Age and Sexual Recidivism:
A Comparison of Rapists
and Child Molesters
2001 - 01
By
R. Karl Hanson
Department of the Solicitor General Canada
This document is available in French. Ce rapport est
disponible en français sous le titre: L'âge et la récidive
sexuelle - Une comparaison des violeurs et des agresseurs
d'enfants
Public Works and Government Services Canada
Cat. No.: JS42-96/2001
ISBN: 0-662-65737-3
Author note
The views expressed are those of the author and do not
necessarily reflect those of the Portfolio of the Solicitor
General of Canada. I would like to thank Marnie Rice, Grant
Harris, Jean Proulx, Larry Motiuk, Marylee Stephenson, John
Reddon, Lea Studer, Janice Marques, Roxanne Lieb and Lin Song
for access to their original data sets.
Table of Contents
Abstract
Age and sexual recidivism: A comparison of
rapists and child molesters
Method
Samples *
Analysis *
Results
Discussion
Deviant sexual interests *
Low self-control *
Opportunity *
An interpretation of the age-recidivism findings *
References
Abstract
This study examined the relationship of age to sexual
recidivism using data from 10 follow-up studies of adult male
sexual offenders (combined sample of 4,673). Rapists were
younger than child molesters and the recidivism risk of
rapists steadily decreased with age. In contrast,
extrafamilial child molesters showed relatively little
reduction in recidivism risk until after the age of 50. The
recidivism rate of intrafamilial child molesters was
generally low (less than 10%), except for the intrafamilial
offenders in the 18 to 24 year old age group, whose
recidivism risk was comparable to that of rapists and
extrafamilial child molesters. The results are discussed in
terms of developmental changes in sexual drive, self-control,
and opportunities to offend.
Age and sexual recidivism: A comparison of
rapists
and child molesters
The public is justifiably concerned about the risk poised by
sexual offenders. Although the observed sexual recidivism
rates are only 10% to 15% after five years (Hanson &
Bussière, 1998), the rates continue to increase gradually
with extended follow-up periods (Hanson, Steffy &
Gauthier, 1993a). Do sexual offenders remain at risk
throughout their life or is there some age limit after which
their risk for recidivism is substantially reduced? How much
of a threat is a 60 year old child molester or a 60 year old
rapist?
The association between age and general criminal behaviour is
well established. Most crimes are committed by young people
and the rate of criminal behaviour gradually decreases with
age. For crimes reported to the police, the most common age
of the offender is late adolescence (16 to 18 years), with
the age of violent offenders being somewhat older than for
non-violent offenders (Gottfredson & Hirshi, 1990).
Longitudinal studies, however, indicate that the rate of
aggressive behaviour actually peaks in the pre-school years
(ages 3-4) and declines steadily thereafter (Tremblay, 2000).
The apparent rise in violent crime during adolescence is
simply the function of a change in community response to
persistent aggressive behaviour. Nagin and Tremblay (1999)
did not find any group of persistently violent boys for whom
the onset of aggression was later than age six.
Less is known about the relationship between age and sexual
crime. Based on data from 179 Canadian police departments,
81% of accused sexual offenders were 18 years of age or older
(Canadian Centre for Justice Statistics, 1999). On average,
accused sexual offenders are substantially older than other
offenders and slightly older than the general population. The
age distribution for sexual offenders is markedly bimodal,
however, with the largest peak at age 13, a dip in the early
twenties, and a second peak in the mid to late thirties
(Canadian Centre for Justice Statistics, 1999). The reason
for the bimodal distribution is unknown but it does suggest
that there may be a qualitative difference between adolescent
and adult sexual offenders. The peak at age 13 may be
attributed to generally antisocial, aggressive youth becoming
sexually active. The peak in the late thirties may be related
to increased opportunities for certain types of sexual
offences during these years (e.g., father-daughter incest,
child molestation).
Age differences are also noted among adult sexual offenders.
It has long been observed that those who victimise adult
women (rapists) tend to be younger than those who target
children (child molesters) (Apfelberg, Sugar & Pfeffer,
1944; West, 1983).
The distribution of the age of accused sexual offenders does
not necessarily indicate their relative recidivism risk.
Although there may be few sexual offenders over the age of
50, the older offenders may be more (or less) persistent than
younger sexual offenders. Hanson and Bussière's (1998) review
of 21 follow-up studies (n = 6,969) found an overall negative
relationship between age and risk for sexual recidivism
(average r = -.13). The relationship, however, was not large,
and there was considerable variability across studies.
It is possible that the relationship between age and sexual
recidivism is different for different types of sexual
offenders. Of all the sexual offenders, rapists show the
greatest similarity to non-sexual criminals (West, 1983).
Rapists are likely to have non-sexual criminal histories and
are more likely than child molesters to recidivate with
non-sexual crime (Hanson & Bussière, 1998). Consequently,
it is likely that the recidivism rate of rapists steadily
decreases with age.
The extent to which the recidivism rates of child molesters
decreases with age is unknown. Given that most antisocial
behaviour declines with age, it is likely that the sexual
recidivism rates of child molesters would similarly decline.
It is possible, however, that the decline could be minimal.
Extrafamilial child molesters are the sexual offenders most
likely to have deviant sexual preferences (Marshall, 1997).
The presence of such deviant sexual preferences may
contribute to a sustained level of risk well into late
adulthood.
Child molesters who only target intrafamilial victims (incest
offenders) have consistently lower recidivism risk than other
sexual offenders (Hanson & Bussière, 1998). Although
incest offenders would be expected to be older than other
child molesters (it takes time for one's own children to
mature), it is unclear whether the recidivism rates of incest
offenders should substantially decrease with age. The
disclosure process for the index offence may block access to
the children in their current family, but the subsequent
arrival of grandchildren may provide new opportunities.
In order to examine the relationship between age and sexual
recidivism, secondary analyses were conducted on 10 samples
of sexual offenders (total sample of 4,673). These samples
were drawn from diverse settings in Canada (k = 7), the
United States (k = 2) and the United Kingdom (one sample).
Method
Samples
An overview of the samples can be found in Table 1. All the
offenders were released from institutions with the exception
of about half of the offenders from the Washington SSOSA
sample, who received community sentences. Racial ethnicity
was not recorded for most samples, but given the demographics
of the provinces, states and countries from which they were
selected, the offenders can be expected to be predominantly
white. The sample sizes are slightly smaller than the numbers
reported in the original studies because the current samples
were restricted to those for whom information was available
on both age and sexual recidivism. All offenders were adult
males (18 years old or older at time of release).
Canadian Federal Recidivism Study - 1983/1984 Releases
(Bonta & Hanson, 1995a; see also Bonta & Hanson,
1995b). This study examined the 316 sexual offenders included
in the complete sample of 3,180 federal offenders released by
the Correctional Service of Canada (CSC) in the fiscal year
1983/1984. Sexual offenders were defined as those who were
released following any sexual conviction. Recidivism
information was collected in 1994 using national criminal
history records maintained by the Royal Canadian Mounted
Police (RCMP).
Canadian Federal 1991 to 1994 Releases (Motiuk, 1995;
see also Motiuk & Brown, 1993; Motiuk & Brown, 1996).
This study followed a group of sexual offenders released by
CSC between 1991 and 1994. The offenders in this group were
those who were reviewed in 1991 (see Motiuk & Porporino,
1993) while they were still incarcerated. Follow-up
information was coded from 1994 RCMP records.
Canadian Federal - Pacific Region (CS/RESORS
Consulting, 1991; Hanson, Broom & Stephenson, 2001). This
study followed sexual offenders released in British Columbia
between 1976 and 1992. The original aim of the study was to
compare offenders who received mandatory community
counselling (n = 401) and those released in earlier years
without the
Table 1
Study characteristics.
Sample
|
Total
Sample Size
|
Age (SD)
|
Offender Type
Rape/EX/IN (%)
|
Sample Size for Type
|
Average Years of Follow-up
|
Sexual Recid. Rate
|
Recidivism Criteria
|
Canadian Federal
1983/84 releases
|
315
|
31 (8.7)
|
-- / -- / --
|
0
|
10
|
19.7
|
Convictions
|
Canadian Federal
1991 to 1994 releases
|
241
|
37 (11)
|
53 / 19 / 28
|
208
|
2
|
7.1
|
Charges
|
Canadian Federal
Pacific Region
|
689
|
38 (11)
|
36 / 30 / 33
|
362
|
11
|
24.7
|
Charges
|
Millbrook, Ontario
|
186
|
33 (10)
|
00 / 82 / 18
|
186
|
3
|
35.5
|
Convictions
|
Institut Philippe Pinel
|
363
|
36 (11)
|
30 / 43 / 27
|
349
|
4
|
16.3
|
Convictions
|
Alberta Hospital Edmonton
|
363
|
36 (10)
|
27 / 27 / 46
|
363
|
5
|
5.5
|
Convictions
|
SOTEP (California)
|
1,137
|
38 (8.9)
|
29 / 40 / 31
|
1,130
|
4
|
13.3
|
Charges
|
Oak Ridge
Penetanguishene, Ontario
|
263
|
31 (9.4)
|
52 / 26 / 22
|
246
|
10
|
36.1
|
Charges/
readmissions
|
HM Prison Service (UK)
|
529
|
36 (12)
|
53 / 32 / 15
|
325
|
16
|
25.7
|
Convictions
|
Washington State SSOSA
|
587
|
36 (13)
|
10 / 41 / 49
|
582
|
5
|
7.5
|
Charges
|
Note: EX = Extrafamilial child molesters; IN = Intrafamilial
child molesters
benefit of this post-release program (n = 288). Offenders
released in the 1983/84 fiscal year (n = 38) were removed
from this sample to avoid overlap with the other CSC cohort
described above. Recidivism information was coded in 2000
from RCMP records.
Alberta Hospital Edmonton - Phoenix Program. (Reddon,
1996; see also Studer, Reddon, Roper & Estrada, 1996).
The sexual offenders in this study were drawn from those
treated at the Phoenix (Alberta Hospital Edmonton) program
between 1987 and 1994. The Phoenix program is an eclectic
inpatient treatment program that receives many of its
referrals from federal correctional facilities. Recidivism
information was collected in 1995 using RCMP records.
California's Sex Offender Treatment and Evaluation Project
(SOTEP). (Marques & Day, 1996; see also Marques, Day,
Nelson & West, 1993; Marques, Nelson, West & Day,
1994). The primary aim of this ongoing study is to examine
the efficacy of treatment. The sample used in the current
study included sexual offenders randomly assigned to
treatment (n = 172), matched volunteer controls, treatment
refusers, as well as a general sample of sexual offenders
from the California correctional system (total sample of
1,137). Men who had offended only against their biological
children were not included. Subjects were admitted to this
study between 1985 and 1995; follow-up information was
collected in 1995 based on local and national criminal
records, as well as local police and probation reports.
Institut Philippe Pinel (Montreal). (Proulx, Pellerin,
McKibben, Aubut & Ouimet, 1995; see also Proulx,
Pellerin, McKibben, Aubut & Ouimet, 1997; Pellerin et
al., 1996). This study focused on sexual offenders treated at
a maximum security psychiatric facility between 1978 and
1993. The Institut Philippe Pinel in Montreal provides long
term (1-3 years) treatment for sexual offenders referred from
both the mental health and correctional systems. Recidivism
information was collected in 1994 from RCMP records.
Millbrook Recidivism Study (Hanson, Steffy &
Gauthier, 1993b; see also Hanson, Scott & Steffy, 1995;
Hanson, Steffy & Gauthier, 1992; Hanson et al., 1993a).
This study collected long-term recidivism information (15-30
years) for child molesters released between 1958 and 1974
from Millbrook Correctional Centre, a maximum security
provincial correctional facility located in Ontario, Canada.
About half of the sample went through a brief treatment
program. Recidivism information was coded from RCMP records
in 1989 and 1991.
Oak Ridge Division of the Penetanguishene Mental Health
Centre. (Rice & Harris, 1996; see also Quinsey, Rice
& Harris, 1995; Rice & Harris, 1997; Rice, Harris
& Quinsey, 1990; Rice, Quinsey & Harris, 1991). The
Oak Ridge study followed sexual offenders referred between
1972 and 1993 for treatment and/or assessment to a maximum
security mental health centre located in Ontario, Canada. The
majority of the referrals came from the mental health systems
or the courts (e.g., pretrial fitness examinations), with a
minority of cases coming from provincial or federal
corrections. Follow-up information was based on RCMP records
as well as mental health records (i.e., new admissions for
sexual offenses, whether or not new charges were laid).
Her Majesty's Prison Service (UK). (Thornton, 1997).
The study provided a 16 year follow-up of all sexual
offenders released from Her Majesty's Prison Service (England
and Wales) in 1979 (n = 573). Recidivism information was
based on Home Office records collected in 1995. Very few of
the offenders in this sample would have received specialised
sexual offender treatment.
Washington SSOSA. (Berliner, Schram, Miller &
Milloy, 1995; Song & Lieb, 1995). This data set was
created to evaluate Washington State's Special Sex Offender
Sentencing Alternative (SSOSA), which allows judges to
sentence sex offenders to community treatment. To be eligible
for SSOSA, offenders must be facing their first felony
conviction for sexual crimes other than first or second
degree rape. The sample consisted of 287 offenders who
received SSOSA and 300 who were statutorily eligible for
SSOSA but did not receive it. The majority of the sample was
White (85%). Offenders were convicted between January 1985
and June 1986, with follow-up data collected in December,
1990.
Analysis
The analyses were conducted on a data set that combined the
above samples. Age was measured at the time of release from
institution, except for the Washington SSOSA sample where age
was measured at time of sentencing. Sexual recidivism was
measured using the definitions used in the original reports,
which, in most cases was either charges (k = 4) or
convictions (k = 5). The Oak Ridge sample also included
readmissions to psychiatric facilities among their recidivism
criteria.
Preliminary analyses were conducted that examined the
association between age and recidivism in each sample. The
meta-analysis of the individual samples found the same
pattern of results as the analysis of total sample. For
simplicity, only the results from the total sample are
presented.
The primary statistical procedure used to measure the
association between age and sexual recidivism was logistic
regression (Neter, Kutner, Nachtsheim & Wasserman, 1996).
Logistic regression is preferable to ordinary least square
regression when the outcome variables is dichotomous. In
comparison to correlation coefficients, the logistic
regression coefficients are less influenced by recidivism
base rates and variability in the predictor variables. One
way to interpret logistic regression coefficient is as the
rate of change in recidivism rates for each year age
increase; more specifically, eB is an odds ratio.
For example, if B was -.04, the odds ratio would be
(2.714)(-.04) = .96. This value of .96 can be
interpreted to mean that if Jack is one year older than
Frank, Jack's recidivism rate would be expected to be 96% of
Frank's expected recidivism rate (a 4% reduction). For small
values of B, the percentage change in recidivism rates is
approximately equal to the absolute value of B (i.e., B =
-.04 corresponds to a 4% reduction; B = .10 corresponds to a
10.5% increase).
Curvilinear effects can be tested by entering the square of
the predictor variable (Y2) after entering the
predictor variable (Y). Readers should be cautioned, however,
that when Y and Y2 are considered simultaneously,
the value of their respective regression coefficients (and
their significant tests) can be influenced by arbitrary
features of scaling. Consequently, the resulting regression
coefficients do not provide a test of the relative magnitude
of the linear and curvilinear effects. The regression
coefficients for the curve components are presented,
nonetheless, to indicate the direction of any potential
curvilinear effects.
Results
The combined sample included 4,673 sexual offenders. Based on
the offenders' predominant victim choice, the sample was
divided into those who sexually victimised adult women
(Rapists, n = 1,133), child molesters who victimise any
unrelated children (Extrafamilial child molesters, n =
1,411), and child molesters who victimised only related
children (Incest offenders, n = 1,207). Excluded from the
classification were 47 offenders who victimised both adult
women and unrelated children and 875 offenders for whom
victim information was not available. The classification,
however, was based on limited information and the cross-over
between victim types would likely be greater than that
implied by the current classification.
As can be seen in Figure 1, the rapists (mean = 32.1, SD =
8.9) were younger than the extrafamilial child molesters
(mean = 37.1, SD = 11.5) and incest offenders (mean = 38.9,
SD = 9.9). Due to the large sample sizes, differences between
all the groups were statistically significant at p < .001
even though the average age difference between the two child
molesters groups was only 1.8 years.
Figure 1
The sexual recidivism rate for the total sample was 17.5%
(820/4,673). In the total sample, the recidivism rate
declined steadily with age (logistic regression, B = -.036,
SD = .004, p < .001). The association was linear; the
addition of a curvilinear component did not significantly
improve the fit of the regression line (chi-square change =
0.18, df = 1, p > .50). The correlation between age and
sexual recidivism was -.13 (p < .001) and the ROC area was
.60 (95% confidence interval of .58 to .62).
The groups recidivated at different rates (logistic
chi-square change = 57.91, df = 2, p < .001), with incest
offender recidivating less often (8.4%) than rapists (17.1%)
and extrafamilial child molesters (19.5%). Without
controlling for age, the difference in recidivism rates for
the rapist and extrafamilial child molesters was not
statistically significant (logistic chi-square = 2.21, df =
1, p > .10). Controlling for age, however, resulted in a
significant difference between the extrafamilial child
molesters and rapists (logistic chi-square = 7.71, df = 1,
p < .005), with the child molesters recidivating more
often than the rapists. The incest offenders had
significantly lower recidivism rates in all the comparisons
(p < .001).
Even though the effect of age was linear in the total sample,
the relationship with age was different for the rapists,
extrafamilial child molesters and incest offenders (see
Figure 2; interaction between groups and age2
[age-squared]: logistic chi-square change = 6.81, df = 2,
p < .05). The separate analyses for the three groups are
displayed in Table 2. The recidivism rate for rapists
steadily decreased with age (logistic B = -.040, SD = .010).
In contrast, the highest risk age period for extrafamilial
child molesters was not between the years of 18 to 24, but
between the ages of 25 and 35. The recidivism rate of the
extrafamilial child molesters showed relatively little
decline until after age 50.
Incest offenders showed a different pattern. The recidivism
rate for the incest offenders was generally low (less than
10%) except for the incest offenders in the 18 to 24 age
group who showed a much higher recidivism rate (30.7%).
There were very few recidivists among the sexual offenders
released after age 60 (5/131 or 3.8%). The "over-60"
recidivists included 2 extrafamilial child molesters (2/45 or
4.4%) and 3 unclassified offenders (3/37 or 8.1%). None of
the incest offenders (n = 39) or rapists (n = 10) who were
over 60 at time of release recidivated. The oldest recidivist
in the sample was released at age 72 and was reconvicted for
a sexual offence the following year.
Figure 2
Table 2
The relationship between age (years) and sexual recidivism
(1 = yes; 0 = no).
Sample
|
Sample size
|
Step
|
Logistic regression coefficients
|
x 2 change
|
x 2 model
|
|
|
|
intercept
|
linear
|
curvilinear
|
|
|
Rapists
|
1,133
|
1
|
-.334
(.319)
|
-.040
(.010)
|
-
|
-
|
16.82***
|
|
|
2
|
-.585
(.995)
|
-.024
(.060)
|
.00023
(.00088)
|
.073
|
17.37***
|
Extrafamilial
Child Molesters
|
1,411
|
1
|
-.411
(.232)
|
-.028
(.006)
|
-
|
-
|
20.65***
|
|
|
2
|
-2.344
(.778)
|
.082
(.043)
|
-.00144
(.00056)
|
7.44**
|
27.98***
|
Incest Offenders
|
1,207
|
1
|
-.069
(.448)
|
-.064
(.013)
|
-
|
-
|
28.88***
|
|
|
2
|
1.359
(1.154)
|
-.144
(.061)
|
.00108
(.00079)
|
1.59
|
30.38***
|
Total
|
4,673
|
1
|
-.324
(.140)
|
-.035
(.004)
|
-
|
-
|
84.68***
|
|
|
2
|
-.489
(.410)
|
-.026
(.023)
|
.00013
(.00030)
|
.19
|
84.87***
|
*p < .05; **p < .01, ***p < .001.
Note: Standard deviations in parentheses.
Discussion
As with other criminal behaviour, the rate of sexual
offending decreased with age. The rate of decline was rather
gradual, however, and there were significant differences
between types of sexual offenders. Rapists were younger than
other sexual offenders (45% less than 30) and their
recidivism risk steadily decreased with age. Extrafamilial
child showed little decline in their recidivism risk until
after the age of 50. The highest risk period for
extrafamilial child molesters was between the ages of 25 and
35. In contrast, the young (18-24 year old) incest offenders
were substantially higher risk than incest offenders from
other age groups.
The average recidivism rate for the incest offenders (8%) was
lower than the average recidivism risk for extrafamilial
child molesters (19%) and rapists (17%). Although the
recidivism rates for extrafamilial child molesters and
rapists were similar, extrafamilial child molesters were, on
average, older than rapists. When age was controlled, the
extrafamilial child molesters were at significantly higher
risk for sexual recidivism than the rapists.
Among the various factors linked to sexual offending, the
three broad factors most relevant to the current study are
deviant sexual interests (motivation), opportunity, and low
self-control. The distribution of these factors across
offender types can help explain the age distribution of the
offenders and the variation in their recidivism rates.
Deviant sexual interests
Although all sexual offenders engage in sexually deviant
behaviour, most do not have an enduring preference for
illegal sexual activities. Sexual preferences have some
degree of elasticity, such that men typically prefer
consensual activities with adult females, but they show some
arousal to less physically mature females (Freund &
Blanchard, 1989) and to depictions of forced sex (Eccles,
Marshall & Barbaree, 1994). Offenders may act on these
less-than-preferred sexual objects/activities for any number
of reasons, including peer pressure (e.g., Kanin, 1967),
impulsivity, and opportunity.
Deviant sexual interests are more common among extrafamilial
child molesters than incest offenders (Marshall, 1997). It is
difficult to directly compare the rate of deviant sexual
interest among rapists with the rate among child molesters.
Sexual interests exist on a continuum and it is not clear
what level of sexual interest in violence corresponds to an
equivalently deviant level of sexual interest in children.
Nevertheless, rapists, on average, sexually respond more to
violent erotic stimuli than to depictions of consensual
sexual activities (Lalumière & Quinsey, 1994), suggesting
that a significant proportion of rapists hold deviant sexual
interests. Deviant sexual interests are likely to be more
common among rapists than among incest offenders; whether
rapists are more or less sexually deviant than extrafamilial
child molesters is unknown.
Previous research has suggested that deviant sexual interest
is an important risk factors for sexual recidivism (Hanson
& Bussière, 1998). To the extent that deviant sexual
interests are an integral part of an offender's sexual life,
then the persistence of sexual offending should mirror the
persistence of the offender's sexual drive.
Research on normal populations has found that male sexual
drive declines steadily with age, although the reduction is
relatively limited until after age 50 (Kinsey, Pomeroy &
Martin, 1948; Panser et al., 1995; Trocki, 1992). Fewer than
1% of men aged 40-49 reported "no sex drive" compared to 26%
of men over the age of 70 (Panser et al., 1995). Among the
factors than can contribute to reduced sexual drive are
disease and age related decreases in testosterone (Gray,
Feldman, McKinlay & Longcope, 1991).
Low self-control
The second major factor associated with sexual offending is
low self-control or criminal lifestyle. Low self-control
refers to the tendency to respond impulsively to short-term
temptation, have little consideration for future
consequences, and engage in high risk behaviours, such as
drinking, driving fast, and sexual promiscuity. The
association between low self-control and criminal behaviour
is sufficiently strong that Gottfredson and Hirshi (1990)
consider it to be the cause of crime. It is not
uncommon for researchers to include measures of antisocial
behaviour in their definitions of impulsivity or low
constraint (e.g., Prentky, Knight, Lee & Cerce, 1995;
Wright, Caspi, Moffitt & Silva, 1999).
Self-control increases dramatically from childhood to
adulthood. The extent to which it continues to develop in the
adult years in less well established. Gottfredson and Hirschi
(1990) believe that an individual's level of self-control
changes little after it is initial formed in the family of
origin. However, the age related decline in almost all
impulsive, risky behaviour (e.g., fast driving, substance
abuse, theft, assault) suggests that self-control and
constraint continue to develop well into the adult years.
Previous research with sexual offenders has found that
impulsivity and crime lifestyle are related to the risk of
sexual recidivism (Hanson & Bussière, 1998; Prentky et
al., 1995). Low self-control is more common among rapists
than child molesters. Rapists share many of the features of
lifestyle instablility found among general offenders (West,
1983), and are more likely to recidivate with non-sexual
crime than are child molesters (Hanson & Bussière, 1998).
The research has yet to establish whether incest offenders
and extrafamilial child molesters differ in lifestyle
instability. Miner and Dwyer (1997) found that incest
offenders reported less problems with immediate gratification
than extrafamilial child molesters, whereas Symbaluk (1998)
found the reverse: incest offenders had more problems with
low self-control than extrafamilial child molesters. The
incest offenders and extrafamilial child molesters from
Firestone et al.'s samples (1999, 2000) displayed similar
levels of self-control on indicators such as low education,
substance abuse, aggression and psychopathy.
Opportunity
The third factor related to sexual offending is opportunity.
Unlike problems with self-control, which should diminish in
early adulthood, and deviant sexual drives, which should
diminish in later adulthood, the opportunities for child
molesting should increase in middle adulthood. Most child
molesters exploit a relationship of trust with a known or
related victim. The opportunities for establishing
relationships with children are greatest between the late
twenties and mid forties. It is during this age period that
men are most likely to have their own children, and to
associate with friends and family who have children.
The opportunities for rape, in contrast, should gradually
decrease with age. Most rape victims are young women known to
the offender. People tend to associated with people their
same age; consequently, as men age, they would be expected to
encounter fewer potential victims, and fewer circumstances in
which rape is an easily available option (e.g., bars, college
parties).
An interpretation of the age-recidivism
findings
The three factors of sexual deviancy, self-control, and
opportunity are consistent with the age-recidivism findings
for the rapists and extrafamilial child molesters. For the
rapists, all three factors should decline with age.
Self-control should increase in young adulthood, deviant
sexual drives should decrease in late adulthood, and the
opportunities should gradually decline throughout. If these
factors are indeed important, then it is not surprising that
most rapists are young and that their recidivism risk
steadily declines with age.
For extrafamilial child molesters, competing factors may be
influencing recidivism risk during early to middle adulthood.
Self-control should improve during the transition from the
twenties to the thirties, but the opportunities for child
molesting should increase. It is not until late adulthood
that the opportunities for relationships with children
decline, and, combined with a reduction in sexual drive,
contribute to a reduction in recidivism risk. This theory is
consistent with the findings that child molesters are older
than rapists, and that the recidivism rate of extrafamilial
child molesters is relatively constant during the early and
middle years of adulthood.
The theory outlined above provides only a partial fit to the
finding for incest offenders. The peak frequency of incest
offenders in the late thirties is consistent with increased
opportunity for incestuous abuse during middle adulthood. As
well, the low recidivism rates of incest offenders is
consistent with their relatively low levels of deviant sexual
interests (compared to extrafamilial child molesters),
moderately stable lifestyles (compared to rapists), and
reduced opportunity compared to other sexual offenders (their
available victim pool is restricted to family members).
The high recidivism rates of the young incest offenders,
however, was unexpected. There were relatively few incest
offenders in the 18 to 24 year age group (n = 75), but their
recidivism rate was among the highest for any offender type
(31%). These findings suggest that the young incest offenders
may be a group distinct from the typical father/daughter
incest offender. In the current study, the victims of the
younger incest offenders were unknown, but were unlikely to
be their own children. Instead, they most likely victimised
their siblings, step-siblings or nieces/nephews. The extent
to which these young incest offenders resemble other sexual
offenders (e.g., rapists, extrafamilial child molesters)
remains to be explored. All the offenders in the sample,
however, would have been expected to have used overt force or
selected a victim much younger than themselves. Relatively
consensual sexual behaviour among siblings rarely invokes the
serious criminal justice sanctions that were imposed on most
offenders in this study.
There were few sexual offenders of any type in the advanced
age categories (11% of the total sample was over 50), and
their recidivism rates were generally low (< 10%). This
decline in late adulthood can be attributed to the confluence
of decreasing sexual drive and decreasing opportunity.
Perhaps the most salient factor for the oldest age groups,
however, would be increasing ill health and eventual death.
Medical records were not available for any of the samples
analysed in this study; consequently, research has yet to
examine the extent to which reductions in sexual recidivism
risk should be expected for older offenders who remain in
good health. In the normal population, decreases in sexual
interest and activities in later years are closely linked to
concomitant illness (Panser et al., 1995).
In summary, this study found that the recidivism risk for
sexual offenders decreased with age, but the overall effect
was not large and the pattern of decline was different for
rapists, extrafamilial child molesters and incest offenders.
Extrafamilial child molesters show relatively little decline
in their recidivism risk until after the age of fifty. Sexual
offenders released after the age of 60 showed very low
recidivism rates (3.8%).
Although the factors of deviant sexual drive, low
self-control and opportunity provide a plausible explanation
for the findings, other explanations need to be considered.
All of the data was cross-sectional rather than longitudinal;
consequently, an apparent age-related decline in sexual
offending could be explained by cohort effects. Given that
there are strong cohort effects in sexual behaviour (e.g.,
almost all [95%] of those born after 1964 had intercourse
prior to age 18 compared to half [51%] of those born before
1949; Trocki, 1992), it is possible that there are also
cohort effects in the rates of sexual offending.
Another consideration is that offenders' ages were measured
at time of release and not the onset of offending.
Consequently, the finding that child molesters were older
than rapists could be attributed to a greater delay in the
detection and prosecution of offences against children than
for offences against adults.
Much of the age decline in sexual offending could also be
attributed to a simple learning effect. With experience, men
can learn that sex offending is not an effective route to
happiness, or, more disturbingly, they can learn new and
better ways to avoid detection. Disentangling these various
explanation requires, of course, further research.
References
Apfelberg, B., Sugar, C., & Pfeffer, A. Z. (1944). A
psychiatric study of 250 sex offenders. American Journal
of Psychiatry, 100, 762-770.
Berliner, L., Schram, D., Miller, L. L., & Milloy, C. D.
(1995). A sentencing alternative for sex offenders: A study
of decision making and recidivism. Journal of
Interpersonal Violence, 10, 487-502.
Bonta, J., & Hanson, R. K. (1995a). [10-year recidivism
of Canadian federal offenders]. Unpublished raw data.
Bonta, J., & Hanson, R. K. (1995b, August). Violent
recidivism of men released from prison. Paper presented
at the 103rd annual convention of the American Psychological
Association: New York.
Canadian Centre for Justice Statistics. (1999). Sex
offenders. Juristat Catalogue no. 85 -002-XIE Vol. 19,
no. 3. Ottawa: Statistics Canada.
CS/RESORS Consulting. (1991). An evaluation of community
sex offender programs in the Pacific Region. Report
presented to the Correctional Service of Canada Regional
Headquarters (Contract no. 21803-0-A602/01-XSB). Vancouver,
B.C.: Author.
Eccles, A., Marshall, W. L., & Barbaree, H. E. (1994).
Differentiating rapists and non-offenders using the rape
index. Behavior Research and Therapy, 32, 539-546.
Firestone, P., Bradford, J. M., McCoy, M., Greenberg, D. M.,
Curry, S., & Larose, M. R. (2000). Prediction of
recidivism in extrafamilial child molesters based on
court-related assessments. Sexual Abuse: A Journal of
Research and Treatment, 12, 203-221.
Firestone, P., Bradford, J. M., McCoy, M., Greenberg, D. M.,
Larose, M. R., & Curry, S. (1999). Prediction of
recidivism in incest offenders. Journal of Interpersonal
Violence, 14, 511 -531.
Freund, K., & Blanchard, R. (1989). Phallometric
diagnosis of pedophilia. Journal of Consulting and
Clinical Psychology, 57, 100-105.
Gottfredson, M. R., & Hirschi, T. (1990). A general
theory of crime. Stanford, CA: Stanford University Press.
Gray, A., Feldman, H. A., McKinlay, J. B., & Longcope, C.
(1991). Age, disease, and changing sex hormone levels in
middle-aged men: Results of the Massachusetts Male Aging
Study. Journal of Clinical Endocrinology and Metabolism,
73, 1016-1025.
Hanson, R. K., Broom, I., & Stephenson, M. (2000).
[Updated recidivism information on sexual offenders in the
CSC Pacific Region]. Unpublished raw data.
Hanson, R. K., & Bussière, M. T. (1998). Predicting
relapse: A meta-analysis of sexual offender recidivism
studies. Journal of Consulting and Clinical Psychology, 66
(2), 348-362.
Hanson, R. K., Scott, H., & Steffy, R. A. (1995). A
comparison of child molesters and non-sexual criminals: Risk
predictors and long-term recidivism. Journal of Research
in Crime and Delinquency, 32(3), 325-337.
Hanson, R. K., Steffy, R. A., & Gauthier, R. (1992).
Long-term follow-up of child molesters: Risk prediction
and treatment outcome. (User Report No. 1992-02.) Ottawa:
Corrections Branch, Ministry of the Solicitor General of
Canada.
Hanson, R. K., Steffy, R. A., & Gauthier, R. (1993a).
Long-term recidivism of child molesters. Journal of
Consulting and Clinical Psychology, 61, 646-652.
Hanson, R. K., Steffy, R. A., & Gauthier, R.
(1993b). [Long-term recidivism of child molesters].
Unpublished raw data.
Kanin, E. J. (1967). Reference groups and sex conduct norm
violations. The Sociological Quarterly, 8, 495-504.
Kinsey, A. C., Pomeroy, W. B., & Martin, C. E. (1948).
Sexual behavior in the human male. Philadelphia: W. B.
Saunders.
Lalumière, M. L., & Quinsey, V. L. (1994). The
discriminability of rapists from non-sex offenders using
phallometric measures: A meta-analysis. Criminal Justice
and Behavior, 21, 150-175.
Marques, J. K., & Day, D. M. (1996). [SOTEP follow-up
data for 1995]. Unpublished raw data.
Marques, J. K., Day, D. M., Nelson, C., & West, M. A.
(1993). Effects of cognitive-behavioral treatment on sex
offenders' recidivism: Preliminary results of a longitudinal
study. Criminal Justice and Behavior, 21, 28-54.
Marques, J. K., Nelson, C., West, M. A., & Day, D. M.
(1994). The relationship between treatment goals and
recidivism among child molesters. Behaviour Research and
Therapy, 32, 577-588.
Marshall, W. L. (1997). Pedophilia: Psychopathology and
theory. In D. R. Laws and W. O'Donohue (Eds.), Sexual
deviance: Theory, assessment and treatment (pp. 152-174).
New York: Guilford.
Miner, M. H., & Dwyer, S. M. (1997). The psychosocial
development of sex offenders: Differences between
exhibitionists, child molesters, and incest offenders.
International Journal of Offender Therapy and Comparative
Criminology, 41, 36-44.
Motiuk, L. L. (1995). [Sex offender recidivism information
for case load and new releases: March, 1991 to July, 1994].
Unpublished raw data.
Motiuk, L. L., & Brown, S. L. (1993). Survival time
until suspension for sex offenders on conditional
release. (Research Report No. R-31). Ottawa, Canada:
Correctional Service of Canada.
Motiuk, L. L., & Brown, S. L. (1996). Factors related
to recidivism among released federal sex offenders.
(Research Report No. R-49). Ottawa, Canada: Correctional
Service of Canada.
Motiuk, L. L., & Porporino, F. J. (1993). An
examination of sex offender case histories in federal
corrections. (Research Report No. R-30). Ottawa, Canada:
Correctional Service of Canada.
Nagin, D., & Tremblay, R. E. (1999). Trajectories of
boys' physical aggression, opposition, and hyperactivity on
the path to physically violent and non violent juvenile
delinquency. Child Development, 70, 1181-1196.
Neter, J., Kutner, M. H., Nachtsheim, C. J., & Wasserman,
W. (1996). Applied linear statistical models
(4th ed.). Chicago: Irwin.
Panser, L. A., Rhodes, T., Girman, C. J., Guess, H. A.,
Chute, C. G., Oesterling, J. E., Lieber, M. M., &
Jacobsen, S. J. (1995). Sexual function of men ages 40 to 79
years: The Olmsted County study of urinary symptoms and
health status among men. Journal of the American
Geriatrics Society, 43, 1107-1111.
Pellerin, B., Proulx, J., Ouimet, M., Paradis, Y., McKibben,
A., & Aubut, J. (1996). Étude de la récidive
post-traitement chez des agresseurs sexuels judiciarisés.
Criminologie, 29, 85-108.
Prentky, R. A., Knight, R. A., Lee, A. F., & Cerce, D. D.
(1995). Predictive validity of lifestyle impulsivity for
rapists. Criminal Justice and Behavior, 22, 106-128.
Proulx, J., Pellerin, B., McKibben, A., Aubut, J., &
Ouimet, M. (1997). Static and dynamic predictors of
recidivism in sexual offenders. Sexual Abuse, 9, 7-28.
Proulx, J., Pellerin, B., McKibben, A., Aubut, J., &
Ouimet, M. (1995). [Static and dynamic predictors of
recidivism in sexual aggressors]. Unpublished raw data.
Quinsey, V. L., Rice, M. E., & Harris, G. T. (1995).
Actuarial prediction of sexual recidivism. Journal of
Interpersonal Violence, 10(1), 85-105.
Reddon, J. R. (1996). [Phoenix Program for Sex Offender
Treatment: An evaluation update with recidivism data obtained
in September, 1995]. Unpublished raw data.
Rice, M. E., & Harris, G. T. (1996). [Recidivism
information on 288 sexual offenders released from the
Oakridge Mental Health Centre, Penetanguishene, Ontario].
Unpublished raw data.
Rice, M. E., & Harris, G. T. (1997). Cross-validation and
extension of the Violence Risk Appraisal Guide for child
molesters and rapists. Law and Human Behavior, 21,
231-241.
Rice, M. E., Harris, G. T., & Quinsey, V. L. (1990). A
follow-up of rapists assessed in a maximum-security
psychiatric facility. Journal of Interpersonal Violence,
5(4), 435-448.
Rice, M. E., Quinsey, V. L., & Harris, G. T. (1991).
Sexual recidivism among child molesters released from a
maximum security institution. Journal of Consulting and
Clinical Psychology, 59, 381-386.
Song, L., & Lieb, R. (1995). Washington State sex
offenders: Overview of recidivism studies. Olympia, WA:
Washington State Institute for Public Policy.
Studer, L. H., Reddon, J. R., Roper, V., & Estrada, L.
(1996). Phoenix: An inpatient treatment program for sex
offenders. Journal of Offender Rehabilitation, 23,
91-97.
Symbaluk, D. G. (1998). An application of the general
theory of crime to sex offenders. Unpublished doctoral
dissertation. University of Alberta, Edmonton, Alberta.
Thornton, D. (1997). [A 16-year follow-up of 563 sexual
offenders released from HM Prison Service in 1979.]
Unpublished raw data.
Tremblay, R. E. (2000). The origins of youth violence.
Isuma: Canadian Journal of Policy Research/Revue
canadienne de recherche sur les politiques, 1(2), 19-24.
Trocki, K. F. (1992). Patterns of sexuality and risky
sexuality in the general population of a California county.
Journal of Sex Research, 29(1), 85-94.
West, D. J. (1983). Sex offenses and offending. In M. Tonry
& N. Morris (Eds.), Crime and justice: An annual
review of research (pp. 183-233). Chicago: University of
Chicago Press.
Wright, B. E., Caspi, A., Moffitt, T. E., & Silva, P. A.
(1999). Low self-control, social bonds, and crime: Social
causation, social selection, or both? Criminology, 37,
479-514.
|