Elevated rates of atypical handedness in paedophilia: theory and implications

Understanding Pedophilia: A Theoretical Framework on the Development of Sexual Penchants

Pedophilia is a significant public health problem. Despite its cost to society, little effort has been directed toward understanding idiographic differences in the development and maintenance of pedophilia. Extant literature emphasizes biological underpinnings and predictors of re-offense. In this article, we posit that pedophilic penchants in males originate due to language, cognition, emotions, and emotion regulation. Adverse childhood experiences, such as emotional and sexual abuse, are posited as a major contributor to the etiology of pedophilia. However, not all individuals attracted to minors present with similar childhood adversities. The development of pedophilia, in the absence of such direct training (childhood adversities), is difficult to comprehend. Relational frame theory, a comprehensive account of human language and cognition, aids in deciphering the idiographic underpinnings of pedophilia. The role of maladaptive emotion regulation in maintaining pedophilia is also described. This article presents examples of how relational frames are established and activated in distressing contexts. Finally, implications for future research are discussed.

Neurodevelopmental Differences, Pedohebephilia, and Sexual Offending: Findings from Two Online Surveys

The neurodevelopmental theory of pedohebephilia states that sexual interests in children arise from early neurodevelopmental perturbations, as, for example, evidenced by increased non-right-handedness, more childhood head injuries, and reduced intelligence and height. As corroborating evidence largely rests on samples of convicted men, we conducted online surveys among German-speaking (Study 1, N = 199) and English-speaking men (Study 2, N = 632), specifically targeting community members with pedohebephilic or teleiophilic interests. Although we detected theoretically meaningful sexual interest patterns in an embedded viewing time task, we could not detect expected neurodevelopmental differences between teleiophilic and pedohebephilic men in either of the two studies. Strikingly, pedohebephilic men who reported convictions for sexual offenses emerged as shorter and less intelligent than pedohebephilic men without convictions in Study 2. While elucidating possible third variable confounds, results have to be interpreted cautiously because of the methodological problems inherent to non-matched case control designs.

The effects of sex and handedness on masturbation laterality and other lateralized motor behaviours

Masturbation is a common human behaviour. Compared to other unimanual behaviours it has unique properties, including increased sexual and emotional arousal, and privacy. Self-reported hand preference for masturbation was examined in 104 left-handed and 103 right-handed women, and 100 left-handed and 99 right-handed men. Handedness (modified Edinburgh Handedness Inventory, EHI), footedness, eyedness, and cheek kissing preferences were also measured. Seventy nine percent used their dominant hand (always/usually) for masturbation, but left-handers (71.5%) were less consistently lateralized to use their dominant hand than right-handers (86.5%). Hand preference for masturbation correlated more strongly with handedness (EHI), than with footedness, eyedness, or cheek preference. There was no difference in masturbation frequency between left- and right-handers, but men masturbated more frequently than women, and more women (75%) than men (33%) masturbated with sex aids. For kissing the preferred cheek of an emotionally close person from the viewer's perspective, left-handers showed a left-cheek preference, and right-handers a weaker right-cheek preference. The results suggest that hemispheric asymmetries in emotion do not influence hand preference for masturbation but may promote a leftward shift in cheek kissing. In all, masturbation is lateralized in a similar way to other manual motor behaviours in left-handed and right-handed men and women.

The Handedness Index Practical Task (HI20): An economic behavioural measure for assessing manual preference

ABSTRACTBecause self-report hand preference measures are limited to investigating cognitive aspects of manual laterality, valid, easy-to-administer and economic behavioural methods are needed for capturing the motoric component of handedness. Therefore, this study introduces the Handedness Index Practical Task (HI₂₀) and tests it in a sample of 206 students (M_age = 23.79 years, SD_age = 3.01 years), half of whom were self-specified left-handers. After confirming good reliabilities at the subscale and total scale levels, k-means cluster analysis allowed an empirically based partitioning of test subjects into left- (n = 72), mixed- (n = 23) and right-handers (n = 111). To validate this categorization and the HI₂₀ index, data were compared with the Edinburgh Handedness Inventory (EHI), EHI-short, HI₂₂ and hand grip strength. The congruency between the HI₂₀ clusters and alternative categorizations ranged from 95.6% to 84.0%, while the clusters explained large portions of variance in grip strength differences. The HI₂₀ sub- and total scores showed strong correlations with other measures of lateral preference. Altogether, the freely available HI₂₀ emerges as a reliable and valid alternative for behavioural handedness assessment, whose power lies in explaining differential hand use patterns and enabling fine-grained examinations of handedness.

Widespread and interrelated gray matter reductions in child sexual offenders with and without pedophilia: Evidence from a multivariate structural MRI study

AIM

To further investigate the neuroanatomical correlates of child sexual offending and disentangle them from the neural correlates of pedophilia, using a multivariate analytical approach in order to minimize loss of statistical power.

METHODS

This study presents structural MRI data on gray matter in an incarcerated, male population of 22 pedophilic and 21 non-pedophilic child sexual offenders, and 20 violent non-sexual offender controls, based on a multivariate whole-brain approach using source-based morphometry.

RESULTS

We identify a network of several neuroanatomical regions exhibiting interrelated reduced gray matter in both child sexual offender groups relative to controls, comprising extensive clusters in the bilateral cerebellum and frontal lobe, as well as smaller clusters in the bilateral parietal, temporal, and occipital lobes, the bilateral basal ganglia, the medial cingulate and the hippocampus.

CONCLUSION

Our results speak to the interpretation that there are inter- and possibly connectivity-related brain structural abnormalities in child sexual offenders that are not (only) pertaining to pedophilia per se. Interpretations and limitations of the present data are discussed and recommendations for future works are given.

To the next decade and beyond

Sebastian Ocklenburg and colleagues have written an important and exciting summary of where laterality research might go. Perhaps reiterating some of their points, it seems important to understand the nuances of laterality. Laterality research can fall into the trap of "dichotomania" - where all laterality is seen in terms of left versus right. However, important insights can also be gained by examining the strength of laterality as well as the cooperation and competition between the hemispheres. Care also needs to be taken when examining individual differences between left- and right-handers. Studies, which may suffer from type 1 errors, often stigmatise left-handers with a host of negative traits. Pre-registration and the reporting of effect size may eliminate this bias.

Psychometric properties of the Spanish version of the Edinburgh Handedness Inventory in a sample of Chilean undergraduates

An individual's nervous and cognitive systems are lateralized, and handedness represents a behavioral manifestation of such organization. Therefore, accurately and reliably measuring handedness has repercussion on our understanding of both the human brain and cognition. The Edinburgh Handedness Inventory (EHI) is the most frequently used instrument to measure handedness both in clinical practice and research. We assessed the psychometric properties of the Spanish version of the EHI in a sample of 348 Chilean university students by confirmatory factor analysis. Cronbach's alpha and composite reliability were calculated to evaluate the internal consistency and reliability of the EHI, while the average variance extracted was estimated to evaluate its convergent validity. A 10-item unifactorial structure was confirmed, with factor loadings ≥0.50, showing excellent goodness-of-fit indicators, very high internal consistency and adequate composite reliability and convergent validity. Socio-demographic variables (sex, area of residence and belonging to an indigenous people or community) did not significantly modulate the EHI scores. Overall, by using this validated version of the EHI to accurately and reliably measure handedness in the greater Spanish population, researchers will be able to produce robust data to tackle the still open questions of lateralization in human cognitive and neural architecture.

Are There Any Biomarkers for Pedophilia and Sexual Child Abuse? A Review

The use of biomarkers in medicine is a common and valuable approach in several clinical fields. Understanding the relationship between measurable biological processes and clinical outcomes not only is indispensable in the face of understanding physiological processes in healthy as well as in diseased organisms but also for understanding and evaluating treatment effects. Therefore, also in the context of forensic psychiatry, biomarkers and their potentially beneficial effects are of growing interest. The objective of this review is to examine if there are biomarkers that may serve as a tool to support diagnostic process, treatment evaluation, and risk assessment of pedophilic individuals and child sexual offenders. In the first part, we present an overview of the current neurobiological, as well as physiological and psychophysiological approaches to characterize pedophilia and child sexual offending. Secondly, we discuss and evaluate the impact of these approaches on the development of biomarkers for diagnosis, therapy, and risk assessment in pedophilic subjects and child sexual offenders. We conclude that a lot of research has already enhanced our neurobiological knowledge about pedophilia and child sexual offending. Although there surely exist promising parameters and approaches, in our view currently none of these is ready yet to serve as a clinically applicable diagnostic, response, or predictive biomarker for pedophilia and child sexual offending. Therefore, further work remains to be done. The development of a composite diagnostic biomarker to assess deviant sexual interest, combining several measures like functional magnetic resonance imaging, electroencephalogram, eye tracking, and behavioral approaches seems to be most promising. A valid and reliable measurement of deviant sexual interest, insensitive to manipulations could significantly support clinical diagnostic process. Similarly, regarding therapy evaluation and risk assessment, a composite biomarker to assess inhibitory control functions seems to be promising. Furthermore, the application of the Research Domain Criteria-approach, a new approach for investigating and classifying mental disorders, offers the possibility to take research to a new level.

Inhibition and attentional control in pedophilic child sexual offenders - An event-related potential study

OBJECTIVE

Impaired response inhibition might play a role in child sexual offences. Recording of event-related potentials (ERPs) can help to clarify whether child sexual offenders (CSOs) show an altered processing of stop signals and commission errors.

METHODS

In the current ERP study, we investigated these processes in a Go/Nogo task on two groups of CSOs, pedophilic contact CSOs and non-contact CSOs (child pornography offenders), as well as on non-offenders as controls.

RESULTS

Behaviorally, CSOs showed a slight, but non-significant increase of the false alarm rate to Nogo cues, as compared to controls. The amplitudes of the ERP components N2 and P3 to Nogo cues followed by correctly withhold responses did not vary between CSOs and controls. The analysis of the ERPs to committed errors showed that the Ne amplitudes (reflecting error detection) did not differ between the groups either, whereas the Pe amplitudes (reflecting error evaluation and error awareness) were strongly diminished in CSOs. This diminishment was primarily found in contact CSOs.

CONCLUSIONS

The findings suggest that response inhibition, processing of stop signals, and error detection are not necessarily impaired in CSOs. However, CSOs appear to dedicate less cognitive resources to the evaluation of committed errors.

SIGNIFICANCE

This selective alteration could reflect a reduced sense of responsibility for misconduct in this offender group, which might contribute to their delinquent behavior.

Clinical characteristics associated with paedophilia and child sex offending - Differentiating sexual preference from offence status

Contrary to public perception, child sex offending (CSO) and paedophilia are not the same. Only half of all cases of CSO are motivated by paedophilic preference, and a paedophilic preference does not necessarily lead to CSO. However, studies that investigated clinical factors accompanying and contributing to paedophilia so far mainly relied on paedophiles with a history of CSO. The aim of this study was to distinguish between factors associated with sexual preference (paedophile versus non-paedophile) and offender status (with versus without CSO). Accordingly, a 2 (sexual preference) × 2 (offender status) factorial design was used for a comprehensive clinical assessment of paedophiles with and without a history of CSO (n = 83, n = 79 respectively), child sex offenders without paedophilia (n = 32) and healthy controls (n = 148). Results indicated that psychiatric comorbidities, sexual dysfunctions and adverse childhood experiences were more common among paedophiles and child sex offenders than controls. Offenders and non-offenders differed in age, intelligence, educational level and experience of childhood sexual abuse, whereas paedophiles and non-paedophiles mainly differed in sexual characteristics (e.g., additional paraphilias, onset and current level of sexual activity). Regression analyses were more powerful in segregating offender status than sexual preference (mean classification accuracy: 76% versus 68%). In differentiating between offence- and preference-related factors this study improves clinical understanding of both phenomena and may be used to develop scientifically grounded CSO prevention and treatment programmes. It also highlights that some deviations are not traceable to just one of these two factors, thus raising the issue of the mechanism underlying both phenomena.

Preliminary validation of the Portuguese Edinburgh Handedness Inventory in an adult sample

The Edinburgh Handedness Inventory (EHI) is persistently the most used inventory to evaluate handedness, being neuropsychological investigation and clinical practice. Despite this, there is no information on how this instrument functions in a Portuguese population. The objective of this study was therefore to examine the sociodemographic influences on handedness and establish psychometric properties of the EHI in a Portuguese sample. The sample consisted of 342 adults (157 men and 185 women), assessed with a battery of neuropsychological tests. The mean EHI Laterality Quotient was 63.52 (SD = 38.00). A much high percentage of ambiguous-handedness compared to left-handedness was detected. An inconsistency was found between the preference for formal education activities (writing-drawing-using scissors) and the remaining EHI activities. From sociodemographic variables, only age, area, and regions of residence showed significant influence on EHI scores. The reliability and temporal reliability of EHI were adequate. Confirmatory factor analysis indicated a one-factor model (χ²/df = 2.141; TLI = 0.972; CFI = 0.979; RMSEA = 0.058). The inconsistency between formal education and nonformal activities could be an indicator of social pressure. The present data give support for the notion that handedness measured by EHI is potentially sensitive to sociodemographic and cultural influences.

The Puzzle of Male Chronophilias

In this article, I return to the idea that pedophilia, a sexual interest in prepubescent children, can be considered a sexual orientation for age, in conjunction with the much more widely acknowledged and discussed sexual orientation for gender. Here, I broaden the scope to consider other chronophilias, referring to paraphilias for age/maturity categories other than young sexually mature adults. The puzzle of chronophilias includes questions about etiology and course, how chronophilias are related to each other, and what they can tell us about how human (male) sexuality is organized. In this article, I briefly review research on nepiophilia (infant/toddlers), pedophilia (prepubescent children), hebephilia (pubescent children), ephebophilia (postpubescent, sexually maturing adolescents), teleiophilia (young sexually mature adults, typically 20s and 30s), mesophilia (middle-aged adults, typically 40s and 50s), and gerontophilia (elderly adults, typically 60s and older) in the context of a multidimensional sexual orientations framework. Relevant research, limitations, and testable hypotheses for future work are identified.

Diffusion Tensor Imaging of Pedophilia

Pedophilia is a principal motivator of child molestation, incurring great emotional and financial burdens on victims and society. Even among pedophiles who never commit any offense,the condition requires lifelong suppression and control. Previous comparison using voxel-based morphometry (VBM)of MR images from a large sample of pedophiles and controls revealed group differences in white matter. The present study therefore sought to verify and characterize white matter involvement using diffusion tensor imaging (DTI), which better captures the microstructure of white matter than does VBM. Pedophilics ex offenders (n=24) were compared with healthy, age-matched controls with no criminal record and no indication of pedophilia (n=32). White matter microstructure was analyzed with Tract-Based Spatial Statistics, and the trajectories of implicated fiber bundles were identified by probabilistic tractography. Groups showed significant, highly focused differences in DTI parameters which related to participants’ genital responses to sexual depictions of children, but not to measures of psychopathy or to childhood histories of physical abuse, sexual abuse, or neglect. Some previously reported gray matter differences were suggested under highly liberal statistical conditions (p(uncorrected)<.005), but did not survive ordinary statistical correction (whole brain per voxel false discovery rate of 5%). These results confirm that pedophilia is characterized by neuroanatomical differences in white matter microstructure, over and above any neural characteristics attributable to psychopathy and childhood adversity, which show neuroanatomic footprints of their own. Although some gray matter structures were implicated previously, only few have emerged reliably.

Minor Physical Anomalies as a Window into the Prenatal Origins of Pedophilia

Evidence is steadily accumulating to support a neurodevelopmental basis for pedophilia. This includes increased incidence of non-right-handedness, which is a result primarily of prenatal neural development and solidified very early in life. Minor physical anomalies (MPAs; superficial deviations from typical morphological development, such as un-detached earlobes) also develop only prenatally, suggesting them as another potential marker of atypical physiological development during the prenatal period among pedophiles. This study administered the Waldrop Physical Anomaly Scale to assess the prevalence of MPAs in a clinical sample of men referred for assessment following a sexual assault, or another illegal or clinically significant sexual behavior. Significant associations emerged between MPA indices and indicators of pedophilia, including penile responses to depictions of children, number of child victims, and possession of child pornography. Moreover, greater sexual attraction to children was associated with an elevated craniofacial-to-peripheral anomalies ratio. The overall sample demonstrated a greater number of MPAs relative to prior samples of individuals with schizophrenia as well as to healthy controls.

The Neurobiology and Psychology of Pedophilia: Recent Advances and Challenges

A pedophilic disorder is recognized for its impairment to the individual and for the harm it may cause to others. Pedophilia is often considered a side issue and research into the nature of pedophilia is delayed in comparison to research into other psychiatric disorders. However, with the increasing use of neuroimaging techniques, such as functional and structural magnetic resonance imaging (sMRI, fMRI), together with neuropsychological studies, we are increasing our knowledge of predisposing and accompanying factors contributing to pedophilia development. At the same time, we are faced with methodological challenges, such as group differences between studies, including age, intelligence, and comorbidities, together with a lack of careful assessment and control of child sexual abuse. Having this in mind, this review highlights the most important studies investigating pedophilia, with a strong emphasis on (neuro-) biological studies, combined with a brief explanation of research into normal human sexuality. We focus on some of the recent theories on the etiology of pedophilia such as the concept of a general neurodevelopmental disorder and/or alterations of structure and function in frontal, temporal, and limbic brain areas. With this approach, we aim to not only provide an update and overview but also a framework for future research and to address one of the most significant questions of how pedophilia may be explained by neurobiological and developmental alterations.

Factor structure of the Edinburgh Handedness Inventory versus the Fazio Laterality Inventory in a population with established atypical handedness

The Edinburgh Handedness Inventory (EHI) has consistently remained the most used handedness inventory despite its limitations. The psychometric properties of handedness inventories, however, are increasingly important due to their use in matching groups for neuroimaging research. This study compared the performance of the EHI and the Fazio Laterality Inventory (FLI) in a population with atypical handedness. Whereas the EHI demonstrated a single-factor loading in this population, the FLI's previously demonstrated single factor dissociated into two factors: fine motor/ballistic movements and expressive/instrumental movements. This dissociation is similar to that seen when tests of cognitive constructs--which tend to load on a single factor in intact populations--dissociate when administered to populations with difficulties in the assessed domain. This pattern of performance lends further support for the use of the FLI to more accurately assess handedness. Future research in other populations with atypical laterality may illuminate additional factors of the FLI.