1. Jean-Pierre Guay, PhD 1,2 & Raymond A. Knight, PhD 3
The end of the dimension versus taxon debate? Evidence for a dimensional structure of sexual sadism
Nicholas Longpré, PhD 1,3
Jean-Pierre Guay, PhD 1,2 & Raymond A. Knight, PhD 3
1 University of Montreal 2 Philippe-Pinel Institute of Montreal 3 Brandeis University

2. Overview of the Talk Sexual Sadism The Present Study
Definitions
Prevalence
Dimensions
Problems
The Present Study
Analyses
Results
Convergence of results
Implication & Conclusion

3. Definitions Krafft-Ebing
The experience of pleasure caused by acts of cruelty and corporal punishment inflicted on humans or animals
Involve the desire to humiliate, hurt, hit, or destroy others to experience sexual pleasure
Diagnostic and Statistical Manual of Mental Disorders (DSM-5)
Recurrent and intense sexual arousal from the physical or psychological suffering of another person, as manifested by fantasies, urges, or behaviors
International Classification of Diseases (IDC-10)
Sadomasochism is a preference for sexual activities that involve restraints (bondage), corporal punishment or humiliation

4. Prevalence
Depending on the study, between 5% and 50% of sexual offenders are considered sadists
Sexual sadism is more common among sexual murderers than rapists
Sexual sadism is more common among rapists than child molesters
A greater prevalence of sexual sadism in psychiatric samples than in traditional prison samples
The ‘‘ true’’ prevalence is probably between 5% and 15-20%

5. Dimensions
Control & Domination (Fromm, 1977; Karpmann, 1954; Knight & Prentky, 1991)
Restraints & Bondage (Dietz et al., 1990; Nitschke et al., 2009)
Humiliation (Eulenberg, 1911; Krafft-Ebing, 1886; Marshall & Kennedy, 2003)
Violent Sexual Intercourse (Groth, 1970; O’Meara et al., 2011)
Cruelty, Torture & Mutilation (Brittain, 1970 ; Marshall et al., 2002; Schrenck-Notzing, 1895)
Ritualism & Planification (Brittain, 1970; Groth, 1970)
Sexual Arousal & Fantasy (Brittain, 1970; Kingston & Yates, 2008; Meloy, 1992)

6. Problems
No consensus on the defining features of sadism and the requisite number of diagnostic criteria
Few experts rely on all the DSM subcriteria
Poor content validity, construct validity, and discriminant validity of measures of sexual sadism
Poor interrater agreement and reliability
An absence of pathognomonic symptoms

7. Taxon vs. Dimension
Sadists have been conceptualized as fundamentally different from non-sadists (taxon)
Research is generally directed at a very specific subgroup
Ex. FBI - Sexual Murderers
An absence of pathognomonic symptoms
Behaviors supposedly discriminating sadism are found among the non-sadistic sexual offenders
And among the non-delinquent (ex. BDSM)
Several authors have argued that sadism would be better represented if it was evaluated with dimensional instrument
This dimensional conceptualization would capture the different degrees of severity in sadism

8. Present Study

9. Participants and Data Base
The initial sample: 518 adult male sexual offenders who had been assessed at the MTC center ( )
The final sample: N = 474 ; 213 rapists, 174 child molesters and 87 mixed offenders
Most participants were Caucasian (88.2%), were usually employed (67.2%) and had not completed their high school (61.4%)
MTC Data Base :
Archival records : clinical interviews, assessments, criminal and police records, parole summaries, probation and institutionalization records, and school and employment reports.
Post-commitment information : treatment and behavioral reports, work reports and summaries of program participation

10. MTCSS MTCSS - Preliminary version
Selected 25 indicators in the database
Coded as absent (0) or present (1)
Created composite indices (6 dimensions) by summing dichotomous indicators
Control and domination (3), Aggression (10), Humiliation (2), Cruelty without sexuality (4), Torture (4) and Insertion of foreign objects into orifices (2)
Analyses
Classical Testing Theory
Rasch Analysis
Two-parameter Item Response Theory Analysis
Exploratory & Confirmatory Factor Analysis

11. Taxometric Analyses
Procedures used to assess the latent structure of a construct with non-redundant evidence (Paul Meehl)
To determine whether divergent methods yield consistent results about the latent structure of a construct
Three conceptually different procedures were employed in this study: MAMBAC, MAXEIG and L-mode
Base Rate Estimate
Comparison curves were generated to compare the relative fit of the obtained data to expected curves (CCFIs/ Mean CCFI)

12. Meehl’s Taxometrics
Source : Haslam et al. (2012)

13. Results
Taxon Base Rate Estimate
MAMBAC
MAXCOV
Mean Base Rate
6 Dimensions
(0-1)
.295
.128
.212
The farther the CCFI falls below .50, the greater the support is for a dimensional structure.
The farther the CCFI is above .50, the greater the support is for a taxonic structure
Comparison Curve Fit Index (CCFI)
MAMBAC
MAXCOV L-
Mode
Mean
6 Dimensions
(0-1)
.203
.225
.448
.292

14. MAMBAC
MAXEIG
Results
L-Mode

15. Convergence of Results
Longpré et al. (2013; 2016)
Mokros et al. (2013)
MAMBAC
MAXEIG
L-Mode
CCFI
Mean CCFI
6 dimensions
(0-1)
0.20
0.23
0.44
0.29
(0-4)
0.33
0.57
0.43
MAMBAC
MAXCOV
L-Mode
CCFI
Mean CCFI
SeSaS
(0-1)
0.41
0.44
0.49
Knight et al. (2013)
MAMBAC
MAXEIG
L-Mode
CCFI
Mean CCFI
Agonistic
0.33
0.31
0.47
0.38
PCD Scale
0.41
0.27
0.39
0.35
Killing
0.11
0.37
0.03
Beating
0.21
0.02
Bondage
0.43
0.52
0.44

16. Implications

17. Summary of results
Results clearly indicate that sadism is distributed as a dimension
Unstable Base Rate
CCFI & Mean CCFI
Curve pattern (MAMBAC, MAXEIG & L-Mode)
Convergence of Results
Implications
Assessment
Cutoffs
Conceptualization of sexual sadism
Etiological Model

18. Implications 1) Assessment
Severe sadistic violence only represent a part of the large spectrum of sexual coercion – The Agonistic Continuum (Knight and colleagues)
The agonistic continuum is supported by several rigorous statistical analyses
Adequately covers the continuum - adding items that measure the lower part of the agonistic continuum
No coercive
fantasies
Coercive
Fantasies
(PCD)
Severe Sexual Sadism
Bondage,
Humiliation,
& Hurting
Scaring

19. Implications 2) Cutoff Must be determined empirically and clinically
The cutoff is influenced by the aim of the assessment (ex. Risk of recidivism vs. RNR assessment)
Confronts the idea that a specific subgroup of offenders presents a higher risk than another
Must question the use of a sexual sadism diagnoses to assist the determination of prison sentences

20. Implications 3) Conceptualization of Sexual Sadism
The language and conceptualization should be modified
More appropriate to talk about the degree of sadism rather than sadistic versus non-sadistic individuals
Reorient the way we conduct research with so-called sadistic offenders
A group of sexual offenders that adequately cover the agonistic continuum should be sufficient to study sadism
4) Etiological Model
If sadism is a matter of dose, and not of nature, it should be possible to find developmental path among sexual offenders that provide explanations of its emergence

21. Conclusion
There are two types of people ― those who divide people into types and those who don't   Anonymous Graffiti
A need to classify – Paul Meehl
This complex etiological history and individual profile are unlikely to be well described by single diagnostic categories that attempt to make distinctions at nonexistent discrete joints along continuous distributions (Widiger & Samuel, 2005)

22. Postdoctoral Associate, Department of Psychology,
Longpré, N., Guay, J.P., Knight, R.A., & Benbouriche, M. (Under Review). Sadistic Offender or Sexual Sadism? Taxometric Evidence for a Dimensional Structure of Sexual Sadism.
Nicholas Longpré, Ph.D.,
Postdoctoral Associate,
Department of Psychology,
Brandeis University,
Waltham, MA, USA.