Report from the Committee on Sex Offenders: The Abel ...

Report from the Committee on
Sex Offenders: The Abel
Assessment for Sexual
Interest-A Brief Description

Richard B. Krueger, MD, John M. W. Bradford, MB,
and Graham D. Glancy, MB

This article briefly reviews objective methods of assessing sexual interest andlor
arousal and mentions some of the disadvantages of penile plethysmography.
Literature that supports the use of viewing time as a measurement of sexual
interest is reviewed. A detailed description of a new system of assessing sexual
interest, called the Abel Assessment, which has both subjective and objective
components, is presented. A critique of this assessment system is then offered.

Attempts have been made for years to The most widely accepted method of
obtain some objective measurement of measurement in the field is the penile
sexual interest and/or arousal patterns in plethysmograph,5 although there continue
the assessment of paraphilias. Facial elec- to be problems with its use.6 Some indi-
tromyography'; penile temperature, vol- viduals can manipulate their responses:
ume, circumference, motion, and electri- up to one-third of the individuals in a
cal bioimpedance2: pupillometry3; and laboratory will "flat-line," that is, will
abdominal temperature change4 have all show no response to stimuli. Plethysmog-
been considered in efforts to measure sex- raphy is time consuming, and it involves
ual interest and/or arousal objectively. having the patient connect his penis to a
strain gauge, something that many pa-
Thc American Academy of Psychiatry and the Law tients find repulsive.
(AAPL) Committee on Sex Offenders includes the fhl-
lowing members: Dr. Krueger is affiliated with The Into this array of assessment tech-
College of Physicians and Surgeons, Columbia Univer- niques comes the Abel Assessment for
sity, New York, NY, and is Medical Director-, Sexual Sexual Interest. It was developed by Dr.
Behavior Clinic, New York State Psychiatric Institute; Gene Abel. a prominent figure in the field
Dr. Bradford is Head of the Division of Forensic Psy- of paraphilias, formerly at the New York
chiatry, University of Ottawa, Toronto, Canada; and Dr. State Psychiatric Institute (New York.
Glancy is Assistant Clinical Professor, McMaster Uni- NY) and now at Abel Screening, Inc.. in
versity, and Assistant Professor, University of Toronto, Atlanta, GA. This instrument relies on the
Toronto, Canada. Address correspondence to: Richard
B. Krueger, MD, 315 E 68th St., Suite 6-C, New York,
NY 10021.

J Am Acad Psychiatry Law, Vol. 26, No. 2 , 1998 277

Krueger, Bradford, and Glancy

measurement of viewing time in the as- adolescent boys and girls and is also
sessment of sexual interest. available in Spanish (for men). It is self-
administered and takes about an hour to
There is support in the literature for the complete. Answers are recorded by hav-
use of this modality to assess sexual in- ing the subject "black out" items on "bub-
terest. The first mention of using viewing ble sheets" (i.e., sheets that have small
time as a measure of sexual interest is in circles to be filled in with a number 2 lead
an article by ~ o s e n z w e i ~in' which he pencil). The completed questionnaires
described the construction of an apparatus have to be mailed to Abel Screening in
he called the photoscope and its use to Atlanta for computerized scoring, and the
assess sexual interest in a group of sub- scores are then faxed back to the site.
jects. Some years later Love et al.' mea- Summaries of the answers are given for
sured the viewing time of pornography by each of 2 1 deviant sexual behaviors and
undergraduate students and correlated any admitted inappropriate sexual behav-
this with the degree of sexual guilt that ior. A cognitive distortions score, social
subjects reported. More recently, Harris desirability score, and danger registry are
et al.\resented slides of nude males and computed and presented. and a summary
females of various ages to child molesters of any accusations, arrests. and convic-
and control subjects, while recording tions that the subject endorsed is given.
their viewing times and also performing
phallometric assessments. Deviance The second part of the Abel Assess-
scores derived from the viewing time data ment consists of the presentation of 15
were able to discriminate the control sub- practice slides and two sets of 80 stimulus
jects from the child molesters, although slides depicting clothed models. includ-
not as much as scores derived from phal- ing men, women, boys, and girls, of both
lometric measures. African-American and Caucasian races.
which examine 22 categories of sexual
The Abel Assessment consists of two interest. The slides are presented on a
parts. The first part, which relies on the small projector. which is a connected to a
subject's self-report, consists of a very Macintosh computer. The subject is asked
detailed and probing questionnaire, which first to go through and view the slides and
poses questions about a patient's sexual then to go through the slides again and
history, criminal history, and any history rate them, using the computer, on a scale
of deviant interests or activity. Contained ranging from 1 to 7, which presents a
in this series of questions are a set of range of answers from highly sexually
questions that probe for deviant cogni- disgusting, to neither sexually disgusting
tions often endorsed by child molesters, nor sexually arousing. to highly sexually
as well as several questions that form a arousing. The results of this administra-
social desirability score, measuring a per- tion are e-mailed to Abel Screening in
son's unwillingness to admit to any vio- Atlanta, and in turn the computed results
lation of common social mores. The ques- of the administration are faxed back to the
tionnaire is available in separate versions site. The results are presented in the form
configured for adult men and wornen and

278 J Am Acad Psychiatry Law, Vol. 26, No. 2, 1998

The Abel Assessment for Sexual Interest

of Z scores for the objective measures. Z al; thus, the Abel Assessment may be
score transformation treats the various re- measuring something different than
sponses of each subject as a distribution plethesmography does or some of the
of scores and calculates the mean and other techniques mentioned above. Third,
standard deviation of these scores, and it is not clear whether the Abel Assess-
then each response is transformed to a ment is sensitive to treatment effects and
standard normal deviate of the distribu- able to change over time. For instance, if
tion.'' This theoretically would show the a frotteur receives masturbatory satiation
relative strength of interests that an indi- therapy, plethysmography can be used to
vidual demonstrates toward each of the demonstrate a change in sexual arousal
22 categories. pre- and posttreatment to frotteuristic
stimuli. It is not clear whether the Abel
Dr. Abel has reported, using the Cron- Assessment has this degree of sensitivity.
bach alpha coefficient test, a widely used Fourth, even the questionnaire portion
statistical test of reliability, alpha coeffi- needs to be validated, in the way. for
cients for the Abel Assessment from .84 instance, that the Clarke Sexual History
to .90, which demonstrates a high degree Questionnaire has been.13
of internal consistency for the Abel As-
Overall, the Abel Assessment has
'sessment.' promise and deserves to be tried in the
field. Technical support for the product is
While the Abel Assessment offers excellent, and all results were faxed back
promise as a method for measuring sexual promptly. The questionnaire presented in
interest in a technically simple and unob- part 1 of the assessment is superb. Training
trusive way, several problems remain. in the use of this instrument and its inter-
First, there are as yet no published results pretation are provided with the package.
describing its sensitivity and specificity.
For a new procedure, corroboration of the References
procedure and its reliability, sensitivity,
and specificity from a variety of sources Sullivan MJL, Brender W: Facial electromyo-
that can offer an independent assessment, graphy: a measure of affective processes dur-
free from any potential economic self- ing sexual arousal. Psychophysiology
interest, and communication of these re- 23: 182-8, 1986
sults through the peer-reviewed literature Bradford JMW: The use of a bioimpedance
are critical tests of a procedure's validity. analyzer in the measurement of sexual arousal
Dr. Abel has reported, however, that an in male sexual deviants. Can J Psychiatry
article including data that support his in- 31:44-7, 1986
strument has been accepted for publica- Garrett JC, Harrison DW, Kelly PL: Pupillo-
tion.* Second. the concept of sexual in- metric assessment of arousal to sexual stimuli:
terest falls more in the cognitive domain novelty effects or preference? Arch Sex Be-
and is not the same thing as sexual arous- hav 18:191-201, 1989
Beck JG, Barlow DH, Sakheim DK: Abdom-
*Note added in proof: Dr. Abel's article has now been inal temperature changes during male sexual
published (see Ref. 12). arousal. Psychophysiology 20:715-17, 1983
Barker JG, Howell RJ: The plethysmograph: a
review of recent literature. Bull Am Acad
Psychiatry Law 20: 13-25, 1992

J Am Acad Psychiatry Law, Vol. 26, No. 2, 1998

6. Simon WT, Schouten PGW: The plethysmo- Krueger, Bradford, and Glancy
graph reconsidered: comments on Barker and
Howell. Bull Am Acad Psychiatry Law 21: 10. Barbaree HE, Mewhort KJK: The effects of
505-5 12, 1993 the z-score transformation on measures of rel-
ative erectile response strength: a re-appraisal.
7. Rosenzweig S: The photoscope as an objec- Behav Res Ther 32547-58, 1994
tive device for evaluating sexual interest Psy-
chosom Med 4:150-8, 1942 11. Abel G, personal communication. January
1997
8. Love RE, Sloan LR, Schmidt MJ: Viewing
pornography and sex guilt: the priggish, the 12. Abel GG, Huffman J, Warberg BW, et a/:
prudent, and the profligate. J Consult Clin Visual reaction time and plethysmography
Psych01 44:624-9, 1976 as measures of sexual interest in child mo-
lesters. Sex Abuse: J Res Treat 10:81-95,
9. Harris, Rice ME, Quinsey VL, et al: Viewing 1998
time as a measure of sexual interest among
child molesters and normal heterosexual men. 13. Paitich D, Langevin R, Freeman R, et al: The
Behav Res Ther 34:389-94, 1996 Clarke SHQ: a clinical sex history question-
naire for males. Arch Sex Behav 6:421-36,
1977

J Am Acad Psychiatry Law, Vol. 26, No. 2, 1998