There are no fully standardized phallometric assess-
ment packages, but several procedural, instrumenta-
tion, and interpretation issues have been worked out.
Most important, validity is enhanced with relative
measurement—for example, comparing each man’s
greatest mean response to a prepubescent child cate-
gory with his response to his largest adult category or
comparing his largest response to a violent category
with his mean response to consenting sex. Responses
to a single stimulus or category are much less infor-
mative. Validity is also improved by having multiple
stimuli in each category, using ipsative scoring to
remove between-subject variability in overall response
magnitude, using stimuli in which the brutality of the
deviant sexual behavior is emphasized, and including
sexually neutral stimuli to aid in the detection of
attempts at dissimulation. Validated stimuli include
still pictures and aural stories; video materials have not
been shown to be valid in forensic assessment. Other
strategies to detect and foil faking have also been
reported. Phallometry is probably more specific than
sensitive—a deviant result is more informative than a
nondeviant profile. There have been reports of low
test-retest reliability for phallometric testing, but the
well-established discriminate and predictive validity
implies that test-retest is probably an inappropriate
index of reliability for this form of assessment.
Comprehensive discussions of the best ways to con-
duct phallometric measurement for research and clini-
cal evaluation have been provided elsewhere (see the
Further Readings and related entries).
Obviously, phallometric assessment requires spe-
cialized techniques and might not be suitable in all
forensic practice with sex offenders. In nonclinical
populations, self-reported sexual preferences can be
valid, but self-report is unlikely to be trusted in most
forensic work. There is evidence that a simple count
of relevant characteristics of past sexual victims
(a male victim, multiple child victims, a victim under
the age of 12, and an unrelated victim) is closely
related to pedophilic sexual preferences. Of course, by
definition, such a measure, though a valid index of
preferences, cannot detect changes in such interests.
Also, there is no parallel index for sexual interest in
coercive and violent sex directed toward adults.
Researchers have attempted a variety of other
cognitive-behavioral techniques to detect deviant sexual
interests. For example, a picture of a naked person in a
man’s most sexually preferred category causes maximal
interference (compared with pictures from nonpreferredcategories) in some speeded concurrent mental tasks. As
another example, when men can control how long they
look at pictures, covertly recorded viewing times have
also been found to be related to sexual preferences—for
example, heterosexual men spend the most time view-
ing pictures of adult women. Some of these latter mea-
sures are still in the development stages, while others
have been marketed to forensic clinicians. However, the
empirical basis to support their ability to detect sexual
interest in children is scant in the context of forensic
assessment, and there are no data to support their use to
detect interest in the sexual coercion of adults or in the
assessment of sex offenders’ risk of recidivism.Risk Assessment
Among Sex Offenders
Many forensic psychologists take on the task of assess-
ing the risk of recidivism represented by sex offenders.
Much of this work occurs under the aegis of statutes
mandating preventative detention for “sexually violent
persons,” “dangerous offenders,” or “dangerous people
with severe personality disorders” in various English-
speaking jurisdictions. This form of assessment is fre-
quently undertaken outside any other clinical
responsibility to provide psychological interventions or
services. In this context, the assessment of recidivism
risk among sex offenders has been controversial, with
some commentators saying that psychologists’ partici-
pation is unethical. This condemnation has been partly
based on the inaccurate assertion that sex offenders are
generally very unlikely to recidivate. In fact, the best
long-term data indicate that approximately 40% of
adult male sex offenders released from secure custody
will be apprehended for subsequent sexually violent
crime. Most forensic psychologists would probably
espouse the view that assessing the risk of sex offend-
ers can be ethically conducted as long as psychologists’
practice is in accord with the best available empirical
evidence. In that regard, and in contrast with the scien-
tifically less fruitful field of sex offender therapy, there
has been clear recent progress in empirically based risk
assessment among sex offenders.
This recent empirical progress has occurred in the
context of a much larger literature on assessment, in
general establishing (beyond any responsible debate)
the superiority of actuarial assessment over informal,
intuitive, subjective methods. The latter approach occurs
when the assessor makes the decision about what infor-
mation to select, combine, and process. In contrast, the718 ———Sex Offender AssessmentS-Cutler (Encyc)-45463.qxd 11/18/2007 12:44 PM Page 718