Study suggests physical deviations in the face and head of pedophiles develop during the prenatal period.

New research suggests pedophiles are more likely to have superficial facial flaws, known as Minor Physical Anomalies (MPAs). They are also more likely to be left-handed, says Fiona Dyshniku of the University of Windsor in Canada. She led an investigation into the prevalence and distribution of physical anomalies among men who are sent for sexological assessment. The study in Springer's journal Archives of Sexual Behavior adds to a growing body of evidence that suggests pedophilia develops prenatally, around the same time that such physical flaws develop.

"Evidence is steadily accumulating to support a neurodevelopmental basis of pedophilia," says Dyshniku. "If we find that pedophilia has a biological basis, with a very early, even prenatal onset, this will influence and hopefully improve methods of treatment for this group."

Facial anomalies could, among others, include having non-detached earlobes, malformed ears, or a high or steepled palate. These features develop during the sensitive first and early second trimesters while a baby is still in the womb, from the same primary embryonic tissue layer that gives rise to the central nervous system. They could develop because of prenatal exposure to viruses, alcohol or drugs, obstetric complications, or nutritional deficiencies. Such features are more prevalent among men, which might mean that the male brain is more susceptible to disruptive events during prenatal development.

"If we know more about the etiology of an injurious behavior, we can create more effective treatments and look toward prevention," says Rachel Fazio, clinical neuropsychologist and co-author of the study. "For years, it was thought that child molestation was somewhat of a learned behavior, potentially from the abusers having been sexually abused themselves as children. While this may be a factor in some cases, this is not the case in those with genuine pedophilia."

The 140 consenting participants who took part in Dyshniku's study were referred to the Kurt Freund Laboratory of the Centre for Addiction and Mental Health in Toronto to be assessed for distressing or illegal sexual behavior. The routine sexological assessment consisted of a forensic and medical file review, a semi-structured interview spanning offense and sexual history, and a phallometric test for erotic preference. The presence of specific physical anomalies and participants' right or left handedness were also assessed.

The findings suggest that the pedophiles who participated in the study were more likely to have minor facial and head anomalies than was the case for men who were not pedophiles. These deviations were more prevalent on the head than elsewhere on the body. Those with quite a few of these facial deviations also scored higher on other indicators of pedophilia.

The finding that such men are also more likely to be left-handed confirms previous research on the matter. Handedness is a result primarily of prenatal neural development and is solidified very early in life.