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Lies, Lies and More Lies

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Lying is a deliberate attempt to transmit messages that mislead others. Here, we examined the frequency of use of the so-called filler word 'um' during lying versus truth-telling in low-stakes laboratory-elicited lies (Study 1) and also in high-stakes real-life lies (Study 2). Results from a within-subjects false opinion paradigm showed that instances of 'um' occur less frequently during lying compared to truth-telling. Converging evidence was provided upon examining the lies of a convicted murderer. These results contribute to our understanding of linguistic markers of deception behaviour. More generally, they assist in our understanding of the role of utterances such as 'um' in communication. Utterances such as 'um' may not be accurately conceptualised as filled pauses/hesitations or speech disfluencies/errors whose increased usage coincides with increased cognitive load or increased arousal. Rather, they may carry a lexical status similar to interjections and form an important part of authentic, natural communication -that is somewhat lacking during lying.
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Lies, Lies and More Lies
Joanne Arciuli (jarciuli@usyd.edu.au)
Faculty of Health Sciences, University of Sydney
Australia
Gina Villar (gina_villar@optusnet.com.au)
Department of Psychology, Charles Sturt University
Australia
David Mallard (dmallard@csu.edu.au)
Department of Psychology, Charles Sturt University
Australia
Abstract
Lying is a deliberate attempt to transmit messages that mislead
others. Here, we examined the frequency of use of the so-
called filler word ‘um’ during lying versus truth-telling in low-
stakes laboratory-elicited lies (Study 1) and also in high-stakes
real-life lies (Study 2). Results from a within-subjects false
opinion paradigm showed that instances of ‘um’ occur less
frequently during lying compared to truth-telling. Converging
evidence was provided upon examining the lies of a convicted
murderer. These results contribute to our understanding of
linguistic markers of deception behaviour. Mo re generally,
they assist in our understanding of the role of utterances such
as ‘um’ in communication. Utterances such as ‘um’ may not
be accurately conceptualised as filled pauses/hesitations or
speech disfluencies/errors whose increased usage coincides
with increased cognitive load or increased arousal. Rather,
they may carry a lexical status similar to interjections and
form an important part of authentic, natural communication -
that is somewhat lacking during lying.
Keywords: Deception, Lies.
Linguistic Cues to Deception
Lying has been variously described as threatening the moral
fabric of our society (Bok, 1978) and an important
developmental milestone (deVilliers & deVilliers, 1978)
that may be lacking in some developmental disorders (e.g.,
Autism Spectrum Disorders: Sodian & Frith, 1992).
Certainly, lying is a part of everyday social interactions –
with some studies suggesting that people lie on average
once or twice a day (DePaulo, Kashy, Kirkendol, Wyer, &
Epstein, 1996) and may be prosocial in certain situations
(Spence et al., 2004). Despite the frequency with which we
are exposed to lies, people’s ability to discriminate lies from
truth is equal to that of chance (Bond & DePaulo, 2006).
This inaccuracy appears to stem from a number of factors
including undue reliance on nonverbal cues such as body
movements (Mann, Vrij & Bull 2004). A recent study
showed that even trained school teachers, social workers
and police are poor deception detectors and they perform
poorly regardless of whether the liars are 5-6 years of age,
adolescents or adults (Vrij, Akehurst, Brown & Mann,
2006). Indeed, assessment of behavioural cues to deception
is fraught with difficulty as these cues may be “subtle,
dynamic and transitory [and therefore] often elude humans’
conscious awareness” (Meservy, Jensen, Kruse, Burgoon &
Nunamaker, 2005). The need for accurate deception
detection in view of the poor performance of human lie
detectors and other currently available methods (such as the
polygraph which is suggested by some to be more of a guilt
detector than a lie detector), has led to considerable research
attention being focused on improving detection methods
using formal, objective procedures. The current study
provides an analysis of a particular aspect of language usage
during lying vs. truth-telling – the prevalence of so-called
filler words such as ‘um’.
To date, researchers have investigated a wide range of
language behaviours in both spoken and written output
including measures of quantity, complexity, uncertainty,
nonimmediacy, expressivity, diversity, redundancy,
informality, specificity, causation and affect (e.g., see Bond
& Lee, 2005; DePaulo, Lindsay, Malone, Muhlenbruck,
Charlton & Cooper, 2003; Newman, Pennebaker, Berry &
Richards, 2003; Rassin & Van Der Heijden, 2005; Sporer &
Schwandt, 2006; Zhou, Burgoon, Nunamaker & Twitchell,
2004; Vrij, Edward, Roberts & Bull, 2000; Vrij & Mann,
2004). The results of studies that have examined multiple
linguistic cues are impressive and some studies have
demonstrated deception detection rates of 67% which is
significantly better than the chance levels obtained by
human lie detectors (e.g., Newman et al., 2003). A meta
analysis of 120 deception studies conducted by DePaulo et
al. (2003) found that, in general, liars provide fewer details,
make more negative statements, sound more uncertain,
impersonal, evasive and unclear, and produce more words
that distance themselves from their statements and the
person or people to whom they are lying when compared
with truth-tellers. An important challenge for researchers
working in this area is to focus on refining the definition
and assessment of particular linguistic cues and to provide a
more thorough explanation of why they are related to
deceptive behaviour.
It has been suggested that utterances such as ‘um’
constitute filled pauses/hesitations (e.g., Maclay & Osgood,
1959) or production errors that render speech disfluent in a
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similar way to repetitions, repairs and false starts (Chomsky,
1965; Clark & Wasow, 1998; Goldman-Eisler, 1968).
Recent research has challenged such notions by suggesting
that these utterances have lexical status like other English
words. Clark and Fox Tree (2002) claimed that utterances
such as ‘um’ have lexical status (a status that is perhaps
similar to the open-class of words termed interjections
which includes items such as alrighty’ and ‘woops’) and
that they have “conventional phonological shapes and
meanings and are governed by the rules of syntax and
prosody” (p. 3). Unrelated to research on deception, Clark
and Fox Tree’s analysis of 170,000 words from 50 face-to-
face conversations demonstrated that speakers exhibit use of
‘um’ when marking delays in speaking (for example, in an
attempt to keep the floor or cede the floor) and that they
plan for, formulate and produce such utterances just as they
would any other English word. A study of speech
recognition in Spanish demonstrated that incorporation of
such utterances as lexical items (rather than noise) in models
of automatic speech recognition improves the recogniser’s
performance (Rodriguez & Torres, 2006).
Researchers in the area of deception have tended to
theorise that ‘um’ may occur more often during lying than
truth-telling. It has been argued that this increased
prevalence may reflect a lack of language planning that
accompanies the increased cognitive load (e.g., related to
effortful monitoring of responses) and/or increased arousal
(e.g., related to heightened feelings of guilt, fear or
excitement) that often occurs during lying (e.g., Hosman &
Wright, 1987; Vrij & Winkel, 1991). In the current study,
we examined the possibility that ‘um’ may, in fact, appear
less often during lying compared to truth-telling. We
speculate that there are two reasons why this might be the
case. The first relies on an assumption that lying is, at least
to some degree, reflective of inauthentic and somewhat less
natural processes compared to truth-telling. If ‘um’ forms a
part of natural, effortless language use then we might expect
to see less of it when language is inauthentic (i.e., during
lying). In this sense, decreased use of ‘um’ during lying
compared to truth-telling may not be under the direct control
of the speaker. The second reason relies on the assumption
that people may monitor their language use very carefully
during lying and try to strategically remove or mask cues to
deception. Thus, liars may deliberately reduce their use of
‘um’ in line with an understanding of ‘um’ being a
hesitation or disfluency reflective of uncertainty (e.g.,
Akehurst, Köhnken, Vrij & Bull 1996; Vrij & Semin, 1996).
In this sense, decreased use of ‘um’ during lying may be
under the direct control of the speaker. In either case the
result is the same – we would expect to see decreased use of
‘um’ during lying. In a first for deception research, we
examined both low-stakes, laboratory-elicited lies (Study 1)
and high-stakes, real-life lies (Study 2) to determine the role
of ‘um’ as a useful linguistic marker.
Study 1: Low-stakes Laboratory-elicited Lies
We elicited language in the context of an interactive
‘interview’ setting (rather than a monologue) for two
reasons. First, we wanted to ensure a listener was present
because it has been suggested that items such as ‘um’ may
be used, consciously or otherwise, for the listener’s benefit
(as opposed to being reflective of the speaker’s speech-
planning processes). Second, the presence of a conversant
may assist in encouraging speakers to lie convincingly.
Method
Participants A total of 32 participants (22 females and 10
males) with an average age of 20.2 years (SD = 4.8) took
part in exchange for course credit.
Procedure We employed a false opinion paradigm based on
the procedure described by Frank and Ekman (2004) and
participants took part in individual sessions lasting
approximately 30 minutes. At the beginning of the session
each participant was given a social issues questionnaire (on
topics of general interest such as “Should smoking be
banned in all enclosed public places?”). We asked each
participant to provide their opinion on each topic (1 =
strongly disagree, 7 = strongly agree) and to rate how
strongly they personally felt about each issue (1 = no
feelings, 7 = very strong feelings). Based on these responses
we selected two topics for each participant for which
participants held both a strong opinion (of either agreement
or disagreement) and had strong feelings. Wherever
possible, we chose issues for which the participant had
reported an opinion rating of either one or seven and had
also provided a value of seven for personal feelings about
the issue. For one topic participants were asked to give a
truthful account of their views and for the other topic
participants were asked to provide an untruthful account of
their views (i.e., to lie). The two selected topics were
randomly assigned to be either the truthful or the untruthful
account. The experimenter then told the participant that they
would be asked to lie or tell the truth about their opinion on
some of the social issues that had been presented to them in
the social issues questionnaire during a video-taped
interview (a different experimenter conducted the
interviews).
Data Preparation Interviews were transcribed by a blinded
research assistant and checked by a second blinded research
assistant. An excerpt from an interview where the
participant was discussing the topic of same sex marriage is
as follows: …Um, well I think they’re just like any other
person so um they should just have the same chance as any
other Australian to get married um and it’s sort of up to
them whether or not they want to…”. Tagging was
undertaken by a sound engineer who was blind to the
experimental conditions. In the tagging of ‘um’ instances,
examples of ‘uh’ were not tagged as ‘um’ unless they were
characterised by vowel nasalization (anticipatory
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nasalization occurs when speakers intend to close with a
nasal consonant such as /m/).
Results
On average, participants produced 157.61 words when
telling the truth and 174.35 words when lying. A 2
(condition: lying vs. truth-telling) x 2 (sex: female vs. male)
ANOVA revealed no significant effects in terms of total
number of words produced during lying vs. truth-telling (all
Fs < 1). For each participant, we calculated the number of
instances of ‘um’ as a percentage of the total number of
words. Descriptive statistics regarding frequency of ‘um’ (as
a percentage of total output) are provided in Table 1.
Table 1: Means (and standard deviations)
Truth
Lies
Female
2.28
(1.42)
1.61
(1.34)
Male
2.44
(2.54)
1.51
(1.42)
The analysis of the percentage of ‘um’ utterances revealed a
significant main effect of deception (F(1,30) = 10.12, p =
.003) with significantly more instances in the truth-telling
condition. In contrast, there was no main effect of gender
and no interaction between gender and deception (both Fs <
1).
Study 2: High-stakes Real-life Lies
Four weeks following the disappearance of his pregnant
wife and prior to his subsequent arrest for her murder, key
suspect Scott Peterson gave a series of media interviews
prompting intense and often heated public speculation as to
whether or not he was telling the truth when he protested his
innocence. For several weeks prior to these interviews,
police recorded hours of telephone conversations between
Peterson and his mistress, Amber Frey – a person who
Peterson initially believed was unaware he was even
married, let alone the murderer of his wife and unborn child.
The media interviews and taped telephone conversations all
contained examples of lying and truthful speech. Here we
present an analysis of the telephone conversations.
Method
Participant Scott Lee Peterson, a North American
Caucasian male, was arrested in April, 2003, for the murder
of his wife, Laci Peterson, who disappeared on Christmas
Eve, 2002. Peterson was subsequently charged and
convicted under the California Penal Code of the double-
murder of his pregnant wife and their unborn son in 2004.
Peterson had no prior convictions. Peterson was sentenced
to death and, at the time of writing, is on death row in San
Quentin State Prison. He was born in San Diego, California,
on October 24, 1972 and English is his first language.
Peterson’s highest level of academic achievement is a
university degree in agricultural business and prior to his
arrest he was employed as a fertilizer salesman.
Case Details Scott Peterson reported his wife, Laci
Peterson, missing from their Modesto California home on
December 24, 2002. The 27 year old was due to deliver her
first child, to be named Conner, 6 weeks later. Peterson was
interviewed by the police on several occasions and he was
under police surveillance from early January 2003 - search
warrants had been issued on his home, vehicles and place of
business and he was clearly a person of interest in the case.
In the first police interview conducted on the day of
Laci’s disappearance, Peterson was asked if he was involved
with another woman, to which he answered no. However,
six days after Laci was reported missing, a Fresno woman
by the name of Amber Frey contacted police to say she had
been having a romantic relationship with Peterson for
several weeks since November 19, 2002. She claimed that
during that time Peterson had lied to her about his real
circumstances - that he was a widower, his wife had recently
died, he lived in Sacramento and he was flying to Paris for
business over Christmas – and she had only been told of his
real identity by a friend who recognised Peterson from news
reports, the day of Frey’s contact with police. Frey agreed to
co-operate with police by secretly taping her telephone
conversations with Peterson from December 31. He
continued to call her throughout the time of the search for
his pregnant wife during December and January, all the
while maintaining the charade of a jet-setting widower.
The same day Frey first came forward (December 30,
2002), police asked Peterson if he had been having a
relationship with another woman and once again he denied
it. A week later, police confronted him with a photograph of
Frey and once again he denied any involvement with her.
Shortly after that (January 6, 2003), Peterson told Frey he
had lied to her about his circumstances and confessed to her
about the search for his missing pregnant wife. At the
urging of police, Frey made a media statement on January
24, 2002 and so their affair became public knowledge. The
telephone calls between Frey and Peterson continued after
this time, and these too were taped by Modesto police. In
response to the public outcry about Peterson’s relationship
with Frey, Peterson agreed to conduct four televised media
interviews from January 27 – 29, 2002. Peterson was later
found to have lied on at least one occasion during these
interviews.
The bodies of Laci and Connor were discovered on the
shores of San Francisco Bay on March 12, 2003. On April
18, 2003, Scott Peterson was arrested by police for the
murders of his wife and unborn child and charged with
double homicide. The case went to trial in June, 2004, with
Peterson pleading not guilty of the charges. Transcripts of
the four media interviews referred to above, in addition to
audio presentations of the taped telephone conversations
between Frey and Peterson, formed part of the prosecution’s
case against Peterson and were admitted as evidence at trial.
Five months later the jury found him guilty of murder in the
2331
first degree for his wife and murder in the second degree for
his unborn son.
Data Analysis Transcriptions of The Frey Tapes and
corresponding audio recordings were admitted as evidence
at trial and were accessed through electronic material
available on the public record at http://pwc-
sii.com/CourtDocs/Pexhibits.htm. Prior to analysis of the
speech data, each of the transcripts was carefully compared
to the original audio to ensure they were a complete and
verbatim record of the interviews.
The next step was to identify the portions of telephone
conversation that could be verified as being truth or lie, a
methodology that is congruent with the design employed by
Vrij and Mann (2001), Mann, Vrij and Bull (2002) and
Davis, Markus, Walters, Vorus and Connors (2005). This
necessitated a strong familiarisation with the Trial Record
and case information available on the public record. It was
necessary to read through each of the transcripts line by line
and isolate any utterances that could be strongly supported,
by evidence presented at trial or from another reputable
source (such as a police media release), as either truthful or
deceptive. Deception may be defined as a deliberate attempt
to manufacture, hide or manipulate information, in order to
create a belief in others that the communicator knows to be
false (Masip, Garrido & Herrero, 2004). In keeping with this
definition, deceptive utterances were identified as those
samples of speech where information was manufactured,
hidden or manipulated. Fragments of speech that could not
be verified were discarded from further analysis (e.g., all of
Scott Peterson’s personal opinions were eliminated from the
data set).
An example of some speech from the deception
condition: “Okay if you can hear me I’ll be in Paris
tomorrow. I’m taking a flight from here in the country in
Normandy right now so I’ll call you tomorrow.” An
example of some speech from the truth condition: “Um well
I’ll just I’ll just tell you. Ah you haven’t been watching the
news obviously. Um I have not been traveling during the
last couple weeks. I have I have lied to you that I’ve been
traveling.”
Of the remaining data, the number of words in the Lie
and in the Truth conditions was counted as a measure of
sample size. Data were analysed using the log likelihood
ratio (LR) test (see Rayson & Garside, 2000). LR is less
likely to overestimate significance than traditional statistical
tests such as z-ratios that rely upon assumptions of a normal
distribution. Similarly, where rare words are observed in
frequency profiles, LR is less likely to overestimate the
significance of such an event. Of particular relevance here,
it has the added benefit of being suitable for comparison of
relatively small texts and texts of differing lengths
(Dunning, 1993; Rayson, Berridge & Francis, 2004). LR
refers to the logarithm of the ratio between the likelihood
that the truthful and deceptive speech inputs from the
participant have the same linguistic profile and the
likelihood that the linguistic profiles differ from each other.
The sign preceding the log likelihood ratio (LR) shows the
direction of the relationship, with ‘+’ indicating a higher
frequency in the truthful condition and -’ indicating a
higher frequency in the deceptive condition.
Results
There were 883 words in the deception condition and 1,077
words in the truth condition. The frequency of ‘um’ as a
percentage of the total number of words in that condition are
provided in Table 2.
Table 2: Linguistic behaviour as a function of veracity
Truth
Lies
LR
3.71
0.12
+40.09
LR was statistically significant p < .0001.
General Discussion
In a first for research on deception, we investigated the use
of ‘um’ in both low-stakes laboratory-elicited lies and high-
stakes real-life lies. The combination of these methods
provides powerful converging evidence. Results from Study
1 indicated that during low-stakes laboratory-elicited lies
instances of ‘um’ were significantly more frequent during
truth-telling – their usage appeared to be restricted during
lying. Results from Study 2 confirmed this pattern in high-
stakes real-life lies.
We put forward two possible explanations for these
findings. It may be that utterances such as ‘um’ are more
accurately conceptualised as conventional English words
rather than filled pauses/hesitations or speech
disfluencies/errors (see Clark & Fox Tree, 2002; Fox Tree,
2006). Indeed, research unrelated to deception behaviours
provides converging evidence for the special status of
utterances such as ‘um’ which have been found to have
different distribution patterns to other types of disfluencies
such as repetitions and false starts. Bortfeld et al. (2001)
found that these utterances “may be a resource for or a
consequence of interpersonal coordination” (p. 123). As
such, these utterances are an important part of authentic,
natural speech (that is presumably somewhat lacking during
lying). Accordingly, while the use of utterances such as
‘um’ may not be under strategic control we would expect
usage to be lessened during lying (compared to truth-
telling). The second possibility is that the use of utterances
such as ‘um’ is under direct control and that participants
reduce their usage during lying in an effort to mask
deception. In line with this view, speakers remove what they
see as markers of uncertainty (utterances such as ‘um’)
when they lie (e.g., Akehurst et al., 1996; Vrij & Semin,
1996).
The outcome of each of these scenarios is the same
fewer utterances such as ‘um’ during lying. Importantly,
while it seems possible that the number of instances of ‘um’
(i.e., frequency of use) may be under strategic control it
seems unlikely that other acoustic characteristics of these
2332
utterances, such as duration and amplitude, could be as
easily controlled in a straightforward way. However, this
remains an open empirical question to be investigated in
future studies.
A question that is often raised in research on linguistic
cues to deception is whether rehearsal affects lying. So-
called ‘fillers’ are thought to be used less often in rehearsed
speech. It might be speculated that Peterson was able to
rehearse his lies but is it the case that people’s familiarity
with arguments concerning current social issues resulted in
the use of ‘rehearsed speech’? Over time, people might
become increasingly aware of both sides of the argument
concerning particular social issues; however, we imagine
that if there is any significant rehearsal involved, this would
relate to one side of an argument more than the other (most
likely, the side that the participant believes in, their ‘truth’).
Thus, we might have expected to see fewer so called fillers
in the truthful condition during laboratory-elicited lies as
this condition is more likely to reflect speech that
participants have, personally, rehearsed a number of times.
Our results showed the opposite pattern of results (fewer
fillers during lying).
Of all the potential linguistic cues to investigate in
deceptive speech, frequency of ‘um’ may offer two
advantages in English-speaking forensic contexts. First,
when viewed as legitimate lexical terms, they lend
themselves to automation (as just like any other word they
can be identified and counted using basic part-of-speech
tagging systems) and, second, they may be somewhat
independent of the content of the communication. For
example, Newman et al. (2003) found that a number of
linguistic markers of deception identified in accounts about
abortion were more predictive within the topic than across
topics (e.g., first person pronouns, exclusive words, motion
verbs and negative emotion words) suggesting a
relationship between subject matter and language behaviour.
By contrast, um’s are more likely to be individual stylistic
markers (Shriberg, 2001) that are attached to the person
rather than the context and hence it is their relative use in
truth-telling versus deception that may provide clues to
veracity. Such context-independence is valuable in real-
world settings where the speech of the speaker cannot
always be constrained. Of course, the accompanying down-
side of speaker-dependent cues to deception, particularly in
automated systems, is the importance of establishing base-
line measures of the target variable before any demarcations
from this can be noted and interpreted.
Avenues for future research include investigation of
utterances such as ‘um’ in participants who are practiced
liars’ (e.g., one might compare poker players and non-poker
players using the laboratory-elicited methods described
here). It would also be interesting to experimentally
manipulate cognitive load using laboratory-elicited
methods. As suggested by Vrij, Fisher, Mann and Leal.
(2006) participants could be asked to engage in a secondary
(unrelated) cognitive task while being interviewed (i.e.,
while they are telling the truth and, also, while they are
lying) to more precisely examine the effects of cognitive
load on lying.
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... The acquisition methodology is based on [17], which consists in two interviews. In the first one, the valence and the arousal were evaluated. ...
... Therefore, dimension did not put any problem in any of the training or validation epochs. The final stage of the study is the analysis of tendencies regarding the most efficient combinations in terms of N 9 M. It must be stressed that the best combinations for the female-polynomial-pow3 are the tuples (19,12) and (20,14) for N and M, and in the case of the male-polynomial-pow3 these were (15,10) and (17,14), showing that they tend to be in the third quarter of N and in the second half of M. But this study would require a specific dedication in itself and is left for a future work line. ...
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Emotion detection is a hot topic nowadays for its potential application to intelligent systems in different fields such as neuromarketing, dialogue systems, friendly robotics, vending platforms and amiable banking. Nevertheless, the lack of a benchmarking standard makes it difficult to compare results produced by different methodologies, which could help the research community improve existing approaches and design new ones. Besides, there is the added problem of accurate dataset production. Most of the emotional speech databases and associated documentation are either privative or not publicly available. Therefore, in this work, two stress-elicited databases containing speech from male and female speakers were recruited, and four classification methods are compared in order to detect and classify speech under stress. Results from each method are presented to show their quality performance, besides the final scores attained, in what is a novel approach to the field of study.
... The acquisition methodology is based on [17], which consists in two interviews. In the first one, the valence and the arousal were evaluated. ...
... Therefore, dimension did not put any problem in any of the training or validation epochs. The final stage of the study is the analysis of tendencies regarding the most efficient combinations in terms of N 9 M. It must be stressed that the best combinations for the female-polynomial-pow3 are the tuples (19,12) and (20,14) for N and M, and in the case of the male-polynomial-pow3 these were (15,10) and (17,14), showing that they tend to be in the third quarter of N and in the second half of M. But this study would require a specific dedication in itself and is left for a future work line. ...
Chapter
Detecting and identifying emotions expressed in speech signals is a very complex task that generally requires processing a large sample size to extract intricate details and match the diversity of human expression in speech. There is not an emotional dataset commonly accepted as a standard test bench to evaluate the performance of the supervised machine learning algorithms when presented with extracted speech characteristics. This work proposes a generic platform to capture and validate emotional speech. The aim of the platform is collaborative-crowdsourcing and it can be used for any language (currently, it is available in four languages such as Spanish, English, German and French). As an example, a module for elicitation of stress in speech through a set of online interviews and other module for labeling recorded speech have been developed. This study is envisaged as the beginning of an effort to establish a large, cost-free standard speech corpus to assess emotions across multiple languages.
... Through Linear Discriminant Analysis based on 12 acoustic features, it was shown that it is possible to reach the three categories of neutral, depressive, stressed, highly stressed speech. Arciuli et al. (2009) followed suit and examined the frequency of use of the filler 'um' during lying versus truth-telling statements in two laboratory-elicited lies about a murder case. They found out that within-participants, false statements exhibited fewer instances of 'um' during lying compared to truth-telling. ...
... An alternative benchmark as suggested by Burgoon and Qin (2006) is the average sentence length 3 . Moreover, the idea of relating cognitive difficulty to filled pauses runs counter to the view held by Arciuli et al (2009), where false statements usually contain fewer 'um' instances than truthful statements. Finally, being a predictive study, Burgoon and her colleagues omitted to include two important aspects: (a) the minimum amount (or percentage) of each feature that should be available for a statement to be false and (b) a rating scale that could locate the degree of veracity. ...
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The present study addresses the problem of how the two US presidential candidates Donald Trump and Hillary Clinton use statements judged to be false by the Politifact site while delivering their campaign speeches. Two corpora of Clinton’s and Trump’s alleged lies were compiled. Each corpus contained 16 statements judged to be false or ridiculously untrue (‘pants on fire’) by the Pulitzer Prize Winner site Politifact. Some statements were accompanied by the video recordings where they appeared; others had no video recordings affiliated because they are either tweets or their events had not been recorded on Youtube or elsewhere. The present research made use of CBCA (Criteria-based Content Analysis) but as a stepping stone for building a new model of detecting lies in political discourse to suit the characteristics of campaign discourse. This furnished the qualitative dimension of the research. As for the quantitative dimension, data were analyzed using software, namely LIWC (Linguistic Inquiry & Word Count), and also focused on the content analysis of the deception cues that can be matched with the results obtained from computerized findings. When VSA (Voice Stress Analysis) was required, Praat was used. Statistical analyses were occasionally applied to reach highly accurate results. The study concluded that the New Model (NM) is not context-sensitive, being a quantitative one, and is thus numerically oriented in its decisions. Moreover, when qualitative analysis intervenes, especially in examining Politifact rulings, context plays a crucial role in passing judgements on deceptive vs. non-deceptive discourse.
... At face value, both possibilities seem equally persuasive. Yet, in the case of 'um', there is convergent evidence from both lowstakes laboratory-elicited lies (Arciuli, Mallard, & Villar, 2010;Arciuli, Villar, & Mallard, 2009;Benus, Enos, Hirschberg, & Shriberg, 2006) and one real-world high-stakes case study (Villar, Arciuli, & Mallard, 2012), where 'um' was measured as a stand-alone variable, to show that liars strategically reduce their use of 'um' during lying. From studies unrelated to deception, it is known that speakers are quite capable of successfully reducing their usage of 'um' via conscious control (Clark & Fox Tree, 2002;Kowal et al., 1997). ...
... Moreover, the effect size is large (d D .87). These findings are in line with those of previous studies which show a reduction in instances of 'um' during lying as opposed to truth-telling (Arciuli, Mallard, & Villar, 2010;Arciuli, Villar, & Mallard, 2009;Benus, Enos, Hirschberg, & Shriberg, 2006;Villar et al., 2012). These results provide important real-world evidence for the claim that humans can and do engage in behavioural control strategies with a view to appearing more credible. ...
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The aim of this study is to determine whether the presence of the interjection ‘um’ can distinguish between the deceptive and truthful speech of individuals who are practised in the art of impression management. A total of 50 truthful and 61 deceptive statements were extracted from the speech of celebrities participating in a televised comedy panel show where celebrity guests try to convince an opposing team of their truthfulness. Participants’ use of ‘um’ (measured as a percentage of the total word count of each statement) was analysed. The results show that, on average, ‘um’ was used almost three times as often in the speakers’ true statements compared to their false ones. A discriminant analysis revealed that the presence of ‘um’ is more effective than human judgement alone in determining veracity. These findings suggest that the presence of the filler ‘um’ in speech is useful in the identification of true versus false oral statements.
... Another reason for assuming that a heuristic is at play is that listeners' interpretations of disfluency may be inaccurate. Although listeners tend to associate disfluency with lying (Loy et al., 2016a;Zuckerman et al., 1981), some evidence suggests that, in production, disfluency occurs more frequently during truth-telling than during deception (Arciuli, Mallard, & Villar, 2010;Arciuli, Villar, & Mallard, 2009;Benus, Enos, Hirschberg, & Shriberg, 2006). DePaulo, Rosenthal, Rosenkrantz, and Green (1982) demonstrated a mismatch between disfluency as an actual and as a perceived cue to deception: The rates of filled pauses produced by speakers did not differ during descriptions they made about people whom they liked or disliked from descriptions made when they were asked to pretend to feel the opposite way about them. ...
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Where the veracity of a statement is in question, listeners tend to interpret disfluency as signaling dishonesty. Previous research in deception suggests that this results from a speaker model, linking lying to cognitive effort and effort to disfluency. However, the disfluency–lying bias occurs very quickly: Might listeners instead simply heuristically associate disfluency with lying? To investigate this, we look at whether listeners’ disfluency–lying biases are sensitive to context. Participants listened to a potentially dishonest speaker describe treasure as being behind a named object while viewing scenes comprising the referent (the named object) and a distractor. Their task was to click on the treasure’s suspected true location. In line with previous work, participants clicked on the distractor more following disfluent descriptions, and this effect corresponded to an early fixation bias, demonstrating the online nature of the pragmatic judgment. The present study, however, also manipulated the presence of an alternative, local cause of speaker disfluency: the speaker momentarily distracted by a car horn. When disfluency could be attributed to speaker distraction, participants initially fixated more on the referent, only later fixating on and selecting the distractor. These findings support the speaker modeling view, showing that listeners can take momentary contextual causes of disfluency into account.
... Different strategies can be found in the literature to evoke stress in speech. In this work, the protocol followed is the one described in [13] consisting, in the first place, in evaluating the arousal and valence about personal opinions related with very controversial social topics. Then the two topics with the higher score were selected. ...
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The current work gives a method to estimate alterations in speech caused by stress. This estimation is used as an indicator to detect deceptive speech. Truthful or neutral speech and deceptive speech were elicited by forcing to answer “hot questions” related with politics and society. Data were processed by using log-likelihood ratios and Fisher's linear discriminant analysis. Independent results for male and female are presented. The classification results are around 100% for neutral speech in both genders, while the best classification rate (67%) for stressed speech is achieved for females. In a first approach we have seen, that subjects tend to be more deceptive when the questions are related with gender issues, giving a politically correct answer instead of their true opinion.
Chapter
The concept of cognitive niche is useful to frame morality and violence in a naturalistic perspective. The first sections of this chapter aim at deepening our understanding of this concept, taking advantage of an evolutionary framework that is ideally linked to the considerations I have provided in chapter one, focused on the role of coalition enforcement in illustrating violence as a natural (animal and human) behavior.
Chapter
Laci Peterson was eight months pregnant when she disappeared on Christmas Eve in 2002. She was reported missing by her husband, Scott. Several months after her disappearance, her body and her son's fetus were found washed ashore in the San Francisco Bay. Her disappearance and murder, and the subsequent trial of her husband, captivated Americans. After a lengthy trial, her husband was convicted of first‐degree murder and sentenced to death. Legislation recognizing the killing of an unborn child as homicide was later created as a response to the violent act.
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Today’s battlefields are shifting to “denied areas”, where the use of U.S. Military air and ground assets is limited. To succeed, the U.S. intelligence analysts increasingly rely on available open-source intelligence (OSINT) which is fraught with inconsistencies, biased reporting and fake news. Analysts need automated tools for retrieval of information from OSINT sources, and these solutions must identify and resolve conflicting and deceptive information. In this paper, we present a misinformation detection model (MDM) which converts text to attributed knowledge graphs and runs graph-based analytics to identify misinformation. At the core of our solution is identification of knowledge conflicts in the fused multi-source knowledge graph, and semi-supervised learning to compute locally consistent reliability and credibility scores for the documents and sources, respectively. We present validation of proposed method using an open source dataset constructed from the online investigations of MH17 downing in Eastern Ukraine.
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We first describe a number of inter-related issues that need to be considered by the researcher when comparing frequencies of linguistic features in two or more corpora. We then describe the chi-squared and log-likelihood tests used in previous research for the comparison of word frequencies. Our focus, in this paper, is on the issue of reliability of the statistical tests, and we describe simulation experiments to compare the reliability of the chi- squared and log-likelihood statistics under conditions of different-sized corpora and probability of a word occurring in text. We observe that the Cochran rule provides a good guide to accuracy of both statistics in general, but in some cases it needs to be extended. We conclude by recommending higher cut-off values for the Cochran rule at the 5%, 1% and 0.1% levels. In order to extend applicability of the frequency comparisons to expected values of 1 or more, use of the log-likelihood statistic is preferred over the chi-squared statistic, at the 0.01% level. The trade-off for corpus linguists is that the new critical value is 15.13.
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The discourse marker use of the word like (‘we hitch a ride out of there with uh this like one crazy like music major guy’) is considered by many to be superfluously sprinkled into talk, a bad habit best avoided. But a comparison of the use of like in successive tellings of stories demonstrates that like can be anticipated in advance and planned into stories. In this way, like is similar to other words and phrases tellers recycle during story telling. The anticipation of like contrasted with the uses of other discourse markers such as oh, you know, and well, which almost never re-occurred in similar locations across tellings. Um and uh did sometimes re-occur; these uses are contrasted with like. Although discourse markers are generally used on the fly to handle various issues that come up in coordinating talk as it unfolds, like can be used as an integral part of the story -a marked contrast to the prevalent idea that likes are speech tics.
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All deception studies published to date have been laboratory studies. In such studies people lied only for the sake of the experiment, consequently the stakes were usually low. Although research has shown that most spontaneous lies told in real life are trivial, such studies tell us little about lies where the stakes are high (such as police/suspect interviews). In Study 1, we discuss the behaviour of an actual suspect while he was interviewed by the police in a murder case. Although the man initially denied knowing and killing the victim, substantial evidence obtained by the police showed that he was lying. On the basis of this evidence, the man confessed to killing the victim and was later convicted for murder. To our knowledge there has been no other study published that has analysed the behaviour of a liar in such a high-stake realistic setting. The analysis revealed several cues to deception. In Study 2, we exposed 65 police officers to six fragments (three truthful and three deceptive) of the interview with the murderer and asked them to indicate after each fragment whether the man was lying or not. The findings revealed that the participants were better at detecting truths (70% accuracy) than lies (57% accuracy). We also found individual differences among observers, with those holding popular stereotypical views on deceptive behaviour, such as ‘liars look away’ and ‘liars fidget’ performing least effectively as lie catchers. Copyright © 2001 John Wiley & Sons, Ltd.
Article
The use of swearwords has hardly been investigated scientifically. Virtually nothing is known about the efficacy of swearing. The present studies set out to investigate whether the inclusion of swearwords in a testimony increases the believability of that statement. In study 1, respondents were simply asked whether they believed that using swearwords is a sign of credibility, a sign of deceit, or neither. In the second and third study, participants had to read fictitious testimonies of a suspect and a victim, respectively. Participants were exposed to testimonies with or without swearwords. The results suggested that people self-reported to find swearwords a sign of deceit (study 1), but when actually confronted with a statement, the opposite turned out to be the case (studies 2 and 3). That is, testimonies containing swearwords were perceived as more credible than swearword-free testimonies. Hence it is concluded that swearing increases believability of statements.
Article
Examined the concepts of powerful and powerless speech styles by investigating evaluative reactions of 120 undergraduates to hedges and hesitations in a simulated courtroom trial context. Issues addressed were whether hedges, hesitations, and respondent sex would interact to affect evaluations of a speaker and whether these language variables affected perceptions of guilt. A low level of hedges and hesitations produced the most positive evaluations of authoritativeness and attractiveness. High levels of hesitations and hedges produced more negative evaluations of guilt. (PsycINFO Database Record (c) 2012 APA, all rights reserved)