The Neuropsychology and Neurology of Sexual
Deviance: A Review and Pilot Study
Christian C. Joyal & Deborah N. Black &
Published online: 2 June 2007
# Springer Science + Business Media, LLC 2007
Abstract Current neurological hypotheses of paraphilia posit that sexual deviance is
associated with frontal and/or temporal lobe damage. This broad conception is based
on few investigations, however, and the first goal of this study was to review the
existing data derived from neuropsychiatry, neuroimaging and neuropsychology. It is
concluded that although fronto-temporal dysfunctions are sporadically reported
among sexual offenders, the evidence is scarce and it might not be specific to this
type of offending. The second objective of this investigation was to gather
preliminary neuropsychological data with more homogeneous subgroups of sexual
offenders. A profile of lower-order executive dysfunctions (e.g. sustained attention
and inhibition) and verbal deficits with intact or good capacities for higher-order
executive functioning (e.g. reasoning and cognitive flexibility) and visuo-spatial
processing was preferentially found among sexual offenders, suggesting basal
fronto-temporal anomalies. Importantly, pedophiles were more consistently and
severely impaired than rapists of adults. However, this basal fronto-temporal profile
is not characteristic of sexual deviance, as it is also found in association with
delinquency and criminality in general. Future neuropsychological and brain
imaging studies should consider subgroups of sexual offenders and recruit non-
sexual violent persons and non-violent individuals in order to disentangle the
complex relations between brain anomalies and sexual deviance.
Sex Abuse (2007) 19:155–173
C. C. Joyal:D. N. Black:B. Dassylva
Institut Philippe-Pinel de Montréal, 10905 Henri-Bourassa Bld, Montreal, QC H1C 1H1, Canada
C. C. Joyal (*)
Psychology Department, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
In his classic book Psychopathia Sexualis, Krafft-Ebing (1886/1965) introduced the
concept of sexual anomalies by stating that they represent “the signs of an inherited
diseased condition of the central nervous system” (p.61). Although the quest for a
pathognomonic or putative brain abnormality of deviant or variant sexuality has
proven futile, the role of neurological factors and peculiar neuropsychological
functioning are being integrated in theories of sexual offending (e.g. Ward and
Beech 2006). Still, the number of neuropsychological studies concerned with sexual
offenders is surprisingly low and the results are highly divergent. While pedophilia
and other deviant sexual activities are traditionally associated with left hemisphere
anomalies (involving particularly frontal-temporal circuits e.g. Flor-Henry 1987;
Yeudall & Fromm-Auch 1979; see Lang 1993 for a review of these earlier studies),
recent results are rather mixed. Available data concerning the links between brain
anomalies and deviant sexuality were obtained with four main approaches: (1)
neuropsychiatry, the study of acquired psychiatric disorders following brain damage;
(2) structural neuroimaging; (3) neuropsychological assessments and; (4) functional
neuroimaging of sexual offenders compared with nonsexual offenders and the
general population. These reports are reviewed and summarized below.
Neuropsychiatry of Sexual Deviance
Both cortical and subcortical structures are important for normal sexual functioning,
especially in the anterior parts of the brain. While the frontal and temporal cortices
are believed to be involved in the modulation of drive, initiation, and sexual
activation, subcortical structures including the hippocampus, the amygdala, the
septal complex and the hypothalamus are implicated in the modulation of sexual
behaviors and genital responses (e.g. Zasler 1994). Neuroimaging studies confirmed
the involvement of frontal, temporal, cingulate and subcortical structures in the
regulation of sexual arousal (e.g. Redouté et al. 2000; Arnow et al. 2002). Damage
or anomalies to one of these neural nodes are hypothesized to be involved in sexual
deviance, including hypersexuality. The first type of evidence derived from persons
who display deviant sexual behaviors following an acute brain injury or in
conjunction with a degenerative disease.
Following a brain injury, the most common complaint about sexuality is, by far, a
reduction, not an increase of the drive (e.g. Toone et al. 1989; Zasler 1994). Still,
brain damage might also provoke hypersexuality and paraphilia. Few early, well-
known cases of sexual deviations were reported in association with temporal lobe
seizures; they typically involved fetishism or transvestism (Mitchell et al. 1954;
Davies and Morgenstern 1960; Epstein 1961; Hunter et al. 1963; Walinder 1965;
Kolarsky et al. 1967; Hoenig and Kenna 1979). Vascular lesions affecting the
temporal lobes (Monga et al. 1986) and damage of the anterior temporal lobes
inducing the human Klüver–Bucy syndrome might also lead to deviant sexual
behavior and hypersexuality (e.g. Marlowe et al. 1975; Ghika-Schmid et al. 1995).
Hypersexuality and paraphilias have also been observed in conjunction with damage
to subcortical structures such as the thalamus or hypothalamus (Cummings and
Mendez 1984; Miller et al. 1986; Absher et al. 2000), the septum (Miller et al. 1986;
156 Sex Abuse (2007) 19:155–173
Gorman and Cummings 1992), the hippocampus, (Mendez et al. 2000; Casanova
et al. 2002), and the basal ganglia (globus pallidus; Mendez et al. 2004; striatum in
Huntington disease; e.g. Dewhurst et al. 1970). These reports commonly lead to the
conclusion that sexual deviance is associated with anomalies of a vast cortico-
subcortical, fronto-temporal circuit (e.g. Lang 1993 for a review). As aforemen-
tioned however, this conclusion lacks of specificity. First, generalized behavioral
impulsivity might also emerge after damage to basal frontal-subcortical circuits (e.g.
Mega and Cummings 1994; Starkstein and Kremer 2001) and, in turn, hypersex-
uality could simply represent one of many manifestations of a more generalized
impulsivity syndrome. Second, non-sexual violence is also classically associated
with fronto-temporal-limbic damage or dysfunction, especially in the left hemisphere
(e.g. see Raine and Buchsbaum 1996; Volavka 2002 for reviews). Thus, impulsivity
and/or violence might be more closely associated with fronto-temporal anomalies
than sexual deviance per se.
In view of these observations, it could prove useful to separately consider the role
played by the frontal and the temporal lobes, both in non-violent deviant sexuality
and non-sexual violence. After reviewing six cases, Miller et al. (1986) suggested
that basal frontal and/or diencephalic lesions are more likely to provoke
hypersexuality whereas temporo-limbic damages are more closely associated with
true modification of sexual preferences. Stein et al. (2000b) further concluded that
frontal lesions would provoke general disinhibition, including impulsive hypersexual
symptoms, with temporo-limbic damages possibly leading to disturbances in sexual
appetite itself, including change in the direction of sexual drive, and striatal lesions
increasing the triggering of sexual response in a compulsive pattern. Thus,
heightened sexual activity might be more closely associated with frontal damage
(especially basal; e.g. Lesniak et al. 1972), while modifications of sexual preference
would more likely result from temporal lobe lesions (e.g. Cummings 1985; Langevin
et al. 1985; Miller et al. 1986). The opposite pattern has been observed, however (i.e.
hypersexuality in conjunction with temporal lobe anomalies, e.g. Blumer 1970, and
modification of sexual preference after basal frontal damage, e.g. Burns and
Swerdlow 2003), so that future paradigms should distinguish between genuine
changes of sexual orientation and mere deficits of global behavioral inhibition that
include sexually oriented impulsivity. Certainly, instances of true paraphilias
following a brain injury are extremely rare and they are usually accompanied by
several manifestations of a broader disinhibition deficit such as aggressiveness,
talkativeness, bad judgment, low social abilities and/or hyperphagia (e.g. Mendez
et al. 2000). For instance, in a well-known report of four men who apparently
acquired pedophilia in line with cognitive deterioration, other signs of impulsivity
and hypersexuality were observed, including marked increases in sexual demands to
their wives, new extra-marital affairs with female adults, and explosive violence
(Regestein and Reich 1978; see also examples of apparent late-onset, acquired
paraphilias that seem to be manifestations of a wider, more generalized inhibition
control deficit associated with multiple sceloris; Huws et al. 1991; Ortego et al.
1993; Frohman et al. 2002).
In brief, brain damage rarely induces genuine deviance limited to sexual behavior.
Insult to one or more nodes of a neural circuitry comprising the basal frontal cortex,
the basal temporal lobe, the diencephalic structures and the limbic components,
Sex Abuse (2007) 19:155–173 157
including the septum, more commonly provoke behavioral disinhibition, a marked
elevation of sexual urges, and a decrease of mate selectivity. However, the possible
link between temporal lobe dysfunction and aberrant sexual behaviors is still
intriguing and deserves further investigation.
Structural Neurology of Sexual Offenders
Structural brain imaging techniques offer another avenue to investigate the link
between neurology and sexual deviance. Such studies are still unusual however, and
most of them were pioneered investigations performed by the group of Ron
Langevin with computerized tomography (CT). Overall, these precursory reports
tended to emphasize the link between sexual deviance and temporal lobe anomalies,
although the conclusions are tentative and replications with recent imaging
techniques and improved approaches for volumetric measurement are warranted.
First, a dilatation of the temporal horn of the lateral ventricle, especially in the right
hemisphere, has been found in sadistic offenders compared with nonsadistic sexual
and nonsexual offenders (Langevin et al. 1985; Hucker et al. 1988; Langevin et al.
1988a). Intriguingly however, these sadistic sexual offenders were significantly
better in neuropsychological testing than the nonsadistic sexual offenders (Hucker
et al. 1988), rendering the interpretation difficult. Moreover, the ventricular
anomalies reported in these studies were based on a very limited number of
individuals (between 3 and 9 persons), who might overlap between studies (e.g. all
the participants in the study of Langevin et al. 1985 were included in Hucker et al.
1988). The ventricular dilatation was also subjectively or qualitatively determined
and it seems to be based on a series of uncorrected t-tests. Other brain anomalies
might also have been overlooked by the low resolution of the scanner and the small
number of images analyzed (e.g. a single slice of 10 mm). The same group of
researchers subsequently used quantitative analyses to measure different brain areas
in pedophiles, incest offenders, aggressive sexual assaulters and nonviolent
nonsexual offenders to find smaller left frontal and temporal areas in sexual
offenders, as hypothesized (Wright et al. 1990). Left hemispheric asymmetry
(smaller left than right hemisphere) was also observed, exclusively among the
pedophiles. However, it seems that neither the height nor the head size of the
participants were considered as covariates, which might induce an important artifact.
Hucker et al. (1986) also reported that left and/or right dilatation of the temporal or
anterior horns was more frequently observed in 29 pedophiles than 14 nonsexual
nonviolent offenders, although two subsequent investigations from the same
laboratory failed to confirm these results (Langevin et al. 1988b, 1989a). Still,
approximately 25% of the child abusers were judged as suffering from temporal lobe
anomalies, usually a dilatation of the temporal horn, reflecting the importance of
including a comparison group of non offenders in this type of investigation.
Overall, there is a possible association between temporal lobe anomaly and sexual
offenses, although it is weakly established at best. Clearly, there is no pathogno-
monic sign for sexual deviance. The main brain anomalies reported with CT is an
enlargement of the temporal ventricle, interpreted as a consequence of cortical tissue
reduction (Hucker et al. 1988; Langevin et al. 1988b). No such difference emerged
between homicide offenders or aggressive assaulters and property offenders however
158 Sex Abuse (2007) 19:155–173
(Langevin et al. 1987), nor between pedophiles, incestuous offenders and sexually
aggressive persons (Wright et al. 1990). The sole imaging study concerned with non-
contact sexual offences (exhibitionism) generated negative results (Langevin et al.
1989b). Exhibitionism might be associated with compulsion (e.g. Stein et al. 2000a)
and, as such, with subcortical structures anomalies, difficult to detect with CT
neostriatum). Future volumetric studies should use MRI scanning and objective,
standardized morphometric assessments, as well as oppose subgroups of sexual
offenders, not only to non-sexual offenders but also to non-offenders.
The Neuropsychology of Sexual Offenders
The neuropsychological evaluation of sexual offenders represents the most common
source of information about the links between brain anomalies and sexual offense/
deviance. Deficits in tasks sensitive to frontal and/or temporal lobe lesions,
especially to the left hemisphere, are the most common finding. However, the
typical neuropsychological includes diverse types of sexual offenders (e.g.
exhibitionists, pedophiles and rapists of adults) and compares them, as a
homogeneous group, to non-sexual offenders or non-criminals, which lead to highly
In the eighties, Flor-Henry (1987) authored an influential book chapter about the
neuropsychology of sexual deviance. Based on unpublished data collected by
Yeudall and colleagues with 109 sexual offenders (including homicidal rapists,
aggressive sexual criminals, pedophiles and incest offenders, fetishists, and
exhibitionists) and 192 non-criminal controls, Flor-Henry (1987) concluded that
verbal abilities and executive functions were the most impaired cognitive domains of
sexual offenders. Based on these results and corroborative EEG data, Flor-Henry
(1987) proposed the seminal hypothesis that sexual deviance is associated with a
dysfunctional cerebral asymmetry, involving fronto-temporal anomalies of the left
hemisphere (see Lang 1993).
Subsequent neuropsychological studies involving sexual offenders generated
mixed results (e.g. Galski et al. 1990; Gillespie and McKenzie 2000; Hucker et al.
1988; Langevin et al. 1989a; O’Carroll 1989; Stone and Thompson 2001; Dolan
et al. 2002; Kelly et al. 2002), although several methodological limitations were
present. Among these were the inclusion of different subgroups of sexual offenders;
the absence of comparison with persons representing the general population
(comparing exclusively with non-sexual offenders elevates the risk of false negative
results); the lack of consideration for socio-cultural backgrounds or demographic
factors such as education and I.Q. levels; the presence of multiple bivariate
comparisons uncorrected for repetition (series of uncorrected t-tests); and the use of
older neuropsychological batteries with uncertain psychometric properties (e.g. the
Luria–Nebraska battery). Still, interesting results emerged from these studies, which
usually tend to concur with the left fronto-temporal dysfunction hypothesis of Flor-
For instance, Gillespie and McKenzie (2000) reported that sexual offenders, as a
group (different subtypes were included), obtained lower scores than nonsexual
offenders on measures of verbal abilities (e.g. vocabulary, similarities, verbal
fluency, verbal learning), while both groups obtained similar results on tests known
Sex Abuse (2007) 19:155–173159
to be sensitive to right hemisphere lesions (e.g. design learning, line orientation,
facial recognition). However, the differences were not statistically significant, which
might reflect the absence of a comparison group from the general population.
Similarly, Dolan et al. (2002) used neuropsychological tasks known to evaluate
fronto-temporal functioning (the Stroop test, verbal fluency, the Trail Making B, and
the Weschler Memory Scale) and found no difference between homicide offenders,
sexual offenders, and arson offenders when controlling for age, years of education
and IQ. Again, these negative results might either reflect the absence of comparisons
with a group of non-offenders or the absence of difference between sexual and non-
sexual offenders. Kelly et al. (2002) used an extensive neuropsychological battery to
compare 30 male adolescent sex offenders (including incest offenders, extra-familial
pedophiles, and rapists of adults or adolescents) with 20 male adolescents living in
an under-privileged neighborhood. Sexual offenders showed significant impairment
in working memory, lower-order executive functioning (sustained attention and
inhibition), and fluency (verbal and non-verbal), comforting the fronto-temporal
anomaly hypothesis. Interestingly, no deficits in higher executive functions (i.e.
planning, organization, modifying an ongoing behavior according to feedback) were
found in sexual offenders as measured with the Wisconsin Card Sorting task and the
Tower of London.
Overall, previous neuropsychological reports tentatively supported the notion of
frontal and/or temporal dysfunctions among sexual offenders. The possibility
remains, however, that this profile characterizes offenders in general, not only
sexual offenders. Behavioral impulsivity, for instance, closely linked with basal
frontal damage (e.g. Stuss and Knight 2002), might underlie violent sexual
aggression, nonviolent sexual compulsions (e.g. exhibitionism), and non-violent,
non-sexual criminal acts (e.g. Galski et al. 1990). Future large-scale studies should
recruit both sexual and non sexual offenders and non offenders. Another important
avenue to investigate is the type of modus operandis among sexual offenders, as
different subgroups might present different neuropsychological profiles, which is
stressed by a growing number of authors (e.g. Cantor et al. 2005; Kelly et al. 2002).
For instance, it is intuitively conceivable that impulsive intra-familial pedophilia
would be associated with a distinct cognitive profile than that linked with well-
planned sadistic sequestrations of chosen adult targets. Two main factors associated
with the modus operandis that might better characterize subgroups of sexual
offenders are the contact versus non-contact type of offense and the age (or mean
age) of the victim(s). Little neuropsychological evidence is available concerning
these factors; it is described below.
Contact vs. Non-contact Type of Sexual Offense
The physical contact/non-contact distinction might be clinically significant, at least
from the neuropsychological perspective. It seems for instance that exhibitionists,
contrarily to pedophiles, present brain CT scans, Full Scale Intellectual Quotient
(FSIQ), Verbal IQ (VIQ), Performance IQ (PIQ), and overall neuropsychological
capacities comparable to those of non-sexual, property offenders (Langevin et al.
1989b). Galski et al. (1990) also stressed that among 35 sexual offenders who took
part in their study, those who assaulted (interpersonal offence) obtained significantly
160 Sex Abuse (2007) 19:155–173
lower scores at the Luria–Nebraska scales of left hemisphere, left sensorimotor,
expressive speech, and pathognomonic signs than those who did not assault (mostly
exhibitionists). Item analysis of these scales strongly implicated the left hemisphere
as an area of specific dysfunction and the authors concluded that assaultive sexual
offenses were associated with more severe neuropsychological anomalies, which
would be specifically linked with left hemisphere functioning, than non-assaultive
offenders (Galski et al. 1990). Thus, separating sexual offenders who assault (or
make contact) from those who do not (e.g. exhibitionists, voyeurs, certain fetishists)
might prove worthwhile for future neuropsychological investigations. Factors related
with the victims might also discriminate between meaningful subgroups, especially
the preferred age.
Considering the Age of the Victim(s)
A growing number of neuropsychological and neuroimaging reports suggest that
pedophiles, as a group, are more cognitively impaired than rapists of adults
(Blanchard et al. 1999; Cantor et al. 2005; Graber et al. 1982; Hucker et al. 1986;
Langevin et al. 1988b; Martin 1999; Scott et al. 1984). Certain precursory data
indicate lower regional cerebral blood flow (rCBF) in pedophiles than in rapists of
adults (see the next section; Graber et al. 1982), which might affect more specifically
the anterior part of the brain (Hendricks et al. 1988). Scott et al. (1984) found that 14
pedophiles obtained worse results on all scales of the Luria–Nebraska battery than
rapists of adults and Wright et al. (1990) reported left interhemispheric asymmetry in
pedophiles but not in rapists of adults or property/fraud offenders. More recently,
Martin (1999) found pedophiles to be more cognitively impaired than rapists of
adults among 35 sexual offenders, especially in the attention-memory domain,
comforting the broad hypothesis of a fronto-temporal dysfunction. Blanchard et al.
(1999) reported that, among 991 sexual offenders, pedophiles obtained significantly
lower estimates of intelligence than sexual offenders of adults, and a recent meta-
analysis elegantly confirmed this intuitive notion that the I.Q. of sexual offenders is
significantly correlated with the age of their victims (Cantor et al. 2005). Thus,
future neurobehavioral studies concerned with sexual offenders should separately
consider those whose prefer children from those who assaulted adults.
Interestingly, certain non-verbal functions (which depend more crucially on right
hemispheric integrity) might be normal or within average among sexual offenders,
including pedophiles. In a refinement of his theory, Flor-Henry et al. (1991) focused
exclusively on pedophiles (N=96) and reported abnormal cortical activation during
verbal but not spatial processing compared with true controls. This effect was more
pronounced among participants who preferred sexual partners aged between 6 and
12 years. Thus, the visuo-spatial domain might not be as affected as the verbal
processing capacities among pedophiles. In line with this possibility, Hucker et al.
(1986) concluded that a group of 39 male outpatient pedophiles suffered more
commonly from left than right hemisphere anomalies as indicated by the Halstead–
Reitan battery, the Luria–Nebraska battery, and CT scans compared with property
offenders. The same research group subsequently reported that incest offenders (n=
88) obtained significantly lower I.Q. scores than property offenders and the
neuropsychological profiles seemed to indicate verbal deficits and apparent left-
Sex Abuse (2007) 19:155–173 161
hemispheric dysfunction. (Langevin et al. 1988b). These authors also reported that
brain area measurements performed on a single CT slice suggested significantly
smaller left hemispheres, specifically at the frontal and left temporal levels in the
group of sex offenders relatively to nonsexual nonviolent (property) offenders
(Wright et al. 1990). Finally, an intriguing, high incidence of non-right
handedness, which might indicate left-hemispheric impairment in clinical
groups, has been reported among pedophiles (Bogaert 2001; Cantor et al.
2004). Thus, some indications of left anterior hemisphere (fronto-temporal)
anomalies are found among sexual offenders, which might affect pedophiles more
Functional Neurology of Sexual Offenders
Functional brain imaging of abnormal or variant sexuality is still in its infancy and
very few studies are currently available. It is first interesting to note that presentation
of sexually arousing stimuli induces a lowering of orbitofrontal blood flow in men
with normal libido (reducing inhibition), while the same part of the brain maintains
its activation in men with hypoactive sexual desire (keeping constant higher levels of
inhibition; Stoleru et al. 2003). This orbital, inferior part of the frontal lobe is
well known for its crucial role in behavioral and social inhibition (e.g. Bechara
et al. 2000), and might also be involved in the regulation of sexual drive and its
direction. As abovementioned, acquired pedophilia commonly represents one of
several aspects of a general impulsivity disorder (see the neuropsychiatry section),
which is likely to involve inferior frontal anomalies. Beside, older brain imaging
studies tended to report more impairment in pedophiles than rapists of adults, as
Graber et al. (1982) reported low regional cerebral blood flow (rCBF) in 3
pedophiles but not in 3 rapists compared with normative data. These researchers
subsequently extended their results with 16 child molesters who displayed lower
rCBF values than normal controls, especially within the anterior part of the brain
(Hendricks et al. 1988). Although the control group in this study included
professional and university staff employees, rendering difficult the interpretation
of the data, the opposition between pedophiles and rapists of adult deserves
further attention. Temporal lobe hypometabolism has also been associated with
marked increases in sexual drive, including recent interest for extra-familial
children, in two patients suffering from either frontotemporal dementia or
hippocampal sclerosis (Mendez et al. 2000). However, each of these patients
presented numerous other impulsive behaviors and both had a history of incest that
antedated the neurological conditions. Thus, damage to both frontal and temporal
regions (or to fibers connecting them) is likely to have affected these patients.
At the present time, investigations using recent techniques such as fMRI,
recruiting sufficient numbers of sexual offenders and considering more
homogenous subgroups are clearly needed.
Overall, while neuropsychological and neuroimaging data concerning sexual
offenders are limited and tainted with numerous methodological limits, the most
frequent finding involves verbal deficits and other manifestations of left fronto-
temporal anomalies. Thus, the hypothesis that a left fronto-temporal abnormality
would disrupt a regulatory control mechanism and provoke paraphilic tendencies
162 Sex Abuse (2007) 19:155–173
still prevails (e.g. Lang 1993; Waismann et al. 2003). In order to explore the
possibility that fronto-temporal and not parieto-occipital dysfunctions would affect
sexual offenders; that more indications of left than right hemisphere damage
would be observed; and that pedophiles would be more cognitively impaired
than rapists of adults, preliminary data were collected among 20 male inpatient
sexual offenders. A series of neuropsychological tests were specifically selected
and norms matched for I.Q. level, number of years of education, age and
gender were used as comparison. This investigation was conducted to collect
pilot data, which are presented below.
Pilot Neuropsychological Assessments: Methods
Participants for this pilot study were referred from regional penitentiaries to be
part of a special treatment program for illegal or disturbing sexual behavior in a
forensic psychiatric hospital. Twenty-five consecutively admitted male patients
were approached by the psychiatrist in charge of the program and asked to
participate in the present investigation. Twenty agreed and met the criteria of
inclusion: being an adult male and having sexually assaulted at least two
different persons. They were all male Caucasian French-canadians with a mean
age of 45.1±8.7 and educational level of 8.1±2.9 years. The victims were
extra-familial, all participants were recidivists and they all admitted their
offences. All adult victims were females and 50% (n=16) of the children victims
were girls. Neuropsychological results of these sexual offenders were compared
with normative data because the goal of this preliminary study was to pinpoint any
significant difference between profile of sexual offenders and the general
population with similar age and education attainment and also because of the
growing number of available data sets that segregate for age, gender, years of
education and IQ (Mitrushina et al. 2005; Spreen and Straus 1998). Comparisons
with non-sexual offenders or delinquents were discarded because it was not the
purpose of this pilot investigation and also because of the numerous, possibly
false, negative results they already generated (see Raine 1993 for a critique). All
sexual offenders were evaluated with the Weschler Adult Intelligence Scales-III
(WAIS-III) and a series of classic neuropsychological tasks. The WAIS-III served
mainly to compare the Full Scale Intelligence Quotients (FSIQ) of study groups
and oppose the Verbal Intelligence Quotient (VIQ) to the Performance Intelligence
Quotient (PIQ) within each group. The neuropsychological tasks are either
sensitive to fronto-temporal anomalies (the Stroop; the Controlled Oral Word
Association Task [COWAT]; the California Verbal Learning Test [CVLT]; the
Wisconsin Card Sorting Task [WCST]; and the Trail Making B) or posterior
damage (the Rey–Osterrieth Complex Figure [ROCF] for visuo-spatial integra-
tion). Comprehensive descriptions, origins, and clinical significance of the
neuropsychological tasks are available elsewhere (e.g. Lezak et al. 2004).
Comparisons between the groups were assessed with t-tests because the size of the
study groups prevents using multivariate analyses. As such, the alpha was set at
0.001 to partially control for type I errors (with a maximum of 60 degrees of
Sex Abuse (2007) 19:155–173163
freedom with normative samples), although false positive results are preferable to
type II errors with pilot data.
The results are summarized in Table 1. Assessments of intellectual quotient
confirmed that sexual offenders (mean of 86) present lower FSIQ on average than
the general population. Interestingly, rapists of adults scored higher (mean of 89.4,
approaching the 50th percentile of the general population with 8 years of formal
education; Ryan et al. 1991) than pedophiles (mean of 82.9 for the 25th percentile).
While not clinically significant (less than one standard deviation), this difference is
moderate in size according to the standards of Cohen (0.55; Cohen 1992). Also
worth noting is the fact that in both groups the VIQ was lower than the PIQ and the
better performance in the WAIS-IV was attained in the Block Design task (mean
scale score of 9.50, not shown).
During the Stroop task, while sexual offenders, as a group, obtained results
statistically comparable with norms to complete condition A (word reading; 52.8±
15.8 s vs. 45.1±9.0 s; t (60)=1.94; p>0.1; no significant difference between
pedophiles and rapists of adults; t (18)=1.78, p>0.1), they needed significantly more
time to complete conditions B (color naming; 77.2±19.8 s vs. 59.4±10.4; t (60)=
3.91; p<0.001) and C (interference; 135.6±35.6 s vs. 108.7±23.7; t (60)=3.69; p<
0.001). However, these differences remained significant only for the pedophile
group (color naming, 85.3±20.1, t (60)=4.29, p<0.001 and interference, 144.4±
37.1, t (60)=3.57, p<0.001; Table 1), not rapists of adults (color naming, 65.1±
10.2, t (60)=1.35, p>0.1; interference, 120.6±29.2, t (60)=1.40, p>0.1; Table 1).
The total number of interference errors was also significantly higher for pedophiles
(t (60)=8.59; p<0.001) but not rapists of adults (t (60)=1.75, p>0.1) compared
with the norms (Table 1). Thus, no significant difference emerged between
normative data and the rapists of adults for any Stroop condition.
As for verbal fluency (COWAT), sexual offenders produced on average
significantly less words beginning with the letter P (11.5±4.2 vs.17.3±5.5; t (46)=
−4.14, p<0.001) and less names of animals (15.7±5.2 vs. 29.4±7.8; t (46)=−7.32, p<
0.001) than men from the general population aged between 30 and 45 with less than 9
years of education. These deficits affected both subgroups of offenders (letter P:
pedophiles, 11.6±4.9, t (38)=−3.26, p=0.001; rapists of adults, 11.4±3.1, t (34)=
−3.91; p<0.001; names of animals: pedophiles, 16.2±2, t (38)=−8.35, p<0.001;
rapists of adults, 15±2.1, t (34)=−8.73, p<0.001 vs. associated norms, see Table 1).
No significant difference emerged between the subgroups of offenders (letter P, t (18)=
0.21, p>0.1; names of animals, t (18)=0.58, p>0.1). During the CVLT, sexual
offenders recalled on average 41.85±8.7 words in total after the five learning trials,
which was significantly lower than production from persons among the general
population with an IQ ranging from 80 to 99 and aged between 30 and 39 years
(Wiens et al. 1994; 53.5±8.3; t (60)=−5.20; p<0.001). This difference was significant
for both study groups (pedophiles, 39.3±7.3; t (60)=−5.94; p<0.001 and rapists of
adults, 45.6±9.7; t (60)=−3.61, p<0.001; Table 1). The performance of pedophiles
tended to be lower than that of rapists (t=1.66, p=0.12). During the delayed free
164 Sex Abuse (2007) 19:155–173
recall, sexual offenders produced on average 9.1±3.3 correct words compared with
10.95±2.7 for the norms, which is not significant according to our corrected
criteria for multiple comparisons (t (60)=−2.28, p<0.05). Pedophiles also tended to
recall fewer words than rapists of adults and controls (mean of 8.17±2.7 vs. 10.5±3.8,
t (60)=−2.78, p<0.01 and 10.95±2.5, t (60)=−3.27, p<0.01, respectively).
As for the card sorting task (WCST), sex offenders completed 4.7 categories and
committed 16.9 perseverative errors on average, which represent better results
than those reported by Stratta et al. (1993) among the general population with
less than 9 years of education (3.0 categories achieved and 26 perseverative er-
rors), although the differences did not reach our statistical criteria of 0.001 (t (28)=
3.03, p<0.01 and t=2.63, p<0.02, respectively). In the same vein, sexual offenders
offered a performance similar to that of persons with an average of 14.5 years of
education and a mean FSIQ of 114.5 (Boone et al. 1993; categories achieved : 4.6±
1.9 vs. 4.7±1.3, t (58)=0.02, respectively p>0.1; and 19.8±16.8 vs. 16.9±8.5
perseverative errors, t (58)=0.87, p>0.1, Table 1). Compared with the original
normative data for the WCST (Heaton et al. 1993; persons from the general
population aged between 40 and 49 with less than 9 years of education), sex
offenders ranked reasonably well at the 61st percentile. There was no difference
between subgroups for the mean numbers of categories completed (pedophiles,
4.67±1.2 vs. rapists, 4.75±1.6, t (18)=0.23, p>0.1) and perseverative errors
(pedophiles, 15.3±8.4 vs. rapists, 19.4±8.6; t (18)=1.06, p>0.1, Table 1).
As depicted in Table 1, mean time to complete the Trail Making B was
comparable between sexual offenders and healthy male Canadians aged between
40 and 59 with less than a high-school level completion (Bornstein 1985), healthy
controls with fewer than 12 years of education (Heaton et al. 1986), and
hospitalized non-brain injured Canadian patients aged between 40 and 49 with
an average FSIQ of 105 (Goul and Brown 1970). No significant difference
emerged between pedophiles and rapists of adults (t (18)=0.38; p>0.1). Sexual
offenders committed on average more shifting errors (1.4) than male adults
from the general population (0.5; Ruffolo, Guilmette, & Willis 2000), although
the difference was not significant according to our adjusted criterion (t (60)=2.61,
p<0.02). While this measure might be viewed as an indication of behavioral
impulsivity, it is rarely provided in published norms. As for motor speed, sexual
offenders offered average performance when compared with the norms of the D-
KEFS for persons aged between 40 and 49 (between 30 and 35 s correspond to a
scaled score of 10; Delis et al. 2001).
Finally, according to normative data provided by Spreen and Strauss (1998)
for the ROCF, the mean copy score of sexual offenders (31.5±3.2) did not differ
significantly from that of well-educated (14 years) persons from the general
population aged between 30 and 49 (32.0±2.9; t (56)=0.64, p>0.1; see Table 1).
Compared with other younger healthy participants who received a higher number
of years of education, sexual offenders also obtained a comparable mean score
for the copy of the figure (Table 1). As for the recall, few normative data are
available with a 30 min delay, although no significant difference emerged between
sexual offenders (17.4±6.5) and the performances observed by Spreen and Strauss
(1998; t (56)=0.15; p>0.1, see Table 1). They were no difference between the
pedophiles and rapists of adults in either the copy or the recall of the figure.
Sex Abuse (2007) 19:155–173165
Table 1 Results in neuropsychological tasks by pedophiles (N=12) and rapists of female adults (N=8) compared with normative data (mean±standard deviation)
Intellectual Quotient (I.Q.)
Rapists of adults
Non verbal IQ
A—Word reading (s)
B—Color naming (s)
115.2 ± 29.2
Total words recalled
Delayed free recall
166Sex Abuse (2007) 19:155–173
Intellectual Quotient (I.Q.)
Rapists of adults
Trail Making B
Shifting time (s)
Motor speed time (s)
30 to 35m
Delayed recall (30 min)
CVLT California Verbal Learning Task, WCST Wisconsin Card Sorting Task, ROCF Rey–Osterrieth Complexe Figure, N/A Not Available or Applicable, s seconds.
*p<0.001 or lower compared with the average of normsb, c, d
**p<0.001 or lower compared with the associated norms
***p<0.01 compared with the associated norms (not considered as significant)
aMedium effect size of 0.55, Cohen (1992)
bD’Elia et al.(unpublished, in Mitrushina et al. 2005); 118 ♂ aged between 40 & 59; <16 years of education
cDemick and Harkins 1997 (in Mitrushina et al. 2005); 55 ♀ ♂; aged between 40 & 59; unknown education attainment
dMiller 2003 (in Mitrushina et al. 2005); 73 ♂; aged between 35 and 44; <16 years of education
eCardebat et al. (1990); ♂ only, aged between 30 & 45 with <9 years of education
fWiens et al. (1994); ♂ only, aged between 30 and 39 with an IQ ranging from 80 and 99
gStratta et al. (1993); ♀ ♂ with less than 9 years of education
hBoone et al. (1993); ♀ ♂ aged between 45 and 49
iRuffolo et al. 2000; ♀ ♂, mean age of 29 and 14 years of education on average.
jHeaton et al. 1986; healthy ♀ ♂, <12 years of education. Standard deviations not provided.
kBornstein 1985; healthy Canadian ♂ aged between 40 and 59, < high-school level
lGoul and Brown 1970; hospitalized non-neurological ♀ ♂ patients aged between 40–49.
mD-KEFS norms: ♀ ♂, raw scores for the 40–49 age group corresponding to a scale score of 10 (average of the sample).
nSpreen and Strauss 1998; ♀ ♂, healthy controls aged between 30 and 49 years with a mean of 14.1 years of education.
oKing 1981; ♀ ♂ Healthy volunteers and non-psychiatric or non-neurological patients; mean age=39.6 years; mean number of years of education=11.4; mean IQ=104.5.
pHartmann and Potter 1998; ♀ ♂ students, mean age=22.3; mean number of years of education=15.3
qSchreiber et al. 1999; ♀ ♂, mean age=29.5±11.5 years; mean number of years of education: 15.1 ( 1.7)
Sex Abuse (2007) 19:155–173 167
Four main conclusions emerged from this review of the literature. First, evidence of
a neuropsychological profile characterizing sexual offenders is limited at best and
based on few studies. Second, when neuropsychological deficits are observed, they
tend to indicate fronto-temporal anomalies (perhaps more particularly in the left
hemisphere), especially at the inferior, basal level. Third, the opposition between
lower-order executive function (e.g. impulsivity) and higher-order executive function
(e.g. cognitive flexibility) has been overlooked and deficits of the former system
might play a more important role than deficits of the latter in many deviant sexual
behaviors. Finally and importantly, it seems crucial to consider more homogeneous
subgroups of sexual offenders, as different types of offenses might be associated
with different types of impairments and severity.
The present pilot data, obtained with a highly limited number of participants, tend
to indicate deficits in verbal skills (verbal processing and verbal memory), response
inhibition, and sustained attention among sexual offenders, with average or good
capacities for set shifting, cognitive flexibility, and visuo-spatial integration. This
profile corroborates the notion that anterior cerebral anomalies (fronto-temporal) are
more likely to be found than posterior malfunction (parieto-occipital; e.g. relatively
good performance at the Rey figure and the Block design subtests) in sexual
offenders, perhaps affecting more particularly the left hemisphere (VIQ<PIQ, CVLT,
see also Flor-Henry 1987). More interestingly, it further suggests that basal, inferior
fronto-temporal circuits might be more closely involved than dorsal, superior
Lower executive functions such as behavioral inhibition and sustained attention
depend upon inferior and medial frontal areas while higher executive functions such
as cognitive flexibility, logical deduction, and working memory depend more
crucially upon dorsal and lateral frontal areas (e.g. Lezak et al. 2004). Average or
good capacities at the WCST are commonly observed among sexual offenders when
socio-demographic factors are controlled (this and several other preliminary studies;
Cohen et al. 2002; Dolan et al. 2002; Kelly et al. 2002; Martin 1999; Miller 1998;
Rubenstein 1992). The WCST is a well-known measure of higher-order executive
functions (e.g. cognitive flexibility and simple problem solving), sensitive to
superior, dorsal frontal cortex damage (e.g. Milner 1963). Certain paraphilias (e.g.
exhibitionism) could also be seen as a type of compulsive or impulsive behavior
(e.g. Stein et al. 2000b), which would be closely related with basal or medial frontal
anomalies. Future large-scale neuropsychological studies involving sexual offenders
would thus benefit from including specific types of sexual behaviors and impulsivity
measures, such as the Go/no-go, the stop signal task or the CPT-II.
Using higher-order executive functions such as planning capacities (e.g. Tower of
London), problem solving (e.g. the Category Task) and working memory (e.g. Digit
Backward; sensitive to superior frontal damage) as covariates would also help
determining the relative impact of lower-order executive dysfunctions on higher-
order executive functions. It is worth noting for instance that abilities for problem
solving and verbal processing might be significantly (and inversely) correlated with
behavioral impulsivity among sexual offenders (Martin 1999). It is thus plausible
that basic impairments of inhibition, attention, and language processing represent the
168Sex Abuse (2007) 19:155–173
true causes of abnormal higher-order executive functions occasionally observed
among sexual offenders (Martin 1999; see also Block 1995 and Barkley 1997 for
similar propositions with juvenile delinquents and children with ADHD, respective-
ly). It could be hypothesized that performance at the WCST and other measures of
higher executive functions (especially planning and working memory) will improve
significantly after controlling for the effect of impulsivity. If confirmed, this
neuropsychological profile would help focusing the treatment plans on more basic
behavioral deficits such as impulsivity.
This and several other reports referred to fronto-temporal anomalies among
sexual offenders, although these indications are common in clinical neuropsychol-
ogy. As such, the distinction between frontal and temporal damage would deserves
further clarification. During the last quarter of century, several authors in the field
of sexual offending suggested that frontal lobe damages would lead to sexual
assaults while temporal lobe dysfunction would more directly be associated
(although rarely) with genuine sexual deviance or shift in sexual orientation (e.g.
Miller et al. 1986; Langevin 1990; Raine 1993). Thus, the frontal vs. temporal
opposition might distinguish the contact from the non-contact type of sexual
offenses. Insofar, however, both sexual and nonsexual assaults are associated with
the disruption of neural circuits that involve both the frontal and temporal lobes
(e.g. Volavka 2002). Recruiting distinct subgroups of sexual offenders in future
neuropsychological and/or brain imaging investigations might help differentiating
frontal from temporal anomalies among this group. It is also classically speculated
that sexual assaults might result from dysfunctional left fronto-temporal networks
provoking language and self-regulation deficits through impaired internalized
speech, which in turn would prevent the normal inhibition of emotions related with
sexual excitation (e.g. Galski et al. 1990 ). As aforementioned however, a more
generalized impulsivity deficit might affect both sexual and non-sexual assaulters.
As suggested more than 20 years ago by Graber et al. (1982) certain forms of
sexual deviations, including pedophilia, resemble more closely to a defect in
inhibitory systems than a dysfunctional “center” of sexual orientation or specific
verbal deficits. This might be especially true for sexual offences involving an
assault (e.g. Miller et al. 1986).
Finally, future investigations should explore the clinical utility of subgrouping
sexual offenders. In the present study, the number and severity of cognitive defects
were higher among pedophiles than rapists of adults. A growing number of
indications point toward this factor in neuropsychology, such as a correlation
between the I.Q. and the age of the victims (Cantor et al. 2004, 2005). It is plausible
that other factors related with the modus operandis (e.g. contact vs. non-contact
offences; coercive vs. non-coercive approaches; premeditated, planned sequestration
vs. unpremeditated, opportunistic impulsive aggression), the victims (e.g. children
vs. adults, intra- vs. extra-familial; exclusively females vs. both genders), the
offender (e.g. levels of cognitive distortions, intellectual capacities, and social
isolation) or subtypes of deviance (e.g. late onset vs. fixated) would help define more
heterogeneous subgroups, at least from the neuropsychological point of view. Thus,
the well-known divergence of neuropsychological findings in studies of sexual
offenders might reflect the heterogeneity of the group. The neuropsychological
approach might uncover abilities and limitations associated with each subgroup,
Sex Abuse (2007) 19:155–173169
which would be highly helpful for the understanding of the conditions and useful for
the elaboration of better tailored treatment plans.
the neuropsychological assessments.
The authors express their gratitude to Carine Doucet, M.Ps. for her assistance with
Absher, J. R., Vogt, B. A., Clark, D. G., Flowers, D. L., Gorman, D. G., Keyes, J. W., et al. (2000).
Hypersexuality and hemiballism due to subthalamic infarction. Neuropsychiatry Neuropsychology
and Behavioral Neurology, 13, 220–229.
Arnow, B. A., Desmond, J. E., Banner, L. L., Glover, G. H., Solomon, A., Polan, M. L., et al. (2002).
Brain activation and sexual arousal in healthy, heterosexual males. Brain, 125, 1014–1023.
Barkley, R. A. (1997). Behavioral inhibition, sustained attention, and executive functions: Constructing a
unifying theory of ADHD. Psychological Bulletin, 121, 65–94.
Bechara, A., Damasio, H., & Damasio, A. R. (2000). Emotion, decision making and the orbitofrontal
cortex. Cerebral Cortex, 10, 295–307.
Blanchard, R., Watson, M. S., Choy, A., Dickey, R., Klassen, P., Kuban, M., et al. (1999). Pedophiles:
Mental retardation, maternal age, and sexual orientation. Archives of Sexual Behavior, 28, 111–127.
Block, J. (1995). On the relation between IQ, impulsivity, and delinquency: Remarks on the Lynam,
Moffitt, and Southnamer-Loeber (1993) interpretation. Journal of Abnormal Psychology, 104, 395–
Blumer, D. (1970). Hypersexual episodes in temporal lobe epilepsy. American Journal of Psychiatry, 126,
Bogaert, A. F. (2001). Handedness, criminality, and sexual offending. Neuropsychologia, 39, 465–469.
Boone, K. B., Ghaffarian, S., Lesser, I. M., Hill-Gutierrez, E., & Berman, N. G. (1993). Wisconsin Card
Sorting Test performance in healthy, older adults: Relationship to age, sex, education, and IQ. Journal
of Clinical Psychology, 49, 54–60.
Bornstein, R. A. (1985). Normative data on selected neuropsychological measures from a nonclinical
sample. Journal of Clinical Psychology, 41, 651–658.
Burns, J. M., & Swerdlow, R. H. (2003). Right orbitofrontal tumor with pedophilia symptom and
constructional apraxia sign. Archives of Neurology, 60, 437–440.
Cantor, J. M., Blanchard, R., Christensen, B. K., Dickey, R., Klassen, P. E., Beckstead, A. L., et al. (2004).
Intelligence, memory, and handedness in pedophilia. Neuropsychology, 18, 3–14.
Cantor, J. M., Blanchard, R., Robichaud, L. K., & Christensen, B. K. (2005). Quantitative reanalysis of
aggregate data on IQ in sexual offenders. Psychological Bulletin, 131, 555–568.
Cardebat, D., Doyon, B., Puel, M., Goulet, P., & Joanette, Y. (1990). Formal and semantic lexical
evocation in normal subjects. Performance and dynamics of production as a function of sex, age and
educational level [in French]. Acta Neurologica Belgica, 90, 207–217.
Casanova, M. F., Mannheim, G., & Kruesi, M. (2002). Hippocampal pathology in two mentally ill
paraphiliacs. Psychiatry Research: Neuroimaging, 115, 79–89.
Cohen, J. (1992). A power primer. Psychological Bulletin, 112, 155–159.
Cohen, L. J., Nikiforov, K., Gans, S., Poznansky, O., McGeoch, P., Weaver, C., et al. (2002). Heterosexual
male perpetrators of childhood sexual abuse: A preliminary neuropsychiatric model. Psychiatric
Quaterly, 73, 313–336.
Cummings, J. L. (1985). Clinical neuropsychiatry. New York: Grune & Stratton.
Cummings, J. L., & Mendez, M. F. (1984). Secondary mania with focal cerebrovascular lesions. American
Journal of Psychiatry, 141, 1084–1087.
Davies, B. M., & Morgenstern, F. S. (1960). A case of cysticercosis, temporal lobe epilepsy, and
transvestism. Journal of Neurology, Neurosurgery & Psychiatry, 23, 247–249.
Delis, D. C., Kaplan, E., & Kramer, J. (2001). Delis-Kaplan Executive Function System. San Antonio, TX:
Dewhurst, K., Oliver, J. E., & McKnight, A. L. (1970). Socio-psychiatric consequence of Huntington’s
disease. British Journal of Psychiatry, 111, 255–258.
Dolan, M., Millington, J., & Park, I. (2002). Personality and neuropsychological function in violent,
sexual and arson offenders. Medicine, Science, and the Law, 42, 34–43.
170Sex Abuse (2007) 19:155–173
Epstein, A. W. (1961). Relationship of fetishism and transvestism to brain and particularly to temporal
lobe dysfunction. Journal of Nervous & Mental Disease, 133, 247–253.
Flor-Henry, P. (1987). Cerebral aspects of sexual deviation. In G. D.Wilson (Eds.), Variant sexuality:
Research and theory. Baltimore, MD: John Hopkins University Press.
Flor-Henry, P., Lang, R. A., Koles, Z. J., & Frenzel, R. R. (1991). Quantitative EEG studies of pedophilia.
International Journal of Psychophysiology, 10, 253–258.
Frohman, E. M., Frohman, T. C., & Moreault, A. M. (2002). Acquired sexual paraphilia in patients with
multiple sclerosis. Archives of Neurology, 59, 1006–1010.
Galski, T., Thornton, K. E., & Shumsky, D. (1990). Brain dysfunction in sex offenders. Journal of
Offender Rehabilitation, 16, 65–80.
Ghika-Schmid, F., Assal, G., De Tribolet, N., & Regli, F. (1995). Kluver–Bucy syndrome after left anterior
temporal resection. Neuropsychologia, 33, 101–113.
Gillespie, N. K., & Mckenzie, K. (2000). An examination of the role of neuropsychological deficits in
mentally disordered sex offenders. The Journal of Sexual Agression, 5, 21–29.
Gorman, D. G., & Cummings, J. L. (1992). Hypersexuality following septal injury. Archives of Neurology,
Goul, W. R., & Brown, M. (1970). Effects of age and intelligence on Trail Making Test performance and
validity. Perceptual and Motor Skills, 30, 319–326.
Graber, B., Hartmann, K., Coffman, J. A., Huey, C. J., & Golden, C. J. (1982). Brain damage among
mentally disordered sex offenders. Journal of Forensic Sciences, 27, 125–134.
Hartmann, M., & Potter, G. (1998). Sources of age differences on the Rey–Osterrieth Complex figure Test.
Clinical Neuropsychologist, 12, 513–524.
Heaton, R. K., Chelune, G. J., Talley, J. L., Kay, G. G., & Curtis, G. (1993). Wisconsin Card Sorting Test
manual: Revised and expanded. Odessa, FL: Psychological Assessment Resources.
Heaton, R. K., Grant, I., & Matthews, C. G. (1986). Differences in neuropsychological test performance
associated with age, education, and sex. In I. Grant, & K. Adhams (Eds.), Neuropsychological
assessment of neuropsychiatric disorders. NewYork: Oxford University Press.
Hendricks, S. E., Fitzpatrick, D. F., Hartmann, K., Quaife, M. A., Stratbucker, R. A., & Graber, B. (1988).
Brain structure and function in sexual molesters of children and adolescents. Journal of Clinical
Psychiatry, 49, 108–112.
Hoenig, J., & Kenna, J. C. (1979). EEG abnormalities and transsexualism. British Journal of Psychiatry,
Hucker, S., Langevin, R., Dickey, R., Handy, L., Chambers, J., & Wright, S. (1988). Cerebral damage and
dysfunction in sexually aggressive men. Annals of Sex Research, 1, 33–47.
Hucker, S., Langevin, R., Wortzman, G., Bain, J., Handy, L., Chambers, J., et al. (1986).
Neuropsychological impairment in pedophiles. Canadian Journal of Behavioral Sciences, 18, 440–
Hunter, R., Logue, V., & McMenemy, W. H. (1963). Temporal lobe epilepsy supervening on longstanding
transvestism and fetishism. Epilepsia, 4, 60–65.
Huws, R., Schubsachs, A. P. W., & Taylor, P. J. (1991). Hypersexuality, fetishism and multiple sclerosis.
British Journal of Psychiatry, 158, 280–281.
Kelly, T., Richardson, G., Hunter, R., & Knapp, M. (2002). Attention and executive function deficits in
adolescent sex offenders. Neuropsychological Development and Cognition, Section C. Child
Neuropsychology, 8, 138–143.
King, M. C. (1981). Effects of non-focal brain dysfunction on visual memory. Journal of Clinical
Psychology, 37, 638–643.
Kolarsky, A., Freund, K., Machek, J., & Polak, O. (1967). Male sexual deviation. Association with early
temporal lobe damage. Archives of General Psychiatry, 17, 735–743.
Krafft-Ebing, R. V. (1886/1965). Psychopathia sexualis. (english translation). New York: Putnam.
Lang, R. A. (1993). Neuropsychological deficits in sexual offenders: Implications for treatment. Sexual
and Marital Therapy, 8, 181–200.
Langevin, R. (1990). Sexual anomalies and the brain. In: W. L. Marshall, D. R. Laws, & H. E. Barbaree
(Eds.), Handbook of sexual assaults. New York: Plenum.
Langevin, R., Bain, J., Ben-Aron, M. H., Coulthard, R., Day, D., Handy, L., et al. (1985). Sexual
aggression: Constructing a predictive equation. A controlled pilot study. In R. Langevin (Ed.), Erotic
preference, gender identity, and aggression in men: New research studies. Hillsdale, NJ: Erlbaum.
Langevin, R., Ben-Aron, M. H., Wortzman, G., Dickey, R., & Handy, L. (1987). Brain damage, diagnosis,
and substance abuse among violent offenders. Behavioral Sciences and the Law, 5, 77–94.
Sex Abuse (2007) 19:155–173 171
Langevin, R., Ben-Aron, M. H., Wright, P., Marchese, V., & Handy, L. (1988a). The sex killer. Annals of
Sex Research, 1, 263–301.
Langevin, R., Lang, R. A., Wortzman, G., Frentzel, R. R., & Wright, P. (1989b). An examination of brain
damage and dysfunction in genital exhibitionists. Annals of Sex Research, 2, 77–87.
Langevin, R., Wortzman, G., Dickey, R., Wright, P., & Handy, L. (1988b). Neuropsychological
impairment in incest offenders. Annals of Sex Research, 1, 401–415.
Langevin, R., Wortzman, G., Wright, P., & Handy, L. (1989a). Studies of brain damage and dysfunction in
sex offenders. Annals of Sex Research, 2, 163–179.
Lesniak, R., Szymusik, A., & Chrzanowski, R. (1972). Case report: Multidirectional disorders of sexual
drive in a case of brain tumor. Forensic Science, 1, 333–338.
Lezak, M. D., Howieson, D. B., & Loring, D. W. (2004). Neuropsychological assessment (4th Ed). New
York: Oxford University Press.
Marlowe, W. B., Mancall, E. L., & Thomas, J. J. (1975). Complete Klüver–Bucy syndrome in man.
Cortex, 11, 53–59.
Martin, J. E. (1999). Assessment of executive functions in sexual offenders. Dissertation Abstracts
International: Section B: The Sciences & Engineering, 59 (10-B), 5580. US: University Microfilms
Mega, M. S., & Cummings, J. L. (1994). Frontal-subcortical circuits and neuropsychiatric disorders. The
Journal of Neuropsychiatry and Clinical Neurosciences, 6, 358–370.
Mendez, M. F., Chow, T., Ringman, J., Twitchell, G., & Hinkin, C. H. (2000). Pedophilia and temporal
lobe disturbances. Journal of Neuropsychiatry and Clinical Neuroscience, 12, 71–76.
Mendez, M. F., O’Connor, S. M., & Lim, G. T. (2004). Hypersexuality after right pallidotomy for
Parkinson’s disease. Journal of Neuropsychiatry and Clinical Neuroscience, 16, 37–40.
Miller, A. D. (1998). Executive function deficits in incarcerated adolescent sexual offenders as measured
by the Wisconsin Card Sorting Test. Dissertation Abstracts International: Section B: The Sciences &
Engineering, 58 (12-B), 6817. US: University Microfilms International.
Miller, B. L., Cummings, J. L., McIntyre, H., Ebers, G., & Grode, M. (1986). Hypersexuality or altered
sexual preference following brain injury. Journal of Neurology, Neurosurgery and Psychiatry, 49,
Milner, B. (1963). Effects of different brain lesions on card sorting: The role of the frontal lobes. Archives
of Neurology, 9, 90–100.
Mitchell, W., Falconer, M. A., & Hill, D. (1954). Epilepsy with fetishism relieved by temporal lobectomy.
Lancet, 267, 626–630.
Mitrushina, M., Boone, K. B., & D’Elia, L. F. (2005). Handbook of Normative Data for
Neuropsychological Assessment (2nd Ed). New York: Oxford University Press.
Monga, T. N., Monga, M., Raina, M. S., & Hardjasudarma, M. (1986). Hypersexuality in stroke. Archives
of Physical Medicine and Rehabilation, 67, 415–417.
O’Carroll, R. (1989). A neuropsychological study of sexual deviation. Sexual and Marital Therapy, 4,
Ortego, N., Miller, B. L., Itabashi, H., & Cummings, J. L. (1993). Altered sexual behavior with multiple
sclerosis: A case report. Neuropsychiatry Neuropsychology, and Behavioral Neurology, 6, 260–264.
Raine, A. (1993). The psychopathology of crime. Criminal Behavior as a Clinical Disorder. New York:
Raine, A., & Buchsbaum, M. S. (1996). Violence, brain imaging, and neuropsychology. In D. Stoff, & R.
B. Cairns (Eds.), Aggression and violence: Genetic, neurobiological, and biosocial perspectives. New
Redouté, J., Stoleru, S., Gregoire, M. C., Costes, N., Cinotti, L., Lavenne, F., et al. (2000). Brain
processing of visual sexual stimuli in human males. Human Brain Mapping, 11, 162–177.
Regestein, Q. R., & Reich, P. (1978). Pedophilia occurring after onset of cognitive impairment. Journal of
Nervous and Mental Disease, 166, 794–798.
Rubenstein, J. A. (1992). Neuropsychological and personality differences between controls and
pedophiles. Dissertation Abstracts International, Section B—The Science and Engineering, 53 (5-
B), 2553. US: University Microfilms International.
Ruffolo, L. F., Guilmette, T. J., & Willis, W. G. (2000). Comparison of time and error rates on the Trail
Making Test among patients with head injuries, experimental malingerers, patients with suspect effort
testing, and normal controls. Clinical Neuropsychologist, 14, 223–230.
Ryan, J. J., Paolo, A. M., & Findley, G. (1991). Percentile rank conversion tables for WAIS-R IQs at six
educational levels. Journal of Clinical Psychology, 47, 104–107.
172Sex Abuse (2007) 19:155–173
Schreiber, H. E., Javorsky, D. J., Robinson, J. E., & Stern, R. A. (1999). Rey-Osterrieth Complex Figure Download full-text
performance in adults with attention deficit hyperactivity disorder: A validation study of Boston
Qualitative Scoring System. Clinical Neuropsychologist, 13, 509–520.
Scott, M. L., Cole, J. K., McKay, S. E., Golden, C. J., & Liggett, K. R. (1984). Neuropsychological
performance of sexual assaulters and pedophiles. Journal of Forensic Sciences, 29, 1114–1118.
Spreen, O., & Strauss, E. (1998). A compendium of neuropsychological tests (2nd edn.). New York:
Oxford University Press.
Starkstein, S. E., & Kremer, J. (2001). The disinhibition syndrome and frontal-subcortical circuits. In D.
G. Lichter & J. L. Cummings (Eds.), Frontal-subcortical circuits in psychiatric and neurological
disorders (pp. 163–176). New York: The Guilford Press.
Stein, D. J., Black, D. W., & Pienaar, W. (2000a). Sexual disorders not otherwise specified: Compulsive,
addictive or impulsivity? CNS Spectrum, 5, 60–64.
Stein, D. J., Hugo, F., Oosthuizen, P., Hawkridge, S. M., & Van Heerden, B. (2000b). Neuropsychiatry of
hypersexuality. CNS Spectrums, 5, 36–46.
Stoleru, S., Redouté, J., Costes, N., Lavenne, F., Bars, D.L., Dechaud, H., et al. (2003). Brain processing
of visual sexual stimuli in men with hypoactive sexual desire disorder. Psychiatry Research:
Neuroimaging, 124, 67–86.
Stone, M. H., & Thompson, E. H. (2001). Executive function impairment in sexual offenders. The Journal
of Individual Psychology, 57, 51–59.
Stratta, P., Rossi, A., Mancini, F., Cupillari, M., Mattei, P., & Casacchia, M. (1993). Wisconsin Card
Sorting Test performance and educational level in schizophrenic and control samples. Neuropsychi-
atry, Neuropsychology, & Behavioral Neurology, 6(3), 149–153.
Stuss, D. T., & Knight, R. T. (Eds.) (2002). Principles of frontal lobe function. New York: Oxford Press.
Toone, B. K., Edeh, J., Nanjee, M. N., & Wheeler, M. (1989). Hyposexuality and epilepsy: A community
survey of hormonal and behavioural changes in male epileptics. Psychological Medicine, 19, 937–
Volavka, J. (2002). Neurobiology of violence. (2nd ed.). Washington: American Psychiatric Publishing.
Waismann, R., Fenwick, P. B., Wilson, G. D., Hewett, T. D., & Lumsden, J. (2003). EEG responses to
visual erotic stimuli in men with normal and paraphilic interests. Archives of Sexual Behavior, 32,
Walinder, J. (1965). Transvestism, definition and evidence in favor or occasional deviation from cerebral
dysfunction. International Journal of neuropsychiatry, 1, 567–573.
Ward, T., & Beech, A. (2006). An integrated theory of sexual offending. Aggression and Violent Behavior,
Wiens, A. N., Tindall, A. G., & Crossen, J. R. (1994). California verbal learning test: A normative data
study. The Clinical Neuropsychologist, 8, 75–90.
Wright, P., Nobrega, J., Langevin, R., & Wortzaman, G. (1990). Brain density and symmetry in pedophilic
and sexually aggressive offenders. Annals of Sex Research, 3, 319–328.
Yeudall, L. T., & Fromm-Auch, D. (1979). Neuropsychological impairments in various psychopatholog-
ical populations. In J. Gruzelier, & P. Flor-Henry (Eds.), Hemisphere asymmetries of function in
psychopathology. New York: Elsevier.
Zasler, N. D. (1994). Sexual dysfunction. In J. M. Silver, S. C. Yudofsky, & R. E. Hales (Eds.),
Neuropsychiatry of traumatic brain injury. Washington: American Psychiatric Press.
Sex Abuse (2007) 19:155–173 173