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Open Journal of Psychiatry, 2016, 6, 86-94
Published Online January 2016 in SciRes. http://www.scirp.org/journal/ojpsych
http://dx.doi.org/10.4236/ojpsych.2016.61010
How to cite this paper: Værøy, H., Western, E. and Andersson, S. (2016) The Link between Facets of Impulsivity and Ag-
gression in Extremely Violent Prisoners. Open Journal of Psychiatry, 6, 86-94.
http://dx.doi.org/10.4236/ojpsych.2016.61010
The Link between Facets of Impulsivity and
Aggression in Extremely Violent Prisoners
Henning Værøy1*, Elin Western2, Stein Andersson3
1Department of Psychiatric Research and Development, Akershus University Hospital, Loerenskog, Norway
2Department of Pediatric Neuroscience, Oslo University Hospital, Rikshospitalet, Norway
3Institute of Psychology, University of Oslo, Oslo, Norway
Received 19 November 2015; accepted 16 January 2016; published 19 January 2016
Copyright © 2016 by authors and Scientific Research Publishing Inc.
This work is licensed under the Creative Commons Attribution International License (CC BY).
http://creativecommons.org/licenses/by/4.0/
Abstract
Evidence is growing that aggressive behavior and impulsivity have subgroups. The subscales of
the Urgency, Premeditation, Perseverance and Sensation seeking (UPPS) impulsivity scale and the
Bryant and Smith shortened and refined version of the Aggression Questionnaire were used to
describe and compare impulsive and aggressive behavior in extremely violent and aggressive
male inmates and non-violent healthy male controls. The Mann-Whitney test showed that there
was a significant difference (p < 0. 006) in the total UPPS impulsivity scale scores between the ag-
gressive inmates and the controls. The subscales revealed that this difference was based mainly
on the urgency score (p < 0. 003). On the aggression subscales, the inmates scored significantly
higher for physical aggression than the controls (p < 0.001), but no significant difference was seen
between inmates and controls for verbal aggression, anger and hostility, although the exact p-
value was very close to statistical significance at 0.054. Regression analysis revealed a strong rela-
tionship between urgency and the aggression subscales hostility (p = 0.0004) and anger (p = 0.003)
and that urgency was also linked to symptoms of anxiety (p = 0.008). Finally, a statistically signifi-
cant link was found between both hostility (p = 0.0003) and anger (p = 0.002) and symptoms of
anxiety. The highly selected subgroup of extremely violent criminals in this study were more
physically aggressive than non-violent controls, with urgency as the driving feature in their im-
pulsive behavior, and hostility, anger and symptoms of anxiety as underlying traits.
Keywords
UPPS, Aggression, Impulsivity, Inmates, Prisoners
*
Corresponding author.
H. Værøy et al.
87
1. Introduction
The biological complexity of the development of aggression is partly illustrated by studies showing that child-
hood trauma and genetic polymorphism may interact and increase the risk for aggressive behavior in male pris-
on populations [1]. Lower amygdala volume is associated with male aggression and the development of future
violence in children [2]. Changes in testosterone levels are known to modulate aggressive behavior, and de-
creasing levels of cortisol over time are a predictor for persistent aggression in highly aggressive adolescents [3].
Psychologically, competition may in some cases represent a situation in which aggressive behavior may follow,
but only in men with low trait anxiety [4]. Attempts to classify aggression have been made over the years, and
impulsive (reactive) aggression as a disorder has been included in the DSM diagnostic system since the first edi-
tion [5] [6]. Impulsive aggression seems heritable by genetic transmission [7] and it is strongly predicted by
cognitive and affective empathy [8]. Impulsive aggression does not predict violence recidivism as opposed to
premeditated aggression [9]. Impulsive aggression often occurs in response to perceived provocation [10] whe-
reas premeditated or proactive aggression is goal-directed, and carried out unemotionally [11] [12].
The relationship between impulsivity and aggression has long been established and is recognized in terms
such as “impulsive aggression”. Less is known about the relationship between impulsivity and anxiety. Some
claim that both have clear relations to aggression [13]. Others see anxiety as a possible mediator in settings
where both impulsivity and aggression interact [14] or conclude that impulsivity has the same effect on aggres-
sion, in this case physical, regardless of the level of anxiety [15]. Hostile impulses have been included among
known risk-prone activities for social anxiety disorder in response to impulsive decision-making [16]. Impulsiv-
ity has been linked to 2 different classes of social anxiety disorder, one of which is associated with higher levels
of anger, aggression, sexual impulsivity and substance abuse [17] [18].
It is not known why some socially anxious individuals are vulnerable to become aggressors, but culture and
honor-concerns are known to influence this, as can a feeling of being persecuted, since the latter is significantly
linked to an aggressive attitude [19]. Angry or anxious persons display a more aggressive attitude than persons
in a normal mood state [20] and anxiety is most likely the mediator when, for example, physical and sexual ag-
gression towards a partner are used, as in cases of anticipated infidelity [14].
Several theories have been proposed to explain and understand impulsive behavior, but much is still unclear
[21]-[25].
In Emil Kraepelin’s Lehrbuch der Psychiatrie (Textbook of Psychiatry, 1904) [26], the term impulsive insan-
ity refers to often purposeless, unpremeditated, irresistible impulses, often morbid, to destroy and kill. In fact,
there is a high prevalence of both recurrent suicide attempts (87%) and hypomanic episodes (62%), especially
where impulsivity co-exists with anxiety [27].
Perhaps the best known and most frequently used scale for measuring impulsivity is the Barratt Impulsiveness
Scale (BIS), [28]-[32]. The Five-Factor Model of Personality [33] introduces the possibility to better understand
and position the different concepts of impulsivity, and to add clarity to the assortment of impulsivity measures.
This led to the development of the UPPS impulsivity scale [34] which focuses on facets of impulsivity common
across the different measures.
We thought that the Buss Perry Aggression Questionnaire (AQ) [35] in its Swedish version, the Aggression
Questionnaire in the Revised Swedish Version (AQ-RSV), [36], and Bryant and Smith-refined Aggression
Questionnaire subscales (BS-rAQ) [37] would reveal important nuances in our population of extremely aggres-
sive individuals, thereby providing us with new information.
In the present study the impulsivity subscales urgency, premeditation, perseverance and sensation seeking
were applied together with the aggression subscales hostility, physical and verbal aggression and anger. The aim
of the study was to see how the different subscales performed against each other in a highly selected population
of extremely violent inmates and to establish whether the use of subscales provided new information. We were
unable to find any other publications on a similar population assessed using the subscales we applied here.
2. Methods
This study was conducted in two stages. Recruitment of the inmates and the first group of controls was done in
2011 and 2012 and the second control group in 2014.
H. Værøy et al.
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2.1. Study Population
2.1.1. Inmates
To be included as a study subject in this study a long-term sentence due to extremely violent crime was a pre-
requisite. Sixteen violent male inmates, mean age 41.9 + 11.9 (SD) years, the majority in preventive detention,
were recruited from a high security prison outside Oslo, except for one who had recently been released but still
agreed to participate. He was later re-arrested and charged following new episodes with violent behaviour. Fif-
teen of the 16 violent inmates were assessed using the AQ-RSV [36] and the UPPS [34]; one inmate did not
complete the questionnaire. Eleven of the16 inmates had committed at least one murder or had attempted to
commit murder, and 4 had committed severely violent crimes with a sex-related component. The main features
of the extremely brutal violence were rape, molestation or grievous bodily harm. Inmates diagnosed with paedo-
philia were not included in this study. One inmate had participated in gang-related violence, killing one person.
Fifteen of the inmates were serving long-term sentences, the majority in preventive detention.
In Norway, the imposition of preventive detention indicates that the court considers the defendant at a high
risk for reoffending, and therefore as an imminent threat to society. According to Norwegian law, after having
served a minimum term not exceeding 10 years, prisoners in preventive detention may ask the court to recon-
sider their case.
Before inclusion, the inmates were thoroughly informed about the inclusion and exclusion criteria. Among the
15 prisoners, no serious mental illness was reported or found when clinically screened for psychiatric history
and current disorders at the time of the first visit.
The process of recruiting inmates who have committed very violent and aggressive acts is complex and chal-
lenging. Furthermore, in Norway, the total number of excessively violent inmates is much smaller than in coun-
tries with large populations. Severe security measures usually apply and the inmates who eventually agreed to
participate represent a highly selected population. In the present study, the 15 high security level inmates were
assessed using the AQ-RSV [36]. Having identified and extrapolated the 12 questions in the AQ-RSV that cor-
respond to those forming the BS-rAQ [37], this paper presents the BS-rAQ scores from 15 extremely violent
inmates sentenced to long-term imprisonment, and their scores on a translated, authorized, but unpublished,
Norwegian version of the UPPS impulsivity scale [34].
2.1.2. Controls
In this study, two healthy male control (HC) groups were randomly recruited from the general population. The
first HC group (HC-I) of 21 subjects, mean age 41.8 + 10.4 (SD) years old, was recruited at an early stage of the
study. The second group (HC-II) of 37 healthy males was recruited as controls for the UPPS. The mean age of
the HC-II group was 39.5 + 10.1 (SD) years. The HC-II group was also assessed using the BS-rAQ and the
Hospital Anxiety and Depression Scales (HAD), and was added to the already existing healthy male control
group, HC-I. Consequently, aggression and anxiety scores from an HC group of 58 subjects were available for
comparison. None of the control subjects had any history of violence and reported no prior or concurrent psy-
chiatric or neurological disorders.
2.2. Questionnaires
The self-rating Buss-Perry Aggression Questionnaire (AQ) [35] with its 4 subscales describing verbal and
physical aggression, anger, and hostility is extensively used and has been translated into several languages, in-
cluding a revised Swedish version (AQ-RSV) [36].
1) The Aggression Questionnaire-Revised Swedish Version (AQ-RSV)
The Swedish version of the AQ [36] was developed for research into clinical aggression based on the US ver-
sion of the AQ [35]. For validation, the test was mailed to 781 randomly selected individuals aged 20 - 40 years.
Of these, scores from 497 test persons were evaluable (64%). The results from the American and the Swedish
versions were comparable for the correlations between the four aggression subscales and had alpha coefficients
indicating internal consistency. The Swedish and Norwegian cultures and languages are very close, which
means that we did not expect any major problems applying the AQ-RSV directly to a Norwegian population.
2) The Bryant and Smith shortened and refined Aggression Questionnaire (BS-rAQ).
Bryant and Smith [37] introduced a 12-question refined measurement model (BS-rAQ) of the original AQ
H. Værøy et al.
89
[35]. Due to overlap between what the subscales actually measured and low common variance, the AQ was
consequently refined by Bryant and Smith [37].
The inmates’ individual AQ-RSV scores corresponding to the 12 questions forming the BS-rAQ were se-
lected for the BS-rAQ subscale analysis in this study.
3) The UPPS impulsivity scale.
Whiteside and Lynam [34] identified 4 distinct facets of personality that had been frequently confused and
commonly referred to as impulsivity. These facets, urgency, premeditation, perseverance and sensation-seeking,
form the UPPS impulsivity behavior scale [34].
The Hospital Anxiety and Depression (HAD) scale [38] is a 14 item self-report measure with two subscales,
each of 7 items for detecting states of depression and anxiety. In this study, to qualify for clinically significant
anxiety and depression, a cut-off point of >8 was chosen for both the anxiety and depression subscales.
The inmates were assessed using the UPPS [34], the AQ-RSV [36] and the HAD scale sitting at a table in a
room in the visiting area outside their departments at the prison.
2.3. Statistics
All statistical analyses (linear and non-linear regression analysis, Mann-Whitney [MW] test, Student’s t-test and
the Kolmogorov-Smirnov [KS] test) were performed using GraphPad Software, Inc., La Jolla, CA 92037 USA.
A p-value < 0.05 was considered statistically significant.
2.4. Ethics
The study was approved by the Norwegian Regional Ethics Committee-approval number 2010/792.
3. Results
3.1. Mann-Whitney and Kolmogorov-Smirnov Tests
The MW test showed a significant difference (p < 0.006) in the total UPPS impulsivity scale scores between the
aggressive inmates and the HC-II group. The result in the KS test was p < 0.003. Looking at the 4 subscales,
only urgency showed a statistically significant difference (p < 0.003) in the MW test, and a p-value of 0.02 in
the KS test. There were no differences with a p-level ≤ 0.05 between inmates and HC-II controls for the re-
maining 3 UPPS subscales.
The total number of controls who completed the BS-rAQ was 58. The MW test showed that the inmates were
significantly more physically aggressive than the controls (p < 0.001) and the KS test gave a p-value of 0.002 for
the same difference. No significant difference was seen for the subscales verbal aggression, anger and hostility
in the MW test, but for hostility the exact p-value of 0.054 was very close. The KS test, in this case, gave a
p-value of 0.140. Furthermore, the KS test showed statistical significance (0.047) for anger but not for verbal
aggression.
3.2. Regression Analysis
3.2.1. Impulsivity and Aggression
Linear regression analyses between the inmates’ urgency scores and hostility and anger yielded statistically sig-
nificant relationships (Figure 1).
3.2.2. Impulsivity and Symptoms of Anxiety
Figure 2 displays the linear regression between the inmates’ individual urgency scores and HAD A subscale
scores for anxiety (p = 0.008). No statistically significant relationship was seen between any UPPS impulsivity
scales and depression, or between the anxiety scores and the 3 remaining UPPS subscales.
3.2.3. Aggression and Symptoms of Anxiety
Linear regression between hostility and anger and the HAD A subscale also yielded statistically significant rela-
tionships as seen in Figure 3(a) (hostility p = 0.0003) and Figure 3(b) (anger p = 0.002).
Four inmates scored equal to or above the cut-off score of ≥ 8 on the anxiety subscale and 1 inmate scored
H. Værøy et al.
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(a) (b)
Figure 1. (a) Displays the linear regression between the inmates’ urgency and hostility scores; p = 0.0004, Y = 2,762*X –
2,328. (b) Displays the linear regression between the inmates’ urgency and anger scores; p = 0.003, Y = 2,625*X – 2,724.
Linear regression revealed no statistically significant relationships between premeditation, perseverance, sensation-seeking,
and physical and verbal aggression.
Figure 2. Shows the linear regression between urgency and HAD A, Y = 5,592*X – 6,957.
(a) (b)
Figure 3. (a) Shows the linear regression between hostility and HAD A, Y = 1,988*X – 2,091 and (b) shows the linear re-
gression between anger and HAD A, Y = 1,679*X + 0.5311.
above the cut-off score of ≥ 8 for depression. Only a small proportion of the inmates therefore showed levels of
anxiety and depression that would normally elicit follow-up of the clinical state.
4. Discussion
Brutality and violent aggression represent a menace to society. Following blind and unpredicted violence, the
questions of whether it could have been predicted and therefore avoided are frequently asked. In forensic psy-
chiatry, the question of whether an aggressive act can be classified as impulsive or not is rarely met with an an-
H. Værøy et al.
91
swer without reservations. The link between aggression and impulsivity is not clear, but there are studies de-
scribing an association between the two [10] [15]. The findings of the present study in extremely violent and
brutal criminals do not confirm that higher impulsivity scores are associated with higher levels of reported
physical aggression [15]. Our findings do, however, show that there is a significant relationship between impul-
sivity and aggression as demonstrated by the impulsivity subscale urgency and the aggression subscales hostility
and anger in the two assessment questionnaires we used. Furthermore, the level of urgency among our violent
criminals is significantly greater than in controls, indicating that individuals in our highly selected study group
may carry a higher risk of committing violent acts because of the level of urgency. The difference between the
two current study groups’ aggression scores for hostility and anger only just achieved statistical significance,
possibly influenced by factors such as low sample size and lack of homogeneity. It must also be borne in mind
that our population of inmates is different from the populations for whom the questionnaire is developed. Bryant
and Smith based their study on 5 samples of undergraduates of both genders [37].
The UPPS is constructed based on information from 437 undergraduates, mostly women enrolled in an intro-
ductory psychology course [34] and has demonstrated its usefulness as a predictor as well as a potential tool for
distinguishing between certain forms of aggression [39]. The present significant relationship between urgency
and hostility supports observations showing a link between negative urgency and hostile attributes [40] and
studies concluding that negative urgency may account for a significant variance in aggression [41]. No signifi-
cant relationships between UPPS facets and aggressive responses are, however, found in a more recent study [42]
examining the relationship between the UPPS facets of impulsivity and aggressive responses from a response
choice aggression paradigm in college undergraduates.
We also observed a statistically significant relationship between impulsivity, i.e. urgency and symptoms of
anxiety, and linear regression analysis shows a direct link between anxiety and urgency, but not between anxiety
and the other UPPS impulsivity measures. Some studies have shown that patients with anxiety disorders without
a lifetime history of comorbid major mood episodes have greater trait and state impulsivity than controls [43]. In
conditions with substance use disorders, others have shown that the total scores on the Barrat Impulsivity Scale
(BIS) [11] [44] may predict violence [45]. Furthermore, anxiety symptoms seem to account for the link between
reactive aggression and sleep problems among Latino adolescents [46]. Taken together, there is growing evi-
dence for the existence of subgroups of aggression, which in some anxiety and impulsivity levels may identify
at-risk behavior [27]. Complicating matters further, subtypes of social anxiety disorder (SAD) have been recog-
nized [47].
In our study, we also find that the inmates’ scores on the aggression subscales hostility and anger, but not
physical and verbal aggression, correlate with their scores for symptoms of anxiety on the HAD A subscale. No
statistical significance is found when testing the relationship between the inmates’ scores on the aggression sub-
scales against HAD D symptoms of depression. A link between anxiety and aggression as indicated by the pre-
sent results represents a platform shared with some previous observations, e.g. that persons with an angry or an-
xious mood state display a more aggressive attitude than those with a neutral mood [20], and with the observa-
tion of a correlation between the duration of anxiety and anger and hostility in patients with panic disorder [48].
We are unable to offer an explanation for the lack of correlation between the inmates’ symptoms scores for
anxiety and scores for physical or verbal aggression in this study, but a lack of clinically significant anxiety
cannot be ruled out. A relationship between anxiety and aggression may not necessarily be direct as indicated by
studies showing that anxiety symptoms seem to account for the link between reactive aggression and sleep
problems [46] and that anxiety may act as a mediator in some cases of physical aggression [14].
Although our results are vulnerable to interfering factors, the chosen approach has resulted in what we believe
is a strength of this study. To a certain extent the results reflect and support the existence of aggressive sub-
groups as described elsewhere. In this case an extremely brutal and aggressive group with the personality cha-
racteristics urgency, hostility and anger.
A complicating factor when identifying possible subgroups is that different studies often refer to the use of
different scales applied on different populations, which impedes direct comparison. Different scales imply that
different issues may have been addressed in the construction of the scales with direct consequences for what is
actually measured. Applied to our highly selected population, the respective scales most likely contain different
interfering biases. Therefore, beyond pointing in a direction which we believe is worth pursuing in future re-
search, we are at present not comfortable with making more firm conclusions based on the results of our linear
regression analyses.
H. Værøy et al.
92
In studies like ours, there will always be questions regarding the validity of the results, especially when based
on an individual’s self-scores. The fact that all inmates included in the study population classed their childhood
as good is of concern, since we have gathered strong evidence over the years that childhood trauma represents a
risk factor for the development of aberrant behaviour later in life. Childhood physical punishment (CPP) has
been associated with a number of negative psychosocial outcomes in adulthood [49], some of which are in-
creased aggressiveness [50] [51], phobias, anxiety, schizotypal personality, and alcohol and drug abuse [52]. In
view of the inmates’ positive assessments on their childhoods, future research should also consider the possible
interference of sublimation, a defence mechanism where socially unacceptable impulses are consciously trans-
formed into socially acceptable actions. It is known that acting out and less use of sublimation predicts higher
levels of anxiety [53] and that CPP may cause internalized anger and negativity towards others [49].
Some of the limitations of this study have already been addressed. The majority of the inmates included re-
ported use of both legal and illegal drugs and stimulants. We were unable to gather detailed information on this
to create a group-based overview. Classification of the aggressive acts based on information from the inmates
makes it possible to deduce that only one of the severe criminal types of behaviour described could be classified
as premeditated aggression, and the rest as impulsive. Strengths of our study were that the group of inmates in-
cluded was relatively homogenous from a crime severity point of view-all having shown their potential for bru-
tality.
To conclude, we see growing evidence suggesting that the use of subscales as in this study would be of bene-
fit when trying to distinguish between different forms of aggression and impulsivity.
Acknowledgements
HV thanks Alvhilde Eliassens Research Foundation for financial support. The authors thank Alistair Reeves for
help with the language.
References
[1] Gorodetsky, E., et al. (2014) The Interactive Effect of MAOA-LPR Genotype and Childhood Physical Neglect on Ag-
gressive Behaviors in Italian Male Prisoners. Genes, Brain and Behavior, 13, 543-549.
http://dx.doi.org/10.1111/gbb.12140
[2] Pardini, D.A., et al. (2014) Lower Amygdala Volume in Men Is Associated with Childhood Aggression, Early Psy-
chopathic Traits, and Future Violence. Biological Psychiatry, 75, 73-80.
http://dx.doi.org/10.1016/j.biopsych.2013.04.003
[3] Platje, E., et al. (2013) Longitudinal Associations in Adolescence between Cortisol and Persistent Aggressive or
Rule-Breaking Behavior. Biological Psychology, 93,132-137. http://dx.doi.org/10.1016/j.biopsycho.2013.01.002
[4] Norman, R.E., et al. (2014) Trait Anxiety Moderates the Relationship between Testosterone Responses to Competition
and Aggressive Behavior. Adaptive Human Behavior and Physiology, 1-13.
[5] American Psychiatric Association, W.D. (1952) Diagnostic and Statistical Manual of Mental Disorders.
[6] Coccaro, E.F. (2012) Intermittent Explosive Disorder as a Disorder of Impulsive Aggression for DSM-5. American
Journal of Psychiatry, 169, 577-588. http://dx.doi.org/10.1176/appi.ajp.2012.11081259
[7] Dorfman, H.M., Meyer-Lindenberg, A. and Buckholtz, J.W. (2014) Neurobiological Mechanisms for Impulsive-Ag-
gression: The Role of MAOA.
[8] Gina, G., et al. (2014) Proactive and Reactive Aggression and Cognitive and Affective Empathy among Students in
Middle Childhood. International Journal of School and Cognitive Psychology, 1, 2.
[9] Swogger, M.T. et al. (2014) Impulsive versus Premeditated Aggression in the Prediction of Violent Criminal Recidiv-
ism. Aggressive Behavior.
[10] Stanford, M.S., Greve, K.W. and Dickens Jr., T.J. (1995) Irritability and Impulsiveness: Relationship to Self-Reported
Impulsive Aggression. Personality and Individual Differences, 19, 757-760.
http://dx.doi.org/10.1016/0191-8869(95)00144-U
[11] Barratt, E.S., Stanford, M.S., Dowdy, L., Liebman, M.J. and Kent, T.A. (1999) Impulsive and Premeditated Aggression:
A Factor Analysis of Self-Reported Acts. Psychiatry Research, 86, 163-173.
http://dx.doi.org/10.1016/S0165-1781(99)00024-4
[12] Stanford, M.S., Houston, R.J., Mathias, C.W., Villemarette-Pittman, N.R., Helfritz, L.E. and Conklin, S.M. (2003)
Characterizing Aggressive Behavior. Assessment, 10, 183-190. http://dx.doi.org/10.1177/1073191103010002009
H. Værøy et al.
93
[13] Perugi, G., Del Carlo, A., Benvenuti, M., Fornaro, M., Toni, C., Akiskal, K., Dell’Osso, L. and Akiskal, H. (2011)
Impulsivity in Anxiety Disorder Patients: Is It Related to Comorbid Cyclothymia? Journal of Affective Disorders, 133,
600-606. http://dx.doi.org/10.1016/j.jad.2011.04.033
[14] Arnocky, S., Sunderani, S., Gomes, W. and Vaillancourt, T. (2014) Anticipated Partner Infidelity and Men’s Intimate
Partner Violence: The Mediating Role of Anxiety. Evolutionary Behavioral Sciences, 9, 186-196.
[15] Hatfield, J. and Dula, C.S. (2014) Impulsivity and Physical Aggression: Examining the Moderating Role of Anxiety.
The American Journal of Psychology, 127, 233-243. http://dx.doi.org/10.5406/amerjpsyc.127.2.0233
[16] Kashdan, T.B., Collins, R.L. and Elhai, J.D. (2006) Social Anxiety and Positive Outcome Expectancies on Risk-Taking
Behaviors. Cognitive Therapy and Research, 30, 749-761. http://dx.doi.org/10.1007/s10608-006-9017-x
[17] Kashdan, T.B., McKnight, P.E., Richey, J.A. and Hofmann, S.G. (2009) When Social Anxiety Disorder Co-Exists with
Risk-Prone, Approach Behavior: Investigating a Neglected, Meaningful Subset of People in the National Comorbidity
Survey-Replication. Behaviour Research and Therapy, 47, 559-568. http://dx.doi.org/10.1016/j.brat.2009.03.010
[18] Kashdan, T.B. and McKnight, P.E. (2010) The Darker Side of Social Anxiety: When Aggressive Impulsivity Prevails
over Shy Inhibition. Current Directions in Psychological Science, 19, 47-50.
http://dx.doi.org/10.1177/0963721409359280
[19] Howell, A.N., Buckner, J.D. and Weeks, J.W. (2014) Culture of Honour Theory and Social Anxiety: Cross-Regional
and Sex Differences in Relationships among Honour-Concerns, Social Anxiety and Reactive Aggression. Cognition
and Emotion, 29, 568-577.
[20] Nederlof, A.F., Muris, P. and Hovens, J.E. (2014) Anger, Anxiety, and Feelings of Delusional Threat as Predictors of
Aggressive Attitudes: An Experimental Mood Induction Study in a Non-Clinical Sample. Personality and Individual
Differences, 57, 25-30. http://dx.doi.org/10.1016/j.paid.2013.09.006
[21] Gray, J.A. (1987) The Psychology of Fear and Stress. CUP Archive, Cambridge.
[22] Dickman, S.J. (1990) Functional and Dysfunctional Impulsivity: Personality and Cognitive Correlates. Journal of Per-
sonality and Social Psychology, 58, 95-102. http://dx.doi.org/10.1037/0022-3514.58.1.95
[23] Wallace, J.F., Newman, J.P. and Bachorowski, J.-A. (1991) Failures of Response Modulation: Impulsive Behavior in
Anxious and Impulsive Individuals. Journal of Research in Personality, 25, 23-44.
http://dx.doi.org/10.1016/0092-6566(91)90003-9
[24] Zuckerman, M., Kuhlman, D.M. and Thornquist, M. (1991) Five (or Three) Robust Questionnaire Scale Factors of
Personality without Culture. Personality and Individual Differences, 12, 929-941.
http://dx.doi.org/10.1016/0191-8869(91)90182-B
[25] Newman, J.P. and Wallace, J.F. (1993) Diverse Pathways to Deficient Self-Regulation: Implications for Disinhibitory
Psychopathology in Children. Clinical Psychology Review, 13, 699-720.
http://dx.doi.org/10.1016/S0272-7358(05)80002-9
[26] Kraepelin, E. and Defendorf, A.R. (1904) Clinical Psychiatry: A Text-Book for Students and Physicians: Abstracted
and Adapted from the 6th German Edition of Kraepelin’s “Lehrbuch Der Psychiatrie”. Macmillan, London.
[27] Askénazy, F.L., Sorci, K., Benoit, M., Lestideau, K., Myquel, M. and Lecrubier, Y. (2003) Anxiety and Impulsivity
Levels Identify Relevant Subtypes in Adolescents with At-Risk Behavior. Journal of Affective Disorders, 74, 219-227.
http://dx.doi.org/10.1016/S0165-0327(02)00455-X
[28] Barratt, E.S. (1993) Impulsivity: Integrating Cognitive, Behavioral, Biological, and Environmental Data.
[29] Gerbing, D.W., Ahadi, S.A. and Patton, J.H. (1987) Toward a Conceptualization of Impulsivity: Components across
the Behavioral and Self-Report Domains. Multivariate Behavioral Research, 22, 357-379.
http://dx.doi.org/10.1207/s15327906mbr2203_6
[30] Patton, J.H., Stanford, M.S. and Barratt, E.S. (1995) Factor Structure of the Barratt Impulsiveness Scale. Journal of
Clinical Psychology, 51, 768-774.
http://dx.doi.org/10.1002/1097-4679(199511)51:6<768::AID-JCLP2270510607>3.0.CO;2-1
[31] Stanford, M.S. and Barratt, E.S. (1992) Impulsivity and the Multi-Impulsive Personality Disorder. Personality and In-
dividual Differences, 13, 831-834. http://dx.doi.org/10.1016/0191-8869(92)90057-V
[32] Zuckerman, M. (1994) Behavioral Expressions and Biosocial Bases of Sensation Seeking. Cambridge University Press,
Cambridge.
[33] Costa Jr., P.T. and McCrae, R.R. (1990) Personality Disorders and the Five-Factor Model of Personality. Journal of
Personality Disorders, 4, 362-371. http://dx.doi.org/10.1521/pedi.1990.4.4.362
[34] Whiteside, S.P. and Lynam, D.R. (2001) The Five Factor Model and Impulsivity: Using a Structural Model of Perso-
nality to Understand Impulsivity. Personality and Individual Differences, 30, 669-689.
http://dx.doi.org/10.1016/S0191-8869(00)00064-7
H. Værøy et al.
94
[35] Buss, A.H. and Perry, M. (1992) The Aggression Questionnaire. Journal of Personality and Social Psychology, 63,
452-459. http://dx.doi.org/10.1037/0022-3514.63.3.452
[36] Prochazka, H. and Ågren, H. (2001) Aggression in the General Swedish Population, Measured with a New Self-Rating
Inventory: The Aggression Questionnaire—Revised Swedish Version (AQ-RSV). Nordic Journal of Psychiatry, 55,
17-23. http://dx.doi.org/10.1080/080394801750093661
[37] Bryant, F.B. and Smith, B.D. (2001) Refining the Architecture of Aggression: A Measurement Model for the Buss-
Perry Aggression Questionnaire. Journal of Research in Personality, 35, 138-167.
http://dx.doi.org/10.1006/jrpe.2000.2302
[38] Zigmond, A.S. and Snaith, R.P. (1983) The Hospital Anxiety and Depression Scale. Acta Psychiatrica Scandinavica,
67, 361-370. http://dx.doi.org/10.1111/j.1600-0447.1983.tb09716.x
[39] Derefinko, K., DeWall, C.N., Metze, A.V., Walsh, E.C. and Lynam, D.R. (2011) Do Different Facets of Impulsivity
Predict Different Types of Aggression? Aggressive Behavior, 37, 223-233. http://dx.doi.org/10.1002/ab.20387
[40] Lynam, D.R. and Miller, J.D. (2004) Personality Pathways to Impulsive Behavior and Their Relations to Deviance:
Results from Three Samples. Journal of Quantitative Criminology, 20, 319-341.
http://dx.doi.org/10.1007/s10940-004-5867-0
[41] Miller, J., Flory, K., Lynam, D. and Leukefeld, C. (2003) A Test of the Four-Factor Model of Impulsivity-Related
Traits. Personality and Individual Differences, 34, 1403-1418. http://dx.doi.org/10.1016/S0191-8869(02)00122-8
[42] Seibert, L.A., Miller, J.D., Pryor, L.R., Reidy, D.E. and Zeichner, A. (2010) Personality and Laboratory-Based Ag-
gression: Comparing the Predictive Power of the Five-Factor Model, BIS/BAS, and Impulsivity across Context. Jour-
nal of Research in Personality, 44, 13-21. http://dx.doi.org/10.1016/j.jrp.2009.09.003
[43] Del Carlo, A., Benvenuti, M., Fornaro, M., Toni, C., Rizzato, S., Swann, A.C., Dell’Osso, L. and Perugi, G. (2012)
Different Measures of Impulsivity in Patients with Anxiety Disorders: A Case Control Study. Psychiatry Research, 197,
231-236. http://dx.doi.org/10.1016/j.psychres.2011.09.020
[44] Barratt, E.S. (1959) Anxiety and Impulsiveness Related to Psychomotor Efficiency. Perceptual and Motor Skills, 9,
191-198. http://dx.doi.org/10.2466/pms.1959.9.3.191
[45] Zhou, J., Witt, K., Chen, C., Zhang, S., Zhang, Y., Qiu, C., Cao, L. and Wang, X. (2014) High Impulsivity as a Risk
Factor for the Development of Internalizing Disorders in Detained Juvenile Offenders. Comprehensive Psychiatry, 55,
1157-1164. http://dx.doi.org/10.1016/j.comppsych.2014.03.022
[46] Fite, P.J., Becker, S.P., Rubens, S.L. and Cheatham-Johnson, R. (2014) Anxiety Symptoms Account for the Link be-
tween Reactive Aggression and Sleep Problems among Latino Adolescents. Child & Youth Care Forum, 44, 343-354.
[47] Mortberg, E., Tillfors, M., van Zalk, N. and Kerr, M. (2014) An Atypical Anxious-Impulsive Pattern of Social Anxiety
Disorder in an Adult Clinical Population. Scandinavian Journal of Psychology, 55, 350-356.
http://dx.doi.org/10.1111/sjop.12117
[48] Sugaya, N., Yoshida, E., Yasuda, S., Tochigi, M., Takei, K., Otowa, T., et al. (2015) Anger Tendency May Be Asso-
ciated with Duration of Illness in Panic Disorder. BioPsychoSocial Medicine, 9, 6.
http://dx.doi.org/10.1186/s13030-015-0035-3
[49] Björkqvist, K. and Österman, K. (2014) Does Childhood Physical Punishment Predispose to a “Victim Personality”.
Pediatrics & Therapeutics, 4, 190.
[50] Gershoff, E.T. (2002) Corporal Punishment by Parents and Associated Child Behaviors and Experiences: A Meta-
Analytic and Theoretical Review. Psychological Bulletin, 128, 539-579.
http://dx.doi.org/10.1037/0033-2909.128.4.539
[51] Straus, M.A. (1991) Discipline and Deviance: Physical Punishment of Children and Violence and Other Crime in
Adulthood. Social Problems, 38, 133-154. http://dx.doi.org/10.2307/800524
[52] Afifi, T.O., Mota, N.P., Dasiewicz, P., MacMillan, H.L. and Sareen, J. (2012) Physical Punishment and Mental Dis-
orders: Results from a Nationally Representative US Sample. Pediatrics, 130, 184-192.
http://dx.doi.org/10.1542/peds.2011-2947
[53] Jun, J.Y., Lee, Y.-J.G., Lee, S.-H., Yoo, S.Y., Song, J. and Kim, S.J. (2015) Association between Defense Mechanisms
and Psychiatric Symptoms in North Korean Refugees. Comprehensive Psychiatry, 56, 179-187.
http://dx.doi.org/10.1016/j.comppsych.2014.10.001