on answer
scales ranging from (1) untrue to (4) true (Cronbach's alphas were .86 (6-8-year-olds) and .77
(11-12-, 14-15-year-olds and undergraduates)). Social adroitness was measured with
Jackson's (1978) social adroitness scale (20 items). Again, the child questions were written in
a third person format (Cronbach's alphas were .77 (6-8-year-olds) and .76 (11-12-, 14-15year-olds and undergraduates)). Self-monitoring was measured with Briggs, Cheeck, and
Buss' (1980) self monitoring scale (21 items). Again, the child questions were written in a
third person format (Cronbach's alphas were .70 (5-6-year-olds) and .63 (11-12-, 14-15-yearolds and undergraduates)). Pearson correlations revealed that self monitoring and social
adroitness (r(177) = .41, p < .01) and self monitoring and social anxiety (r(177) = -.45, p <
01) were significantly correlated, whereas social adroitness and social anxiety (r(177) = -.12,
ns) were not.
Two independent raters received training in CBCA scoring. First, both raters read
several major published papers about CBCA (Raskin & Esplin, 1991; Steller, 1989; Steller &
Köhnken, 1989; Vrij, 2000; Vrij & Akehurst, 1998). Second, they were trained in CBCA
scoring by a British CBCA expert. The expert explained each criterion under investigation in
this study (see below) and gave examples of each criterion. Third, both the trainee raters and
the expert rater evaluated one example transcript individually (from a different study). The
three raters compared their results and feedback was given by the expert rater. Fourth, the
trainees received more transcripts and were asked to rate these transcripts at home. In a
follow up meeting, the results were evaluated and, again, feedback was given by the expert.
After that meeting the expert felt that at that time the two raters had obtained sufficient rating
skills and it was decided that the raters could commence their coding task for the present
experiment. Coding was carried out individually by the two trained coders only (they coded
the statements at home) and took place on the basis of the written transcripts of the
interviews. The raters were blind to the hypotheses under investigation, to the staged event,
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Coaching and Deception
and to the experimental conditions the participants were allocated to (although they were
aware that some transcripts would be truthful and some not). Some criteria ("accurately
reported details misunderstood" (criterion 10); "pardoning the perpetrator" (criterion 18) and
"details characteristic of the offense" (criterion 19)) were not scored, as they are specifically
related to (sexual) crimes. "Self deprecations" (criterion 17) was initially to be scored but was
never in fact present. This criterion was therefore disregarded, leaving a total of 15 CBCA
criteria to be assessed. The coders scored the strength of presence of criteria 1 and 2 in each
statement on 5-point Likert scales ((1) = absent, (5) is strongly present), and scored the
frequency of occurrence of the other criteria in each statement. We then calculated a total
CBCA score. This has been done before not only in experimental laboratory research (Tye et
al., 1999; Vrij et al., 2000, 2001a, b, 2002, in press; Winkel & Vrij, 1995) but also in real life
situations (Craig, Scheibe, Raskin, Kircher, & Dodd, 1999; Hershkowitz, Lamb, Sternberg, &
Esplin, 1997; Lamb et al., 1997a, b; Parker & Brown, 2000). In order to create the CBCA
scale the criteria were dichotomized. Dichotomizations for criteria 4 to 16 were based on the
absence or presence of each of the criteria in the interview. A score of 0 was assigned when
the criterion was absent, and a score of 1 when the criterion was present. For criteria 1 and 2,
a 0 was assigned when the criterion obtained a "1" rating on the 5-point Likert scale, and a 1
was assigned when the criterion obtained a score of 2, 3, 4, or 5 on the 5-point Likert scale.
For dichotomization of criterion 3, median splits were used.4 Total CBCA scores were
calculated for both coders. The correlation between these two CBCA scores was moderate
but acceptable (.66). In the present analyses we used as total CBCA score the average score
of the two coders. The score could range from 0 to 15.5
Two other raters received training in Reality Monitoring (RM) scoring. A British RM
expert (different from the CBCA expert) provided the raters with a detailed description of
how the criteria should be scored, including some case examples. Then, both the trainee
raters and the expert evaluated some example transcripts individually (from a different
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Coaching and Deception
study). The three raters compared their results and feedback was given by the expert. At this
stage the expert and the two raters felt that the raters were capable of scoring the transcripts
without any further instructions. This is in agreement with Sporer (1997) who also found that
it is much easier to teach (and to learn) RM scoring than CBCA scoring. With regard to the
present study, coding was carried out individually by the two trained raters (they coded the
statements at home) and involved the written transcripts of the interviews. The raters were
blind to the hypotheses under investigation, to the staged event, and to the experimental
condition (although they were aware that some transcripts would be truthful and some not).
The two raters scored per interview the frequency of occurrence of visual details (e.g., "I
walked in to the room" contains three visual details), auditory details (e.g., "She said to sit
down" contains one sound detail), temporal details (e.g., "We started playing" is one
temporal detail), spatial details (e.g., "And then the pieces fell on to the floor" contains one
spatial detail) and cognitive operations (e.g., "Because she was quite clever, she won the
game" contains one cognitive operation; so do "I presume that the two people knew each
other" and "She was quite tall for a girl"). Following previous examples (Vrij et al., 2000,
2001b, in press) a total Reality Monitoring score was calculated. In order to create the Reality
Monitoring scale the visual, auditory, spatial and temporal variables were dichotomized (see
also Vrij et al., 2000, 2001b, in press). Dichotomizations for auditory, temporal and spatial
details were based on the absence or presence of each of the criteria in the interview. A score
of 0 was assigned when the criterion was absent, and a score of 1 when the criterion was
present. Cognitive operations were dichotomized as well, with a score of '1' given if no
cognitive operations were present and a score of '0' when cognitive operations were present.
For dichotomization of visual details, median splits were used. For reasons explained in the
CBCA scoring paragraph (see above), different median splits were used for 6-8-year-olds and
the other participants. Total Reality Monitoring scores were calculated for both coders. The
correlation between these two Reality Monitoring scores was satisfactory (.71). In the present
15
Coaching and Deception
analyses we used as total Reality Monitoring score the average score of the two coders.6 The
Reality Monitoring scale contained five criteria (visual details, auditory details, spatial
details, temporal details and cognitive operations) and the total-score could range from 0 to
5.7
Results
CBCA Scores and Reality Monitoring Scores as a Function of Truth-status, Age, and
Coaching
In order to test Hypotheses 1 to 5, a MANOVA was conducted with Truth-status
(truth vs lie), Age (6-8, 11-12, 14-15, undergraduates) and Coaching (light vs heavy) as
factors and CBCA score, and Reality Monitoring score as dependent variables. At a
multivariate level, the analysis revealed main effects for all three factors, Truth-status, F(2,
163) = 23.62, p < .01, Age, F(6, 324) = 8.84, p < .01, and Coaching, F(2, 163) = 6.26, p <
.01. None of the interaction effects were significant.8
At a univariate level, the Truth-status factor revealed significant findings for both
dependent variables. In support of Hypotheses 1 and 4, truth-tellers obtained higher CBCA
scores (M = 6.73, SD = 1.5) than liars (M = 6.19, SD = 1.7), F(1, 164) = 6.24, p < .01, and
truth-tellers obtained higher Reality Monitoring scores (M = 3.77, SD = .8) than liars (M =
2.79, SD = 1.0), F(1, 164) = 47.49, p < .01.
Regarding the Age factor, univariate tests revealed significant findings for CBCA
scores, F(3, 164) = 17.18, p < .01. The linear trend, predicted in Hypothesis 2, emerged (see
Table 1). The older the participants, the higher their CBCA scores. The CBCA scores for 1415-year-olds and undergraduates were significantly higher than the CBCA scores for 6-8year-olds; 11-12-year-olds obtained significantly lower CBCA scores than undergraduates.
The CBCA scores for 6-8- and 11-12-year-olds did not differ significantly from each other,
neither did the CBCA scores for 14-15-year-olds and undergraduates. Univariate tests
revealed a significant effect for Reality Monitoring score as well, F(3, 164) = 3.35, p < .05.
16
Coaching and Deception
However, Tukey HSD tests did not reveal differences between the four age groups. One
could argue that this is caused by the inclusion of cognitive operations in the Reality
Monitoring score, as there is no reason to assume that younger children would include more
cognitive operations in their statements than older children or undergraduates (this is
necessary to obtain a higher Reality Monitoring score). We therefore excluded cognitive
operations from the total Reality Monitoring score for this analysis (the new total Reality
Monitoring score consisted of four dependent variables: visual, auditory, spatial and temporal
details). We conducted Tukey HSD tests on this newly constructed Reality Monitoring score
and the findings are shown in Table 1. The pattern which emerged is very similar to the
CBCA pattern just described, and supports Hypothesis 5.
Regarding the Coaching factor, univariate tests revealed one significant effect. As
was predicted in Hypothesis 3, heavily coached participants obtained higher CBCA scores
(M = 6.79, SD = 1.7) than lightly coached participants (M = 6.12, SD = 1.5), F(1, 164) =
10.89, p < .01.
Of theoretical interest are the Truth-status X Coaching and Coaching X Age
interaction effects. Although the Truth-status X Coaching effect regarding CBCA scores was
not significant, F(1, 164) = .82, ns, an interesting pattern emerged. The difference between
truth tellers and liars was not significant for the heavily coached participants, F(1, 87) = .82,
ns, but was significant for the lightly coached participants, F(1, 89) = 5.41, p < .05. In the
lightly coached condition truth tellers obtained a higher CBCA score (M = 6.50, SD = 1.4)
than liars (M = 5.80, SD = 1.4).
The Truth-status X Coaching interaction effect was significant for Reality Monitoring
scores, F(1, 164) = 5.02, p < .05. In the heavily coached condition, truth tellers obtained a
higher Reality Monitoring score (M = 3.60, SD = .9) than liars (M = 2.95, SD = .9, F(1, 87) =
11.38, p < .02. The same pattern emerged in the lightly coached condition, F(1, 89) = 46.86,
p < .01, with truth tellers obtaining higher Reality Monitoring scores (M = 3.95, SD = .7)
17
Coaching and Deception
than liars (M = 2.65, SD = 1.0). The differences between liars and truth tellers were larger in
the lightly coached than in the heavily coached condition.
Although the Coaching X Age interaction effect regarding CBCA scores and Reality
Monitoring scores was not significant, F(3, 164) = 1.35, ns and F(3, 164) = .31, ns
respectively, examining the results per age group is relevant, particularly for the CBCA
scores. The results are presented in Table 2. The results for the 6-8-year-olds showed that
coaching was not successful. CBCA scores for heavily coached and lightly coached
participants were almost identical and did not differ significantly from each other. For the
three remaining groups, however, the CBCA scores were significantly higher for heavily
coached participants than for lightly coached participants.
CBCA Scores, Reality Monitoring Scores and Social Skills
In order to test Hypothesis 6, Pearson correlations were carried out between CBCA
scores and Reality Monitoring scores on the one hand and social anxiety, social adroitness,
and self monitoring on the other hand. The results are shown in Table 3.
As was predicted in Hypothesis 6, CBCA scores were positively correlated with
social adroitness and self monitoring scores and negatively correlated with social anxiety
scores. All three correlations were significant. Regarding Reality Monitoring scores one
significant finding emerged. Reality Monitoring scores were negatively correlated with social
anxiety. A distinction between liars and truth tellers (see Table 3) revealed that the
correlation patterns, just described, particularly occurred when participants were lying.9
CBCA Scores and Reality Monitoring scores: Their Discriminative Power
In order to determine the usefulness of the detection techniques in classifying truth
tellers and liars, stepwise discriminant analyses utilizing the Wilks' Lambda method were
conducted. With this technique the variables remaining in the final analysis are those which
contribute to maximizing the correct assignment of the cases to the objective truth status. In
the analyses, the objective truth status was the classifying variable and the CBCA score, and
18
Coaching and Deception
Reality Monitoring score were the dependent variables. In order to examine whether CBCA
classifications would benefit from a 'lie criterion', the original, non-dichotomized, cognitive
operations variable was introduced as a dependent variable as well. Because coaching had an
impact on the dependent variables, analyses were carried out for the lightly coached
participants only. The results are given in Table 4.
As can be seen in Table 4, 60% of the cases could be correctly classified on the basis
of the CBCA scores alone, whereas 74% could be correctly classified on the basis of the
Reality Monitoring alone. The analysis which included CBCA scores plus cognitive
operations revealed that 74% of the cases could be correctly classified on the basis of these
two variables (both cognitive operations, Wilks' Lambda = .83, and CBCA score, Wilks'
Lambda = .71, contributed to the discriminant function). Finally, the analysis in which CBCA
and Reality Monitoring scores were included showed that only Reality Monitoring
contributed significantly to the discriminant function.10
Discussion
The experiment revealed that truth tellers obtained higher CBCA scores and Reality
Monitoring scores than liars. There is now a substantive number of studies showing that
CBCA scores and Reality Monitoring scores do discriminate between liars and truth tellers
(see Vrij (2000) for reviews). The finding regarding cognitive operations (presented in
endnote 8) is more exceptional. We have now demonstrated for the second time that,
conforming to predictions, liars, compared to truth tellers, include more cognitive operations
in their account when they describe a life-event (rather than recalling a film they have seen).
The discriminant analyses revealed that liars and truth tellers were more accurately classified
on the basis of their Reality Monitoring scores than on the basis of their CBCA scores. These
findings support those who claim that Reality Monitoring could be used as an alternative tool
of verbal lie detection. As mentioned in the Introduction, one of the advantages of Reality
Monitoring is that the method also contains a lie criterion (cognitive operations). The CBCA
19
Coaching and Deception
technique (which only scores for truth) might become more balanced and might result in
higher accuracy when lie telling criteria (criteria which indicate deception) are included. The
present findings support this assumption. A discriminant analysis which included the CBCA
scores and cognitive operations as dependent variables resulted in a higher hit rate (74%)
than the discriminant analysis with CBCA scores alone (60%). Also Vrij et al. (in press)
found that accuracy improved when cognitive operations was included as an additional
variable alongside CBCA. The analyses further revealed that more accurate classifications of
liars and truth tellers were made if the cognitive operations variable was removed from the
total Reality Monitoring scale and was introduced as a separate variable alongside this new
Reality Monitoring scale which did not contain cognitive operations (see endnote 10). This is
likely due to the fact that the cognitive operations variable is conceptually different from the
other criteria: its presence does not indicate truth telling (as is the case with the other
criteria), but lying. Treating the two sets of variables as distinctive sets of variables could
therefore be recommended.
A second aim of the experiment was to examine whether participants could improve
their CBCA scores when they were given insight into the CBCA criteria. The findings
revealed that coaching indeed improved participants' CBCA scores, however, not for the
youngest group of participants (6-8-year-olds). This will please those who support the use of
CBCA assessments regarding young children being used as evidence in criminal court.
However, our findings do not suggest that teaching young children to improve their CBCA
scores is impossible. The "training" was short (it lasted less then ten minutes) and perhaps
young participants would benefit from a more extensive training session. However, we do
believe that our findings suggest that training young children to improve their CBCA scores
is difficult.
Our final aim was to investigate to what extent CBCA scores are influenced by
participants' social skills. The same findings emerged as in our previous study (Vrij et al.,
20
Coaching and Deception
2002). CBCA scores were positively correlated with social adroitness and self monitoring
and negatively correlated with social anxiety. These findings also emerged when we
controlled for the effects of the coaching manipulation and age of the participants. On the
basis of these two studies, we therefore recommend SVA evaluators to take people's social
skills into account when they evaluate CBCA scores. This relationship between social skills
and CBCA scores was clearer in lying participants than in those who were telling the truth.
The same pattern emerged in Vrij et al.'s (2002) study. Perhaps this has to do with the
difficulty of the task. It seems plausible to suggest that the task was more difficult for liars
than for truth tellers. Perhaps a task needs to be verbally challenging in order for these social
skills focusing on verbal skills to discriminate.
The inter-rater agreements between the two coders regarding the individual CBCA
criteria were (i) sometimes low and (ii) mostly lower than their inter-rater agreement
regarding the total CBCA scale. These patterns are consistent with findings in previous
CBCA research (see Vrij, in press, for a discussion about these issues). It implies that, at least
on reliability grounds, experts involved in real-life cases should use the total CBCA scale
rather than relying on individual CBCA criteria. Although we are not aware of CBCA experts
who merely focus on individual criteria in real life cases, we cannot rule out that experts who
do not officially use the CBCA method but who are familiar with its content would do so.
Finally, five issues merit attention. First, different age groups received different
rewards, therefore effects of age were confounded with type of motivation. We varied the
reward so as to avoid such a confound. We believe that giving all participants the same
reward would have created a confound because the same reward (for example £5) would be
perceived as substantially higher by young children than by undergraduates. However, it is
difficult to determine what would be comparable rewards for different age groups. With
hindsight, we could have asked participants this. Second, the coaching manipulation for the
6-8-year-olds differed somewhat from the coaching manipulation of the other groups of
21
Coaching and Deception
participants. Although this created a confound in experimental terms, we had no other choice.
In a previous study (Vrij et al., 2002), we exposed young children to the heavy coaching
condition we used for older participants in this study but had to cancel this condition as some
children clearly did not understand the instructions. Third, we did not include a non-coaching
condition in our experimental design. We did so for ecological validity reasons. In
experimental studies participants are probably less motivated to make a convincing
impression than in real life situations. We were therefore afraid that not providing any
guidance to our participants might have resulted in poor quality statements. Obviously,
comparing a heavy coaching condition with a no coaching condition would have made
significant findings more likely, but even in the present study, where we compared heavy
coaching with light coaching, we found the predicted coaching effects on CBCA scores.
Fourth, following our previous study (Vrij et al., 2000), the parents rather than the children
themselves completed the social skills questionnaires in the 6-8-year-old age group. Asking
such young children to complete the questionnaires themselves was impossible for obvious
reasons. We have no reasons to believe that the results were affected by this possible
shortcoming. For example, the predicted relationships between social skills and CBCA scores
occurred even when the impact of 'age' was partialled out. Also, the parents were blind to the
hypotheses under investigation. Fifth, some sceptics will argue that the outcomes of this
study say little about SVA assessments in the field, as we only focused on CBCA and not on
the whole lengthy SVA procedure. They will say that CBCA should not be assessed
independent of the other components of the procedure. We disagree with those sceptics for
several reasons. First, although CBCA is only part of the SVA procedure it is the core part of
that procedure. Clearly, the outcome of SVA assessments should be received with high
scepticism if the core of the procedure (CBCA) is found not to discriminate between truth
tellers and fabricators. Second, a qualitative review of the application of statement analyses
in Swedish courts (one of the countries where SVA originated) showed that experts rely
22
Coaching and Deception
heavily on the CBCA outcomes (Gumpert & Lindblad, 2001). That is, although they
sometimes acknowledge that several external factors (typically those factors covered in the
Validity Checklist) might have affected a CBCA outcome, they never came to the conclusion
that these factors could solely explain the CBCA scores and therefore high-quality statements
(which result in high scores) were generally interpreted as referring to self-experienced
events.
23
Coaching and Deception
References
Akehurst, L., Köhnken, G., & Höfer, E. (2001). Content credibility of accounts
derived from live and video presentations. Legal and Criminological Psychology, 6, 65-83.
Alonso-Quecuty, M. L. (1992). Deception detection and Reality Monitoring: A new
answer to an old question? In F. Lösel, D. Bender, & T. Bliesener (Eds.), Psychology and
law: International perspectives (pp. 328-332). Berlin: Walter de Gruyter.
Alonso-Quecuty, M. L. (1996). Detecting fact from fallacy in child and adult witness
accounts. In G. Davies, S. Lloyd-Bostock, M. McMurran, & C. Wilson (Eds.), Psychology,
law, and criminal justice: International developments in research and practice (pp. 74-80).
Berlin: Walter de Gruyter.
Alonso-Quecuty, M. L., Hernandez-Fernaud, E., & Campos, L. (1997). Child witnesses:
Lying about something heard. In S. Redondo, V. Garrido, J. Perez, & R. Barbaret (Eds.),
Advances is psychology and law (pp. 129-135). Berlin: Walter de Gruyter.
Buss, A. H. (1980). Self-consciousness and social anxiety. San Francisco: Freeman.
Briggs, S. R., Cheek, J. M., Buss, A. H. (1980). An analysis of the Self-Monitoring
Scale. Journal of Personality and Social Psychology, 38, 679-686.
Craig, R. A., Scheibe, R., Raskin, D. C., Kircher, J. C., & Dodd, D. H. (1999).
Interviewer questions and content analysis of children's statements of sexual abuse. Applied
Developmental Science, 3, 77-85.
Davies, G. M. (1991). Research on children's testimony: Implications for interviewing
practice. In C. R. Hollin and K. Howells (Eds.), Clinical approaches to sex offenders and
their victims (pp. 93-115). Chichester, Great Britain: Wiley & Sons.
Davies, G. M. (1994). Children's testimony: Research findings and police
implications. Psychology, Crime, & Law, 1, 175-180.
Fenigstein, A., Scheier, M. F., & Buss, A. H. (1975). Public and private selfconsciousness: Assessment and theory. Journal of Consulting and Clinical Psychology, 43,
24
Coaching and Deception
522-527.
Flavell, J. H., Botkin, P. T., Fry, C. L., Wright, J. C., & Jarvis, P. T. (1968). The
development of role-taking and communication skills in children. New York: Wiley & Sons.
Gumpert, C. H., & Lindblad, F. (2001). Expert testimony on child sexual abuse: A
qualitative study of the Swedish approach to statement analysis. Expert Evidence, 7, 279-314.
Hershkowitz, I., Lamb, M. E., Sternberg, K. J., & Esplin, P. W. (1997). The relationships
among interviewer utterance type, CBCA scores and the richness of children's responses.
Legal and Criminological Psychology, 2, 169-176.
Höfer, E., & Akehurst, L., & Metzger, G. (1996, August). Reality monitoring: A chance for
further development of CBCA? Paper presented at the Annual meeting of the European
Association on Psychology and Law, Sienna, Italy.
Honts, C. R. (1994). Assessing children's credibility: Scientific and legal issues in
1994. North Dakota Law Review, 70, 879-903.
Horowitz, S. W., Lamb, M. E., Esplin, P. W., & Boychuk, T. D., Krispin, O., &
Reiter-Lavery, L. (1997). Reliability of criteria-based content analysis of child witness statements. Legal and Criminological Psychology, 2, 11-21.
Jackson, D. N. (1978). Interpreter's guide to the Jackson Personality Inventory. In P.
McReynolds (Ed.), Advances in psychological assessment, volume 4 (pp. 56-102). SanFrancisco: Jossey-Bass.
Johnson, M. K., Hashtroudi, S., & Lindsay, D. S. (1993). Source monitoring.
Psychological Bulletin, 114, 3-29.
Johnson, M. K., & Raye, C. L. (1981). Reality Monitoring. Psychological Review, 88, 67-85.
Johnson, M. K., & Raye, C. L. (1998). False memories and confabulation. Trends in
Cognitive Sciences, 2, 137-145.
Köhnken, G. (1989). Behavioral correlates of statement credibility: Theories,
paradigms and results. In H. Wegener, F. Lösel, & J. Haisch (Eds.), Criminal behavior and
25
Coaching and Deception
the justice system: psychological perspectives (pp. 271-289). New York, NJ: SpringerVerlag.
Köhnken, G. (1996). Social psychology and the law. In G. R. Semin, & K. Fiedler
(Eds.), Applied Social Psychology (pp. 257-282). London, Great Britain: Sage Publications.
Köhnken, G. (1999, July). Statement Validity Assessment. Paper presented at the preconference programme of applied courses 'Assessing credibility' organised by the European
Association of Psychology and Law. Dublin, Ireland.
Köhnken, G. (2002). A German perspective on children's testimony. In H. L.
Westcott, G. M. Davies, & R. H. C. Bull (Eds.), Children's testimony: A handbook of
psychological research and forensic practice (pp. 233-244). Chichester, United Kingdom:
Wiley.
Köhnken, G., Schimossek, E., Aschermann, E., & Höfer, E. (1995). The cognitive
interview and the assessment of the credibility of adult's statements. Journal of Applied
Psychology, 80, 671-684.
Lamb, M. E., Sternberg, K. J., Esplin, P. W. Hershkowitz, I., Orbach, Y., & Hovav,
M. (1997a). Criterion-based content analysis: A field validation study. Child Abuse and
Neglect, 21, 255-264.
Lamb, M. E., Sternberg, K. J., & Esplin, P. W. Hershkowitz, I., & Orbach, Y.
(1997b). Assessing the credibility of children's allegations of sexual abuse: A survey of
recent research. Learning and Individual Differences, 9, 175-194.
Lamers-Winkelman, F., & Buffing, F. (1996). Children's testimony in the
Netherlands: A study of Statement Validity Analysis. In B. L. Bottoms & G. S. Goodman
(1996), International perspectives on child abuse and children's testimony (pp. 45-62).
Thousand Oaks, CA: Sage Publications.
Landry, K., & Brigham, J. C. (1992). The effect of training in Criteria-Based Content
Analysis on the ability to detect deception in adults. Law and Human Behavior, 16, 663-675.
26
Coaching and Deception
Manzanero, A. L., & Diges, M. (1996). Effects of preparation on internal and external
memories. In G. Davies, S. Lloyd-Bostock, M. McMurran, & C. Wilson (Eds.), Psychology,
law, and criminal justice: International developments in research and practice (pp. 56-63).
Berlin, Germany: Walter de Gruyter.
Parker, A. D., & Brown, J. (2000). Detection of deception: Statement Validity
Analysis as a means of determining truthfulness or falsity of rape allegations. Legal and
Criminological Psychology, 5, 237-259.
Porter, S., & Yuille, J. C. (1996). The language of deceit: An investigation of the
verbal clues to deception in the interrogation context. Law and Human Behavior, 20, 443459.
Raskin, D. C., & P. W. Esplin (1991). Statement Validity Assessment: Interview
procedures and content analysis of children's statements of sexual abuse. Behavioral
Assessment, 13, 265-291.
Roberts, K. P., Lamb, M. E., Zale, J. L., & Randall, D. W. (1998, March). Qualitative
differences in children's accounts of confirmed and unconfirmed incidents of sexual abuse.
Paper presented at the biennial meeting of the American Psychology-Law Society, Redondo
Beach.
Ruby, C. L., & Brigham, J. C. (1997). The usefulness of the criteria-based content
analysis technique in distinguishing between truthful and fabricated allegations. Psychology,
Public Policy, and Law, 3, 705-737.
Ruby, C. L., & Brigham, J. C. (1998). Can Criteria-Based Content Analysis
distinguish between true and false statements of African-American speakers? Law and
Human Behavior, 22, 369-388.
Snyder, M. (1987). Public appearances/ private realities: The psychology of selfmonitoring. New York: Freeman.
Sporer, S. L. (1997). The less travelled road to truth: Verbal cues in deception detection in
27
Coaching and Deception
accounts of fabricated and self-experienced events. Applied Cognitive Psychology, 11, 373397.
Steller, M. (1989). Recent developments in statement analysis. In J. C. Yuille (1989).
Credibility assessment (pp. 135-154). Deventer, the Netherlands: Kluwer.
Steller, M., & Köhnken, G. (1989). Criteria-Based Content Analysis. In D. C. Raskin (Ed.),
Psychological methods in criminal investigation and evidence (pp. 217-245). New York:
Springer-Verlag.
Tye, M. C., Amato, S. L., Honts, C. R., Kevitt, M. K., & Peters, D. (1999). The
willingness of children to lie and the assessment of credibility in an ecologically relevant
laboratory setting. Applied Developmental Science, 3, 92-109.12
Undeutsch, U. (1967). Beurteilung der Glaubhaftigkeit von Aussagen. In U.
Undeutsch (Ed.), Handbuch der Psychologie Vol. 11: Forensische Psychologie (pp. 26-181).
Göttingen, Germany: Hogrefe.
Vrij, A. (2000). Detecting lies and deceit: The psychology of lying and the
implications for professional practice. Chichester, Great Britain: John Wiley & sons.
Vrij, A. (2002). Deception in children: A literature review and implications for
children's testimony. In H. Westcott, G. Davies, & R. Bull (Eds.), Children's testimony (pp.
175-195). Chichester, Great Britain: Wiley & Sons.
Vrij, A. (in press).Criteria-Based Content Analysis: A qualitative review of the first
37 studies. Psychology, Public Policy, and Law.
Vrij, A., & Akehurst, L. (1998). Verbal communication and credibility: Statement
Validity Assessment. In A. Memon, A. Vrij, & R. Bull, Psychology and law: Truthfulness,
accuracy and credibility (pp. 3-26). Maidenhead, Great Britain: McGraw-Hill.
Vrij, A., Akehurst, L., Soukara, S., & Bull, R. (2002). Will the truth come out? The
effect of deception, age, status, coaching, and social skills on CBCA scores. Law and Human
Behavior, 26, 261-283.
28
Coaching and Deception
Vrij, A., Akehurst, L., Soukara, S., & Bull, R. (in press). Detecting deceit via analyses
of verbal and nonverbal behaviour in children and adults. Human Communication Research.
Vrij, A., Edward, K., & Bull, R. (2001a). People's insight into their own behaviour
and speech content while lying. British Journal of Psychology, 92, 373-389.
Vrij, A., Edward, K., & Bull, R. (2001b). Stereotypical verbal and nonverbal
responses while deceiving others. Personality and Social Psychology Bulletin, 27, 899-909.
Vrij, A., Edward, K., Roberts, K. P., & Bull, R. (2000). Detecting deceit via analysis
of verbal and nonverbal behavior. Journal of Nonverbal Behavior, 24, 239-263.
Vrij, A., Kneller, W., & Mann, S. (2000). The effect of informing liars about CriteriaBased Content Analysis on their ability to deceive CBCA raters. Legal and Criminological
Psychology, 5, 57-70.
Winkel, F. W., & Vrij, A. (1995). Verklaringen van kinderen in interviews: Een
experimenteel onderzoek naar de diagnostische waarde van Criteria-Based Content Analysis
(CBCA). Tijdschrift voor Ontwikkelingspsychologie, 22, 61-74.
Zaparniuk, J., Yuille, J. C., & Taylor, S. (1995). Assessing the credibility of true and
false statements. International Journal of Law and Psychiatry, 18, 343-352.
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Table 1
CBCA scores and Reality Monitoring scores as a Function of Age (N = 180)
Age
6-8
11-12
m
14-15
sd
m
undergraduates
sd
m
sd
m
CBCA
6.23ab 1.6
RM3
2.22a 1.1
3
6.75bc 1.6
2.56a
sd
5.30a
7.25c 1.5
.9
3.05b
.7
3.09b
.9
The total Reality Monitoring score consisted of four variables: visual, auditory, temporal and spatial
details.
1.1
30
Coaching and Deception
Table 2
CBCA scores as a function of Coaching and Age
Coaching
CBCA scores
light
heavy
m
sd
m
sd
6-8
5.29
1.0
5.31
1.1 F(1, 42) = .00
11-12
5.63
1.3
6.94
1.7 F(1, 33) = 6.49*
14-15
6.36
1.4
7.13
1.7 F(1, 42) = 2.77*4
undergraduates
6.86
1.5
7.64
1.4 F(1, 55) = 3.87*
* p < .05
4
one-tailed test
31
Coaching and Deception
Table 3
Pearson Correlations between CBCA score, Reality Monitoring score, and Social Anxiety-, Social
Adroitness-, and Self Monitoring Scores
Total group (N = 177)
Social AnxietySocial Adroitness
CBCA
-.25**
RM
Self Monitoring
.23**
-.23**
.24**
-.03
.03
Liars (N = 92)
Social AnxietySocial Adroitness
CBCA
-.39**
RM
.29**
-.28**
Self Monitoring
.26*
.13
.09
Truth tellers (N = 85)
Social AnxietySocial Adroitness
CBCA
.215
-.02
RM
-.05
* p < .05
5
** p < .01
p = .056 (two-tailed)
Self Monitoring
.26*
-.11
.08
32
Coaching and Deception
Table 4.
Discriminant Analyses with Criteria-Based Content Analysis, Reality Monitoring and Cognitive Operations:
Lightly coached participants only (N = 91).
hit rates
Detection technique lie
truth
totalEigenvalue
Lambda
df
X2
CBCA
50%
60%
.06
.94
1
69%
5.41
RM
61%
88%
74%
.52
.65
1
37.43
CBCA + co
74%
74%
74%
.41
.71
2
30.09
CBCA + RM
61%
88%
74%
.52
.65
1
37.43
* p < .05, ** p <
.01
Coaching and Deception
1.
It might seem suspicious from the participant's perspective that the experimenter would know that an interview was about to
ensue in order to ascertain the truth of the blackboard mishap. We had prepared an answer which the experimenter would
give in case a participant asked a question about this. However, none of the participants in this study raised this issue. In
other words, we have no evidence that the participants were suspicious.
Telling the participants at the end of the interview whether or not the interviewer believed the participants reflects
police practice: such statements sometimes occur at the end of suspect and witness interviews.
2.
The truthful and deceptive conditions described are the witness conditions. Similar to Vrij et al. (2002) we also introduced
suspect conditions for the three oldest groups of participants. The truthful suspect condition was similar to the truthful
witness condition, but this time participants were accused of having wiped the information off the blackboard themselves. In
the deceptive suspect condition, participants had wiped off the blackboard themselves and were accused of having done so
in the subsequent interview. In addition to the promised gift if they succeeded in telling a convincing story, truthful and
deceptive suspects also faced a punishment if they were not convincing, they were be asked to write down in detail what has
happened. This suspect/witness manipulation did not yield a significant effect and is disregarded in this article. See Vrij et al.
(2002) for a theoretical rationale for this manipulation.
3.
The interviewer gave participants in the suspect condition the following instructions: "The reason I am interviewing you is
that I have heard that YOU wiped some important information off the blackboard in the room you were just in. I understand
that you were in there just now with (name of the experimenter). I need to know whether it was you or not!" For the
remaining part, the suspect interviews and instructions were identical to the witness interviews and instructions.
4.
Separate median splits were used for (i) 6-8-year-olds and (ii) for the remaining participants for the following reason: An
ANOVA with Age Group as factor and details as dependent variable (scores of 2 coders combined) revealed a significant
effect, F(3, 176) = 18.28, p < .01. Tukey HSD tests revealed that 6-8-year olds included significantly fewer details in their
statements (M = 14.75, SD = 5.8) than any of the other three groups (10-11-year-olds: M = 21.69, SD = 8.3; 14-15-yearolds: M = 24.80, SD = 8.2; undergraduates: M = 26.99, SD = 10.6). These three groups did not differ significantly from each
other. A median split for the whole group would therefore imply that almost all 6-8-year-olds would be allocated to the "low
score" group and many other participants to the "high score" group (as the median split would be relatively low).
5.
Inter-rater agreement were also calculated for the individual criteria on the original, non-dichotomized, scores. Several
(Pearson) correlations were high: reproduction of conversation (r = .83), quantity of details (r = .76), and admitting lack of
memory (r = .74); others were moderate: raising doubt about one's own testimony (r = .58), description of interactions (r =
.52), contextual embeddings (r = .51), accounts of own mental state (r = .45), superfluous details (r = .44), accounts of
other's mental state (r = .42); others were rather low but significant: unexpected complications (r = .35), spontaneous
corrections (r = .35), and logical structure (r = .34). The remaining correlations were not significant: unstructured production
(r = .20), related external associations (r = .11), and unusual details (r = .09). The latter two criteria were hardly present, and
appeared in less than 8% of the statements. Previously (Vrij et al., 2002), we left out the criteria with low reliability before
computing a total CBCA score. However, this does not reflect real-life practice where CBCA experts typically rely on all the
criteria they assess. We therefore included all 15 criteria in the total CBCA score, and the correlation between the total
CBCA scores of both judges (.66) justified this. We return to this issue in the Discussion.
6.
Inter-rater agreements were also calculated for the five individual criteria. All Pearson correlations were satisfactory:
auditory details (r = .96), temporal details (r = .87), visual details (r = .76), spatial details (r = .68) and cognitive operations (r
= .61).
7.
All truthful participants participated in more or less the same staged event. It might therefore be that the truths told by these
participants bore certain similarities. These similarities could be picked up by the CBCA and Reality Monitoring raters after
a few trials of coding, and this "knowledge" might have affected their codings. We do not think that this actually happened.
Coaching and Deception
34
Although there were similarities in the staged event, there were also differences which were purposefully introduced by us in
order to prevent this happening. For example, different people were used to come into the room and wipe the blackboard.
Also, the same person wore different clothes at different times. As a result, the descriptions of the "actor" differed
considerably even in the truthful condition. (Because variations of the same staged event were introduced, we videotaped all
participants while they were in the room with the experimenter, and checked the veracity of their stories afterwards by
comparing their statements with what actually had happened. We did not come across any commissions, purposefully
distorting the truth, in the truthful reports). Additionally, not all truthful participants gave a complete account, with some
participants describing some features and other participants describing totally different features.
8.
For reasons pointed out in the Introduction, we were also interested in the results for the cognitive operations variable
separately. An ANOVA was conducted with Truth-status, Age and Coaching as factors and cognitive operations (the
original, not dichotomized scores) as dependent variable. The analysis revealed main effects for Truth-status, F(1, 164) =
38.56, p < 01), and Age, F(3, 164) = 7.18, p < .01), and a Truth-Status X Age interaction effect, F(3, 164) = 3.88, p < .05.
The interaction revealed that liars included significantly more cognitive operations in their accounts than truth tellers in all
age groups except in the youngest age group (6-8-year-olds: M = .41, SD = .9 vs M = .10, SD = .3, F(1, 42) = 2.37, ns; 1112-year-olds: M = .56, SD = .5 vs M = .22, SD = .4, F(1, 33) = 4.99, p < .05; 14-15-year-olds: M = 1.17, SD = 1.1 vs M =
.40. SD = .6, F(1, 42) = 8.12, p < .01; undergraduates: M = 1.55, SD = 1.3 vs M = .24, SD = .4, F(1, 55) = 26.09, p < .01).
Tukey HSD tests regarding the Age main effect revealed that 6-8-year-olds included fewer cognitive operations in their
accounts (M = .26, SD = .7) than the other age groups which did not differ significantly from each other (11-12-year-olds: M
= .39, SD = .5; 14-15-year-olds: M = .82, SD = 1.0; undergraduates: M = .93, SD = 1.2).
9.
Partial correlations controlling for (i) the coaching manipulation and (ii) age of the participant revealed the same significant
effects as the effects presented in Table 3, suggesting that age and coaching have no moderated impact on the relationships
between social skills and CBCA and Reality Monitoring scores.
10.
In subsequent analyses, we separated cognitive operations from the Reality Monitoring scale (leaving the Reality Monitoring
scale with four variables: visual, auditory, temporal and spatial details) and included the new Reality Monitoring scale and
cognitive operations (original, non-dichotomized scale) as two separate dependent variables in the discriminant analysis.
This analysis yielded higher accuracy rates than the accuracy rates presented in Table 4 (lie: 76%, truth: 88%, total 81%) and
both Reality Monitoring scores (Wilks' Lambda = .82 and cognitive operations, Wilks' lambda = 56, contributed
significantly to the discriminant function). A discriminant analysis with total CBCA score, total (new) Reality Monitoring
score and cognitive operations as dependent variables gave high accuracy rates too (lie: 76%, truth: 93%, total: 84%). All
three variables contributed to the discriminant function (Reality Monitoring score, Wilks' Lambda = .82, cognitive
operations, Wilks' Lambda = .56, CBCA score, Wilks' Lambda = .55).
Analyses per age group are available from the first author.