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

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

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

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%

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)

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

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

Present Study

Participants and Data Base The initial sample: 518 adult male sexual offenders who had been assessed at the MTC center (1959-1991) 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

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

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)

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

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

MAMBAC MAXEIG Results L-Mode

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

Implications

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

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

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

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

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)

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. nicklongpre@brandeis.edu