Psychology of Criminal Behaviour: A Canadian Perspective Chapter 9: Sexual Offenders
CHAPTER 9: Sexual Offenders
1. Review the scope of sex offending and consequences for victims.
2. Introduce the paraphilias and their diagnostic criteria.
3. Cover some of the major theories explaining the initiation of sex offending.
4. Examine some typologies of sex offenders.
5. Review key research on factors associated with the initiation of sex offending.
6. Examine observed rates of sexual recidivism and predictors of sexual recidivism.
7. Introduce some of the key assessment instruments used to estimate risk of
recidivism among sex offenders.
8. Consider various approaches to the treatment and management of sex offenders
and the extent to which these approaches are effective in reducing sexual
A significant minority of the population are victims of sexual offences. The majority
of sex offences are not reported to the police, and sex offences are less likely to be
reported than other violent crimes. Of the sex offences that are reported, approximately
one-third are not cleared. Of the sex offences that are cleared and result in a
conviction, approximately half result in a sentence of incarceration.
The vast majority of sex offences are committed by male offenders. Both sexual
offending and victimization are more common among younger people. Offenders and
victims know each other (e.g., acquaintances, friends, family members) prior to the
sexual offence in the majority of incidents. Sexual victimization is associated with a
number of negative emotional reactions as well as physical and psychological problems.
Contrary to public opinion, there is no evidence that sex offences are on the
rise in Canada.
Sex offenders are heterogeneous. Their characteristics, motivation, and behaviour
vary considerably across and even within offence type.
Some paraphilias can manifest as sexual offending; specifically, pedophilia, sexual
sadism, frotteurism, exhibitionism, and voyeurism. However, it is important to
remember that paraphilia and sex offending are not synonymous. For example, one
can be a pedophile but never commit a sex offence against a child and one can commit
a sex offence against a child but not be a pedophile.
There is considerable overlap and convergence in most theories and models of the
initiation of sexual offending. A number of factors likely combine and interact to
cause sex offending. It is generally difficult to research the causal factors, but numerous
observational studies suggest the following are associated with the initiation of
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sex offending against adults or children: childhood sexual victimization, deviant sexual
interests, general antisociality, low self-esteem, intimacy deficits, poor social
skills, beliefs supportive of sex offending, and neurodevelopmental perturbations.
Sexual recidivism rates are generally low; relatively few sex offenders are charged with
new sex offences after their initial conviction. The best predictors of sexual recidivism
are sexual deviance and general antisociality. Risk factors can be static, stable dynamic,
or acute dynamic. Static risk factors indicate a baseline of risk and an estimate of the
likelihood of sexual reoffending over the long term. Stable dynamic factors indicate
potential treatment targets and permit measurement of improvement or deterioration
over time. Acute dynamic factors indicate the imminence of sexual recidivism.
Subgroups of sex offenders who have higher rates of recidivism can be identified and
managed by assessing static and dynamic risk factors with risk-assessment instruments.
The accuracy with which sexual recidivism is predicted is highest for empirical
actuarial and mechanical instruments and lowest for unstructured clinical judgment.
The predictive accuracy of structured professional judgment approaches falls between
actuarial and unstructured clinical judgment.
Researchers generally find lower recidivism rates among treated compared to untreated
sex offenders. And programs that follow the general principles of effective corrections
appear to be more effective than programs that do not. Although these findings are very
encouraging, debate continues about whether the lower rates of recidivism associated
with sex offender treatment actually demonstrate that it is effective because the
research methodology used in most studies leaves the results open to alternate
More creative and innovative research will move us closer to resolving these
and other important questions about sex offenders.
Reading the opening vignette and considering sex offences presented in
the media raises a number of intriguing questions.
How common is this sort of behaviour?
What are the causes of sexual offending?
What are the prototypical characteristics of sex offenders?
After being caught, do sex offenders typically persist with sex
What can be done to identify the most persistent sex offenders and
reduce their risk of sexual recidivism?
we will consider the scope and characteristics of sexual offending in
A number of psychiatric disorders called paraphilias relevant to sexual
offending will be discussed.
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We will also review a number of key theories that attempt to explain why
some people sexually offend.
Research examining the association between sex offending and some of
the factors identified in theory will also be reviewed.
We will then present research findings on predictors of sexual recidivism,
a number of key sex offender risk assessment instruments, and the
research on the predictive accuracy of these instruments.
Finally, some of the major approaches to treatment for sex offenders will
be presented and research on the effectiveness of treatment will be
Scope of Sexual Offending
Before examining sex offenders themselves, it is important to consider the
scope of sex offending.
Estimates of offending are typically derived from two main sources:
surveys of the public and police reports.
In 2004, a representative sample (territories excluded) of people over the
age of 14 in 24 000 Canadian households was telephoned (random digit
Sexual attack: During the past 12 months, has anyone forced you or
attempted to force you into any unwanted sexual activity, by
threatening you, holding you down or hurting you in some way?
Unwanted sexual touching: During the past 12 months, has anyone
ever touched you against your will in any sexual way? By this I
mean anything from unwanted touching or grabbing, to kissing or
Considering both types of sexual assault (i.e., sexual attacks and unwanted
sexual touching), approximately 512 200 people in Canada reported
having been sexually assaulted in the past 12 months on the 2004 GSS
Few of these offences were reported to the police.
Responses on the GSS indicate that less than 10 percent of sexual assaults
The reporting rate was slightly higher (22 percent) when only more violent
forms of sexual assault (i.e., sexual attacks) were considered.
for all forms of sexual assault, the rate of reporting to police was
considerably lower than for other violent offences (robbery, 47 percent;
physical assault, 40 percent).
Victims’ reasons for not reporting sexual assault incidents to the police
most commonly included: “felt it was not important enough” (58 percent),
“incident was dealt with in another way” (54 percent), “felt it was a
personal matter” (47 percent), or “did not want to get involved with the
police” (41 percent).
Another valuable source of information about the scope of sex offending
in Canada is the Uniform Crime Reporting (UCR) Survey.
The UCR Survey reports on the incidence of crimes reported to police in a
given year and some of the characteristics of those crimes.
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In contrast to the GSS on Victimization, the UCR Survey includes
offences against victims of all ages and includes the territories as well as
On the UCR Survey, sexual offences include sexual assaults of varying
severity (i.e., Levels 1, 2, and 3) and other sexual offences, many of which
are against children (e.g., sexual interference and invitation to sexual
In 2007, 73 sexual offences were reported per 100 000 people in Canada.
The UCR Survey also tracks clearance rates.
Clearance refers to laying charges or otherwise resolving reported
offences (e.g., complainant asks that charges not be laid, accused is
deceased, or police discretion).
Clearance rates were lower for sexual offences than other violent offences
Over one-third (37 percent) of sexual offences were not cleared by police,
whereas only 26 percent of other violent offences were not cleared.
In terms of sentencing, convictions for sexual offences (54 percent) were
more likely to result in custodial sentences (e.g., prison rather than
probation only) than other violent offences (30 percent) for adult offenders
Contrary to what people might hear in the popular media, there is no
evidence that sexual offending is on the rise.
Neither self-reported (GSS) nor police-reported (UCR Survey) data show
an increase in victimization over the past five to ten years.
Although any amount of sex offending is a serious concern, its frequency
does not appear to be increasing.
more serious types of sexual offences are relatively rare.
The minority of sexual assaults reported in the 2004 GSS were sexual
attacks (19 percent); most were incidents of unwanted sexual touching (81
14 percent of sexual offences reported to the police in 2007 were for Level
2 or 3 sexual assaults and other sexual offences; most were for Level 1
sexual assault (86 percent).
only the minority of cases fit the sensational sexual offences often
portrayed in the media.
The GSS and UCR Survey indicate that women and girls are more likely
to be victims of sexual offences than men and boys.
Young people are at greater risk for sexual victimization.
Most sexual offences reported on the GSS were against victims aged 15 to
24 and the rates dropped off steeply as victim age increased (recall that the
GSS does not include anyone under 15).
the UCR Survey indicates that the majority of sexual offences are
committed against victims under the age of 18 (25 percent below age 12).
UCR Survey data indicate that men are more often the offenders in sexual
crimes (97 percent) than in other violent offences (78 percent).
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Sexual offences reported to the police in 2007 were committed
considerably more often by young people (rates for youth aged 12–17
were 90 per 100 000 people) than even slightly older people (e.g., rates for
18–34-year-olds were 55 per 100 000).
Both GSS and UCR Survey data indicate that the offender and victim
often know each other (e.g., acquaintances, friends, family members) prior
to the sexual offence in the majority of incidents.
Children are most often victimized by family members, whereas
adolescents and adults are most often victimized by acquaintances or
Consequences for Victims
Physical injury to victims occurs in relatively few sexual offences (7
percent on the GSS and 23 percent on the UCR Survey).
On the GSS, victims reported a number of negative emotional reactions
following the sexual assault: anger (24 percent); confusion and frustration
(20 percent); shock and disbelief (16 percent); annoyance (16 percent);
and fear (15 percent).
More generally, sexual assault and child sexual abuse are associated with a
number of negative outcomes, such as concerns about sexually transmitted
diseases and pregnancy, post-traumatic stress disorder (PTSD),
depression, and sexual disturbances.
Paraphilias, as defined in the Diagnostic and Statistical Manual of
Mental Disorders(DSM-IVTR) “are recurrent, intense sexually arousing
fantasies, sexual urges, or behaviors generally involving
1. nonhuman objects,
2. the suffering or humiliation of oneself or one’s partner, or
3. children or other non-consenting persons that occur over a period of at
least 6 months”
Not all paraphilias involve illegal behaviour (e.g., fetishism), but many
can manifest as sexual offending; specifically, pedophilia, sexual sadism,
frotteurism, exhibitionism, and voyeurism.
Pedophilia comes from the Greek words pedeiktos (young children) and
philia (love) and generally refers to a sexual preference for children who
have not yet begun puberty
The specific diagnostic criteria for pedophilia in the DSM-IV-TR are:
1. Over a period of at least 6 months, recurrent, intense sexually
arousing fantasies, sexual urges, or behaviors involving sexual
activity with a prepubescent child or children (generally age 13 years
2. The person has acted on these sexual urges, or the sexual urges or
fantasies cause marked distress or interpersonal difficulty.
3. The person is at least age 16 years and at least 5 years older than the
child or children in Criterion 1.
Although the terms pedophile and child molester are often used
interchangeably, they are NOT synonymous.
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Some adults who sexually abuse prepubescent children are not pedophiles
and some pedophiles do not sexually abuse children.
Child sexual abuse can be motivated by a number of factors besides a
sexual preference for prepubescent children.
Sexual sadism refers to being sexually aroused by inflicting humiliation
or pain on others.
Even among sex offenders, sexual sadism is relatively rare, but because of
the extreme victim injury often associated with sexual sadism, it is a
concern with both rapists and child molesters.
Frotteurism is an interest in touching and rubbing against a non-
These acts often occur in crowded places (e.g., full subway car) where the
frotteur can more easily access victims and avoid detection.
Exhibitionism refers to an interest in exposing one’s genitals to an
Voyeurism involves an interest in observing unsuspecting people naked
or engaging in sexual activity.
2. Explaining Sex Offending:
A number of theories have attempted to address this question and explain
the initiation of sex offending.
attempted to organize existing explanations of child sexual abuse into a
multifactor framework, which reflects four underlying factors he identified
in the literature.
The first is emotional congruence and refers to a perceived “‘fit’ between
the adult’s emotional needs and the child’s characteristics”
An individual may find sexual contact with a child emotionally gratifying
because he or she is psychologically immature and views him or herself as
some individuals may feel emotionally gratified by sexually abusing a
child because they feel powerful and competent when doing so
Emotional congruence alone would not necessarily lead to sexual abuse of
What is also needed is some degree of sexual arousal to the prospect of
sexual contact with a child, which is the second factor in this model.
This need not be as extreme as pedophilia, but there must be at least some
arousal to children.
Blockageis the third factor and refers to the idea that some people may be
blocked from meeting their sexual and emotional needs in prosocial ways
(e.g., consenting sexual contact with adults).
Blockage may occur because of social anxiety, social skills deficits,
problems in a current romantic relationship, or repressive beliefs about
sexual norms (e.g., against masturbation and extramarital affairs).
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The final factor, disinhibition, refers to the fact that inhibitions against
child sexual abuse are either circumvented or are absent to allow one to
act on his or her sexual interest in children.
Disinhibition may occur because of personality (e.g., impulse control
deficits, lack of empathy), situational (e.g., intoxication, extreme stress),
or cultural factors.
not all four factors are necessary for a person to sexually abuse a child, but
they likely work as complementary processes, possibly having additive or
“many people have important prerequisite components to engaging in
child molesting, but never do.
Theories from only one level of the model will never accurately
discriminate between those who engage and do not engage in such
Sex abusers will always show up as having some of these characteristics,
such as arousal to children, shyness, impulsivity, or need for dominance,
but there will also be large numbers of non-abusers in the population at
large who have these characteristics too
Integrated Theory of the Etiology of Sexual Offending
This model proposed a biopsychosocial explanation of sexual offending
against adults or children.
biological, developmental, socio-cultural, and transitory situational factors
can create a proclivity to sexually offend.
Concerning the biological contribution, the default position for men is the
fusion of sex and aggression.
If a boy’s childhood experiences and culture do not teach him to inhibit
aggression in the context of sexuality, sexual offending may be likely once
he reaches puberty.
Although this is the default biological position, the researchers argue that
environmental factors are the primary determinants of whether one
becomes a sexual offender.
Negative childhood experiences, such as abuse and neglect from
caregivers, lead to insecure childhood attachment and provide models of
aggressive and self-centred antisocial behaviour.
Consequently, the child enters puberty without the social skills and self-
confidence required to establish relationships with peer-aged partners.
Inability to secure intimate relationships with peer-aged partners may then
lead a young man to turn his sexual attention to children, who are viewed
as less rejecting and intimidating than peers, or to sexually aggress against
This may occur first in his masturbation-accompanied fantasies, which
would condition arousal to children or violence, and then occur in actual
The researchers argue that socio-cultural messages and situational factors
may interact with a vulnerable predisposition to increase or decrease the
likelihood of sexual offending against children or peers.
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Transitory situational factors also interact with predispositions and can
either inhibit or facilitate sexual aggression.
The biological, childhood, socio-cultural, and transitory situational factors
are thought to interact with one another to produce varying levels of
propensity for sexual offending.
Quadripartite Model of Sexual Aggression against Adults
This model proposed a quadripartite model to explain why some men
sexually assault women.
The four factors are physiological sexual arousal, cognitions that justify
sexual aggression, affective dyscontrol, and personality problems.
Sexual arousal to rape or generally high levels of sexual arousal are
thought to increase the likelihood of rape.
A variety of cognitions may also increase the likelihood of rape.
Affective dyscontrol refers to anger and hostility as motivating sexual
Sexual assault may also be motivated by personality problems, particularly
antisocial personality features, which may be rooted in adverse
developmental experiences such as parental divorce, criminality among
family members, neglect, physical abuse, or sexual abuse.
Not all four factors are necessary for sexual assault to occur
it generally becomes more likely as the number of factors present
The relative strength of influence among these four factors varies across
offenders to create subtypes; for example, for some offenders sexual
arousal may be the dominant factor leading to sexual offending, whereas
for others the primary motivational precursor may be cognitions that
justify sexual offending.
Quadripartite Model of Sexual Aggression against Children
Hall and Hirschman (1992) also applied their quadripartite model to
explain sexual offending against children.
The first factor is physiological sexual arousal to children.
The second factor, cognitions that justify sexual abuse of children, refers
to beliefs such as that sexual contact with children is not harmful or wrong
and is enjoyable for victims.
Such beliefs are often called cognitive distortions.
Child sexual abuse may also result from negative affective states.
It may be an attempt to cope with negative affective states (i.e.,
depression), or, less commonly, an expression of anger and hostility.
The final factor, personality problems, refers to developmentally related
personality problems or disorders, which can manifest as emotional
difficulties, poor social skills, or impulsivity.
One of these four factors or various combinations of these factors can lead
to child sexual offending.
The relative strength of influence among the factors varies across
offenders to create subtypes; e.g., for some offenders sexual arousal to
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children may be the dominant factor leading to sexual offending against a
Hierarchical-Mediational Confluence Model (HMC)
This is an etiological model of sexual aggression against women derived
from his extensive
The model is an ongoing process and has been revised over the years,
incorporating new research findings.
According to the model, there are two major paths that lead to sexual
aggression: the antisocial and impersonal sex path and the hostile
In the antisocial path, abusive home environments (e.g., physical
violence between parents and childhood physical or sexual abuse) lead to
early delinquent behaviour (e.g., delinquent peers, running away), which
leads to impersonal sexuality (e.g., young age at first intercourse and many
sexual partners), which in turn leads to sexual aggression.
In the hostile masculinity path, attitudes accepting violence toward
women (e.g., rape myth acceptance and acceptance of interpersonal
violence) lead to narcissism, hostility toward women, and sexual
dominance, which in turn lead to sexual aggression.
In addition to an independent influence on sexual aggression, these
constellations also interact with each other, such that an increasing number
of risk factors greatly increases the risk of sexual aggression.
empathy and nurturing personality characteristics moderate the influence
of the risk factors listed above. Specifically, for men who are low in
empathy and nurturance (egotistical and self-oriented), the risk factors
listed are strongly associated with sexual aggression.
for men who are high in empathy and nurturance (empathic and other-
oriented), the risk factors are only weakly related to sexual aggression.
Evolutionary Explanation of Rape
Evolutionary psychology involves the idea is that in our ancestral
environments, certain physiological, psychological, and behavioural
characteristics were associated with increased reproductive success (i.e.,
having a relatively high number of children who in turn have a relatively
high number of children, and so on).
To the extent that such characteristics are heritable, the genes responsible
for them would be passed on to subsequent generations more so than
genes that are responsible for characteristics associated with reproductive
Today, we generally think and do what led to reproductive success in
A very important thing to
in evolutionary psychology there is the distinction between proximal and
ultimate causes: Proximal causes are immediate influences that motivate
or otherwise drive behaviour, whereas ultimate causes refer to the
reproductive fitness selection pressures of ancestral environments.
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People are driven by proximal influences, but these influences may have
been shaped by ultimate causes.
most people do not consciously choose to have sex with the opposite sex
instead of trees because they want to maximize their reproductive fitness.
Instead, most people are simply driven by their attraction to the opposite
Adaptive does not necessarily equal “good” in a moral sense.
Some of the behaviours people view as immoral and wrong may have
been adaptive in our ancestral environments.
Conversely, some acceptable behaviours (e.g., homosexuality, celibacy)
would not have been adaptive in our ancestral environments.
the evolutionary psychological perspective neither condones nor
condemns any characteristics or behaviours, but rather seeks to explain
It is an important perspective to consider because it may provide a fuller
understanding of why such behaviours occur and how to deal with them.
A final distinction to make is between mating effort and parental
Both are reproductive strategies at opposite ends of a continuum.
Mating effort refers to a short-term, low-investment approach to mating in
which the focus is partner variety and casual sex.
Parental investment, in contrast, refers to a long-term investment in
ensuring the health and well-being of one’s offspring.
Although the most successful strategy would usually have been a blend of
both approaches, high mating effort may have been a reproductively
successful strategy depending on the individual and the conditions.
For most mammals, including humans, the minimal parental investment is
much lower for males than females.
The man’s minimal investment is limited to the time and sperm it takes to
impregnate a woman, whereas the woman’s minimal investment goes well
beyond sexual intercourse to include carrying the fetus and giving birth
along with all the physical demands and health risks of pregnancy and
Although many men willingly choose to invest in their partner and
offspring, they have the option of choosing not to do so.
This discrepancy in minimal parental investment resulted in different
selection pressures for men and women in ancestral environments.
sexual intercourse was more costly for women than men in terms of
minimal parental investment: women who were more selective about
mates both in terms of attractiveness and status were more likely to have
successful offspring than women who mated indiscriminately.
because of the difference in minimal parental investment, there was (and
is) less variability across women in the number of offspring they would
produce compared to men.
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a man could, at least theoretically, impregnate hundreds if not thousands
of women every year of his adult life; the main limits would be
opportunity and stamina.
The model attempts to explain sexual assault from an evolutionary
rape is part of a general antisocial, aggressive, and risk-tolerant lifestyle
and that very few rapists specialize in rape
most rapists fall into one of three groups: young men, competitively
disadvantaged men, or psychopaths.
Adolescent and young men typically have relatively few resources and
low status, which puts them at a competitive disadvantage relative to other
males with whom they are competing for mates.
Through violence (including sexual coercion) and general risk taking,
these young men may be able to increase their status, resources, and/or
access to more and better mates.
as they move into adulthood and begin to acquire legitimately gained
resources and status, they switch from high mating effort to high parental
So the sexual assaults and other antisocial behaviour of this group are
limited to adolescence and young adulthood.
This is the most common type of rapist.
This desistance with adulthood does not occur for the competitively
Their sexual coercion and other antisocial behaviour is life-course
The ability to compete for resources and status in prosocial ways is
impaired by early neuro-developmental insults, such as obstetrical
complications and low IQ.
Because men in this group do not have the skills or abilities to achieve
status and resources in prosocial ways, they maintain their high mating
effort and antisocial approach into adulthood.
The psychopaths are also life-course persistent.
In contrast to the competitively disadvantaged men, psychopaths are not
competitively disadvantaged but select high mating effort over parental
investment as an alternate strategy.
The competitively disadvantaged and psychopaths are thought to make up
a small proportion of rapists.
Seto’s Developmental Theory of Child Sexual Offending
This model draws from a very broad literature of theory and research.
It is somewhat similar to the model above in that there is an adolescence-
limited path, a pedophilia path, and an antisociality path, which includes
the sub-paths of competitive disadvantage and psychopathy.
adolescence-limited child molesters are those who may be blocked from
romantic relationships with peers because of lack of resources (e.g.,
unattractive, poor, weak) or poor social skills.
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These boys may occasionally sexually abuse a child.
Some adolescence-limited offenders may also be pedophiles, motivated by
their sexual interest in children.
persistent offending may be a manifestation of antisociality, stemming
from enduring competitive disadvantage or psychopathy.
Sexual attraction to prepubescent children (pedophilia) would be another
cause of child molestation.
Offending against children would be especially likely when both
antisociality and pedophilia are present.
Massachusetts Treatment Centre: Child Molester Typology, Version 3 (MTC:CM3)
This typology reflects the heterogeneity of child molesters
The MTC:CM3 was developed with 177 extra-familial child molesters
(only contact sex offences; at least one victim outside the family; victims
under 16 years old) civilly committed (from one day to life) for their sex
offences and evaluated at the MTC between 1959 and 1981.
There are two orthogonal (or distinct) axes on which child molesters can
On the first axis, child molesters are differentiated by their level of
fixation, which refers to the extent of their pedophilic interests: child
molesters who think and fantasize about sexual contact and interpersonal
relationships primarily with children would be high on fixation.
Each of these groups can be further differentiated by their degree of social
competence, which reflects their degree of achievement with regards to
adult responsibilities and relationships: someone with an unstable
employment history, no long-term live-together sexual relationships with
adults, no involvement in any adult-oriented organizations, and no adult
friends would be considered extremely low in social competence.
Axis I defines four types of child molesters differing in their degree of
pedophilic and social competence.
On Axis II, child molesters are first differentiated by the amount of time
they have spent with children in both sexual offence and non-sexual
situations: child molesters who are involved in work or leisure activities
that put them in close proximity to children, such as a school teacher or
coach of a children’s sports team, would be considered high contact.
The high-contact child molesters are further differentiated by the meaning
of their contact with children: interpersonal versus narcissistic.
For the interpersonal type, the goal is to establish interpersonal
relationships with children, whereas for the narcissistic type, the
motivation for contact is exclusively sexual.
So the interpersonal type (Type 1) views the sexual abuse as a mutually
satisfying romantic relationship, whereas the narcissistic type (Type 2) is
self-focused and views the sexual abuse primarily as a means to achieve
his own sexual gratification.
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Like the high-contact child molesters, low-contact child molesters can also
be further differentiated.
First, they are distinguished by the degree of physical injury they inflict on
their victims: low physical injury versus high physical injury.
These subgroups are further differentiated by their degree of sadism.
Type 3 (Exploitative, Nonsadistic) inflicts little physical injury on victims.
If any aggression is used, it is instrumental (i.e., aggression may be used to
gain compliance from victims and the amount of aggression does not
exceed what is required to gain compliance), and this aggression is not
sexually arousing for the offender.
Type 4 (Muted Sadistic) has sadistic sexual interests and fantasies (i.e., is
aroused by the pain, fear, and humiliation of victims) but does not act on
them enough to cause physical injury to victims.
Type 5 (Nonsadistic, Aggressive) uses violence causing physical injury to
victims, which is either accidental or motivated by anger, but in neither
case is it sexually arousing for the offender.
Type 6 (Sadistic) inflicts injury on victims and is sexually aroused by their
pain, fear, and humiliation.
Massachusetts Treatment Centre: Rapist Typology, Versions 3
A typology of rapists.
The most familiar and commonly referred to version of their rapist
typology is the Massachusetts Treatment Centre: Rapist Typology,
Version 3 where rapists are distinguished by four primary motivations:
opportunity, generalized anger, sexual gratification, and misogynistic
Opportunistic rapists (Types 1 and 2) are generally antisocial and
impulsive men who commit sexual assault when the opportunity to do so
presents itself (i.e., a potential victim in the right context).
these rapists may commit sexual assault during the course of burglary if a
woman happens to be present in the home.
They are more influenced by situational factors than driven by enduring
sexual fantasies or preference for rape.
In contrast to some of the other rapist types, there is little offence planning
and any non-sexual aggression is primarily instrumental.
As a result, physical injury to victims is relatively low.
Opportunistic rapists are further distinguished by their level of social
Social competence here refers to “the presence and durability of
interpersonal relationships and the stability of the offender’s employment
and wage-earning history”
Type 1 rapists are higher in social competence and their impulsivity
emerged in adulthood, whereas Type 2 rapists are lower in social
competence and their impulsivity became apparent during adolescence.
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Pervasively angry rapists (Type 3) are characterized by global anger,
which manifests as sexual assault against women as well as non-sexual
aggression against men and women.
These rapists have long histories of aggressive behaviour and engage in
relatively little offence planning.
In contrast to some other types (e.g., opportunistic), they use expressive
aggression in their sexual assaults that results in higher levels of physical
Rapists motivated by sexual gratification are characterized by enduring
sexual or sadistic fantasy or preoccupation.
Compared to the other types, these rapists engage in more offence
They can be divided into two groups based on the presence or absence of
Sadistic rapists are further divided into two groups based on the extent to
which they act on their sadistic fantasies.
overt sadistic rapists (Type 4) act on their sadistic fantasies, evidenced by
sadistic acts and resulting in a high degree of physical injury.
Muted sadistic rapists (Type 5) engage in acts intended to scare and
humiliate the victim (driven by their sadistic fantasies), but inflict
relatively little physical injury.
Non-sadistic offenders are also divided into two groups based on their
level of social competence:
Type 6 is characterized by higher social competence and Type 7 is
characterized by lower social competence.
Vindictive rapists are motivated primarily by misogynistic anger.
In contrast to pervasively angry rapists (Type 3), vindictive rapists’ anger
is not global but rather is focused exclusively on women.
Their intent is to degrade, humiliate, and physically harm their victims.
There is relatively little offence planning.
these rapists use expressive aggression, which results in high physical
These rapists are divided based on their social competence: Type 8 is
lower in social competence, whereas Type 9 is moderate.
Since the initial development of Version 3, new evidence suggests some
structural problems exist with the MTC:R3
these new findings have been incorporated and the typology revised to
create Version 4 of the Massachusetts Treatment Centre: Rapist Typology
The main changes are that the muted sadistic type (Type 5) has been
dropped, some of the types have been repositioned, and the linear structure
has been reconfigured as circular
the MTC:R4 better fits with current empirical evidence.
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4. Researching Initiation Factors:
Two recent meta-analyses provide much needed summaries of existing
Seto and Lalumière (2009) meta-analyzed studies comparing adolescent
male offenders who had committed sex offences to those who had not.
Whitaker et al. (2008) meta-analyzed studies comparing men who had
committed sex offences against children to men who had committed sex
offences against adults (rapists), offenders who had committed non-sexual
offences (non-sex offenders), and men who had not committed any
A third meta-analysis (Jespersen, Lalumière, and Seto 2009) focused
exclusively on differences in childhood abuse and neglect between sex
offenders and various comparison groups.
Childhood Sexual Abuse
Many of the theories we have mentioned posit that sexual victimization in
childhood plays an important role in later sexual offending.
Studies generally find a strong association between childhood sexual
abuse and sexual offending.
Adolescent sex offenders have been found to have experienced
significantly more childhood sexual abuse than adolescent non-sex
adult sex offenders have experienced higher rates of childhood sexual
victimization than adult non-sex offenders and non-offenders
even when information beyond self-reports was used to document
childhood sexual victimization, sex offenders were still found to have
significantly higher rates of victimization than non-sex offenders
These analyses compared reports of abuse based solely on self-report with
information gained in part by other sources of information (in combination
with self-report), such as reports from parents or exclusively from files
from child protection agencies.
Thus the higher rates cannot be accounted for simply by potential biases
associated with self-report.
For example, we might expect some sex offenders to falsely report
childhood sexual abuse after being caught for their offences in an attempt
to gain sympathy or to excuse their offending
Sex offenders against children have significantly higher rates of childhood
sexual victimization than sex offenders against adults.
This is the case for adolescent sex offenders and adult sex offenders
These differences also remained significant and in the same direction
whether abuse was determined exclusively through self-report or other
sources of information
Childhood Physical Abuse
Higher rates of physical abuse in childhood have also been found among
sex offenders compared to non-sex offenders and non-offenders, but the
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differences between groups are not as dramatic as for childhood sexual
Significantly higher rates of physical abuse have been found among
adolescent sex offenders than adolescent non-sex offenders (
A similar significant difference was found for studies on adolescents based
on self-report only, but virtually no difference was found for other sources
Significantly higher rates of physical abuse have also been observed
among adult sex offenders than among non-sex offenders and non-
offenders in one meta-analysis but the higher physical abuse rates among
sex offenders compared to non-sex offenders did not reach statistical
significance in another meta-analysis that included a larger number of
when based on self-report, adult sex offenders had non-significantly
higher rates of childhood physical abuse than non-sex offenders, but non-
significant differences in the opposite direction were found with sources
In contrast to the findings for childhood sexual abuse, sex offenders
against children were less likely to have been physically abused in
childhood than sex offenders against adults.
This is the case (significant) for adult sex offenders and held whether the
comparisons were based only on self-report or other information
non-significant differences in the opposite direction were found with
adolescent sex offenders: adolescent sex offenders against younger
children had slightly higher rates of childhood physical abuse than
adolescent sex offenders against peers or adults.
Neglect and Emotional Abuse
Rates of neglect or emotional abuse were also significantly higher among
adolescent sex offenders than non-sex offenders
The size and the direction of the difference were similar for self-report and
other sources, but were only significant for self-report
Among adult offenders, however, neglect and abuse were non-
significantly less common among sex offenders than non-sex offenders
Sex offenders against children had slightly (but non-significantly) higher
rates of neglect and emotional abuse in childhood than did sex offenders
Attachment and Family Functioning
Despite the higher rates of abuse among sex offenders, it is somewhat
surprising to find that problems with attachment and family functioning do
not differ between child molesters, rapists, and non-sex offenders
when compared to non-offenders, child molesters do have more problems
with attachment and family functioning
Deviant Sexual Interests
sex offenders generally have more deviant sexual interests than non-sex
offenders and non-offenders.
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Adolescent sex offenders also have more deviant sexual interests than
adolescent non-sex offenders (e.g., behaviour, fantasies, and interest in
sexual contact with children or sexual assault).
Adult child molesters have significantly more deviant sexual interests than
adult non-sex offenders and non-offenders but do not differ from rapists
Considering sexual interest in children, in particular, child molesters
showed much more interest in children than non-sex offenders, but this
difference did not reach significance in the meta-analysis
When this finding is considered along with a number of earlier studies not
included in the meta-analysis, there is little question that the average child
molester is more sexually interested in children than the average man who
does not molest children
Meta-analytic reviews indicate that, on average, rapists show greater
sexual arousal to rape than non-rapists
Arousal to non-sexual violence, however, does not appear to distinguish
most rapists from non-rapists but it does distinguish rapists who have
seriously physically injured their victims from those who have done less
serious physical damage
It is generally assumed that the greater arousal to rape observed among
rapists compared to non-rapists is most often the result of reduced
inhibition of sexual arousal in the presence of violence rather than a sexual
preference for rape over consenting sex
Although there are certainly some rapists who prefer rape and are sexually
aroused by the violence and suffering of the victim (e.g., sexual sadism),
most rapists do not seem to differ from non-rapists in the extent to which
they find consenting sex arousing.
What differentiates most rapists is that their sexual arousal is relatively
less diminished when sexual activity is accompanied by violence and
This is consistent with the results from a study comparing the penile
arousal of rapists and non-rapists
penile plethysmography (PPG), involves the physiological measurement
of penile tumescence (erection) during the presentation of various stimuli,
such as descriptions of sexual activity.
Sexual attraction is usually inferred from the amount of arousal in
response to deviant stimuli (e.g., stories about sexual abuse of a child,
rape) relative to non-deviant stimuli (e.g., stories about consenting sex
As measures of sexual interest go, PPG has received much research
attention and is among one of the best measures currently available
Other measures of sexual interest include self-report, viewing time and
more recently, a number of promising cognitive approaches
Although on average differences in sexual arousal to rape have been found
between rapists and non-rapists, there is considerable variability from
study to study.
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Different interpretations of the source of this variability have led to
different conclusions about the role that sexual interests may play in rape.
Some researchers have attributed the variability to the samples examined,
whereas others have attributed it to the stimuli and procedures employed.
With regard to the samples, some researchers have argued that elevated
sexual arousal to rape is only found in groups of rapists with high
proportions of sadistic rapists.
They argue that sexual arousal to rape is only characteristic of a small
number of rapists who are sadistic, but not the majority of rapists.
In contrast, other researchers argue that rapists can be differentiated from
non-rapists when appropriate stimuli and procedures are used.
On average, sex offenders do not appear to be higher on general
antisociality than non-sex offenders.
They are more antisocial than non-offenders.
Specifically, child molesters generally are more angry and hostile than
non-offenders, but slightly less angry and hostile than non-sex offenders
and significantly less angry and hostile than rapists
Child molesters were significantly lower on lifestyle
instability/impulsivity and antisocial personality disorder than non-sex
offenders but did not differ from rapists on antisocial personality disorder
(comparisons were not done for lifestyle instability/impulsivity because
there were too few studies)
In contrast, child molesters were higher than non-offenders on lifestyle
instability/impulsivity (non-significant) and antisocial personality disorder
Experts found that adolescent sex offenders were generally less antisocial
than adolescent non-sex offenders in a number of areas (e.g., fewer prior
involvements with the criminal justice system, lower general antisocial
beliefs, fewer antisocial associations).
adolescent sex offenders did not differ from adolescent non-sex offenders
on antisocial personality traits
experts found adolescent sex offenders against children were less
generally antisocial (e.g., antisocial personality, substance abuse,
antisocial attitudes, antisocial associat