Martin L. Lalumière

Assessing Treatment Efficacy in Outcome Studies of Sex Offenders

Because of the enormous human and financial costs society incurs as a result of sexual crimes, any reduction in the recidivism of sex offenders caused by treatment is very worthwhile. Although treatment can be valuable if this reduction is small, the reduction must nevertheless be real. Real effects are statistically significant differences between treated and untreated subjects in controlled studies. In general, statistical significance is a necessary criterion for clinical and economic significance. In the field of sex offender treatment, it is likely to be a sufficient condition as well. In the view of the authors, the effectiveness of treatment in reducing sex offender recidivism has not yet been scientifically demonstrated. To demonstrate the effectiveness of sex offender treatment, more well-controlled outcome research is required that can be evaluated with meta-analytic techniques.

Sex differences in intra-sex variations in human mating tactics: An evolutionary approach

Abstract We assessed sex differences in the effects of physical attractiveness and earning potential on mate selection, and sex differences in preferences and motivations with regard to short-term and long-term mating. We also investigated the effect of a variable likely to produce intra-sex variations in the selection of mating tactics, self-perceived mating success. Forty-eight university students were presented with pictures and short descriptions of persons of the opposite sex varying in physical attractiveness and earning potential. Dating interest was influenced, for both sexes, by stimulus-persons physical attractiveness and earning potential, but these two characteristics interacted only for female raters. Male and female subjects showed discrepant preferences and motivations with regard to short-term and long-term mating. In addition, self-perceived mating success was related to mating tactics in males only: Males who perceived themselves as more successful, compared to males who perceived themselves as less successful, tended to prefer and to more often select short-term mating. This effect was maximized when the stimulus person was very attractive and of high earning potential. These results confirm sex differences in mating preferences, strongly suggest a proximal factor of tactic selection, and suggest that males mating strategies may be more variable than females.

The Discriminability of Rapists from Non-Sex Offenders Using Phallometric Measures A Meta-Analysis

The authors examined how well identified rapists could be discriminated from non-sex offenders using phallometric assessments, what variables might moderate this discrimination, and whether rapists respond more to descriptions of rape than to consenting sex. Eleven primary and five secondary phallometric studies involving 415 rapists and 192 non-sex offenders were examined using meta-analytic techniques. Study effect sizes averaged 0.82 (95% confidence interval 0.16 to 1.49). Only stimulus set was a statistically significant moderator of effect size: Stimulus sets that contained more graphic rape descriptions produced better discrimination between rapists and non-sex offenders. There was a trend for stimulus sets that contained more exemplars off rape descriptions to achieve better discrimination. Also, rapists responded more to rape than to consenting sex cues in 9 of the 16 data sets and in all 8 of those using the more effective stimulus sets.

Sexual deviance, antisociality, mating effort, and the use of sexually coercive behaviors

Abstract Three high-order risk factors have been associated with a sexually coercive history in males: sexual deviance, antisociality, and mating effort. Ninety-nine young men were administered questionnaires to assess antisociality, and mating effort and 30 of them underwent a phallometric assessment of sexual deviance. Variables indexing antisociality, in particular psychopathy, were related to mating effort and self-reported sexual coercion. Variables indexing mating effort were also related to sexual coercion but those measuring sexual deviance were not. The strongest risk indicators for sexual coercion were psychopathy (as assessed by an early history of behavior problems), sensation-seeking, self-perceived mating success, and an extensive history of uncommitted sexual relationships.

Evolutionary perspectives on sexual offending

Evolutionary psychology has been successful in explaining diverse phenomena, such as the relative rarity with which people commit crimes against their biological relatives and the observed differences between males and females in romantic and sexual interest. According to an evolutionary view, the current sexual motivations of males and females were created in ancestral environments through their relationship with reproductive success. Sexual offending may arise in the context of a male sexual psychology that has been designed to maximize reproductive success by varying the proportion of mating effort and parental investment expended according to circumstances. Various kinds of sexual offending appear to be particular manifestations of this male sexual psychology either as modified by the offenders ontogenetic history or as pathology caused by some aspect of the normal sexual preference mechanism gone awry.

A test of the mate deprivation hypothesis of sexual coercion

Abstract According to the mate deprivation hypothesis of sexual coercion, males are more likely to use sexually coercive tactics if they are disadvantaged in gaining access to desirable mates. This hypothesis was tested in a sample of 156 young, heterosexual, mostly single men enrolled in a Canadian university. Differential access to mates was indexed by self-perceived mating success, self-reported sexual history, and relative earning potential. Sexual coercion was assessed using the Kosss sexual experiences survey. Results did not support the hypothesis: men who identified themselves as sexually coercive tended to have higher self-perceived mating success, had significantly more extensive sexual histories, and did not report lower relative earning potential. Coercive men reported a greater preference for partner variety and casual sex. Sexual strategy theory is used to propose two alternative models of sexual coercion.

DECEPTION AND SEXUAL STRATEGY IN PSYCHOPATHY

Abstract Clinically, psychopaths are characterized by a number of features, including the habitual use of deception in social exchanges and a history of short-term, unstable sexual relationships. These characteristics can be understood within an evolutionary framework, in terms of game theory and sexual strategies theory, respectively. However, the nature and extent of this deceptive and sexual behavior in relation to psychopathy have not been well-described. Forty-seven heterosexual men were recruited from the community and assessed for psychopathy, their use of deception in sexual and non-sexual contexts, and their sexual histories. There were significant correlations between psychopathy and the two measures of deception, and between the use of sexual deception and some indicators of sexual experience and interest. Psychopathy was not related to the relative use of sexually deceptive tactics against female vs male targets, or the relative use of tactics judged to be effective vs ineffective. This finding, along with the partial correlations involving psychopathy and the two measures of deception, suggests that psychopathy is related to a general tendency to deceive.

The sensitivity of phallometric measures with rapists

The sensitivity of phallometric measures with rapists was investigated using individual rape indices of rapists and non-sex offenders from 14 published and unpublished data sets. Sensitivity (the probability of detecting deviant sexual arousal among rapists) was determined by alternately setting the specificity (the probability of not detecting deviant sexual arousal among non-sex offenders) at 70%, 80% or 90%. Eight data sets showed sensitivity values equal to, or greater than, 60% when specificity was set at 90%. Stimulus sets that contained more brutal and graphic descriptions of rape produced higher sensitivity values. A conservative rape index cut-off score of 1.0 seems optimal in that it yields moderate sensitivity values while minimizing the number of individuals who are falsely classified as presenting deviant sexual arousal. Conditions that may increase the sensitivity of phallometric assessments are presented and discussed.

The Differentiation of Intrafamilial and Extrafamilial Heterosexual Child Molesters

It is unclear whether intrafamilial and extrafamilial child molesters differ in their sexual interest toward children and adults. Some authors have reported that both intrafamilial and extrafamilial offenders show sexual interest in children; others have found that intrafamilial offenders evidence little interest in children. The authors compared the phallometrically measured sexual interests of 19 intrafamilial heterosexual child molesters, 20 extrafamilial heterosexual child molesters, and 18 heterosexual nonoffender men recruited from the community. Stimuli consisted of 27 audiotapes describing either consensual sex with an adult partner, sexual contacts with a child using different degrees of force and violence, nonsexual aggression against a child, and neutral interactions. Nonoffenders showed a clear preference for adult stimuli; intrafamilial and extrafamilial child molesters did not discriminate between the adult and child categories and showed very similar arousal patterns.

Birth order and fluctuating asymmetry: a first look

We investigated the hypothesis that maternal immunoreactivity to male–specific features of the foetus can increase developmental instability. We predicted that the participants number of older brothers would be positively related to the fluctuating asymmetry of ten bilateral morphological traits. The participants were 40 adult male psychiatric patients and 31 adult male hospital employees. Consistent with the hypothesis, the participants number of older brothers–but not number of older sisters, younger brothers or younger sisters–was positively associated with fluctuating asymmetry. The patients had significantly larger fluctuating asymmetry scores and tended to have more older brothers than the employees, but the positive relationship between the number of older brothers and fluctuating asymmetry was observed in both groups.