NEURODEVELOPMENTAL VULNERABILITY FOR PEDOPHILIA: A TAXOMETRIC INVESTIGATION OF ITS LATENT STRUCTURE

NEURODEVELOPMENTAL VULNERABILITY FOR PEDOPHILIA:

A TAXOMETRIC INVESTIGATION OF ITS LATENT STRUCTURE

By Matthew W. King

Thesis Advisor: Dr. Jeffrey E. Hecker

A Lay Abstract of the Thesis Presented

in Partial Fulfillment of the Requirements for the

Degree of Doctor of Philosophy

(in Psychology)

May, 2010

Evidence has accumulated in support of the hypothesis that neurological disturbances during early-life development may increase an individual’s vulnerability for pedophilia – a disorder marked by persistent sexual interest in children. In individuals who have committed sex offenses, characteristics such as non-right-handedness, shorter than average height, cognitive deficits, and poor scholastic aptitude are more common in pedophiles and may be signs that there is some shared origin with the disorder, even though the majority of individuals with these characteristics do not develop it. The purpose of the current study was to ascertain whether this vulnerability likely represents a discrete precursory condition for pedophilia limited to a finite population, or a continuum of risk present to a greater or lesser degree in all individuals.

Data were obtained on 900 inmates evaluated for possible civil commitment for sexual dangerousness in Massachusetts between 1959 and 1990, through archival sources that included intelligence testing, school, legal, and clinical records, and reports of childhood history. Data were examined on characteristics of offenders that might be relevant to neurological development. Analyses centered on taxometric procedures, which can be used to distinguish whether a human characteristic should be conceptualized as a dimensional trait (e.g., height, weight) or a categorical type (e.g., gender). Results suggested that a discrete subgroup of offenders could be identified within the sample, based primarily on consistent combinations of lower intelligence, cognitive processing impairments, and symptoms of thought disturbance. Follow-up analyses involving non-neurodevelopmental characteristics revealed that offenders in the subgroup were also comparatively more likely to be interpersonally seclusive and have an early school history of discipline problems, less likely to have lived independently and been married, and, central to theory, more likely to have victimized a prepubescent child.

These results tentatively support characterizing neurodevelopmental vulnerability as a discrete condition that precedes pedophilia for some individuals. This implies that a consistent set of early-life developmental events underlies the condition. This could ultimately help discover one origin of pedophilia. Future research on the link between this condition and pedophilia should focus as much on sex offenders with the condition as on general samples of pedophiles.