Despite a stable home life in suburban Chicago, Paul Christiano was tortured… (Alex Garcia, Chicago Tribune )
As a young boy, Paul Christiano loved the world of girls — the way they danced, how their spindly bodies tumbled in gymnastics.
In adolescence, as other boys ogled classmates, he was troubled to find himself fantasizing about 7- to 11-year-olds.
His desires remained stuck in time as he neared adulthood. Despite a stable home life in suburban Chicago, he was tortured by urges he knew could land him in prison.
"For having these feelings, I was destined to become a monster," he said. "I was terrified."
In 1999, Christiano was caught buying child pornography. Now 36, he said he has never molested a child, but after five years of state-ordered therapy, the attraction remains.
"These people felt they could snuff out the desire, or shame me into denying it existed," he said. "But it's as intrinsic as the next person's heterosexuality."
In the laboratory, researchers are coming to the same conclusion.
Like many forms of sexual deviance, pedophilia once was thought to stem from psychological influences early in life. Now, many experts view it as a sexual orientation as immutable as heterosexuality or homosexuality. It is a deep-rooted predisposition — limited almost entirely to men — that becomes clear during puberty and does not change.
The best estimates are that between 1% and 5% of men are pedophiles, meaning that they have a dominant attraction to prepubescent children.
Not all pedophiles molest children. Nor are all child molesters pedophiles. Studies show that about half of all molesters are not sexually attracted to their victims. They often have personality disorders or violent streaks, and their victims are typically family members.
By contrast, pedophiles tend to think of children as romantic partners and look beyond immediate relatives. They include chronic abusers familiar from the headlines — Catholic priests, coaches and generations of Boy Scout leaders.
Other pedophiles are "good people who are struggling," said Dr. Fred Berlin, a psychiatrist who heads the Johns Hopkins Sexual Behaviors Consultation Unit. "They're tortured souls fighting like heck not to do this. We do virtually nothing in terms of reaching out to these folks. We drive it underground."
Some of the new understanding of pedophilia comes from studies done on convicted sex criminals at the Center for Mental Health and Addiction in Toronto, where researchers use a procedure known as phallometry to identify men whose peak attraction is to children.
A man sits alone in a room viewing a series of images and listening to descriptions of various sexual acts with adults and children, male and female, while wearing a device that monitors blood flow to his penis.
Like men attracted to adults, nearly all pedophiles respond most strongly to one gender or the other — females far more often than males.
In searching for causes of pedophilia, researchers have largely dismissed the popular belief that abuse in childhood plays an important role. Studies show that few victims grow up to be abusers, and only about a third of offenders say they were molested.
Scientists at the Toronto center have uncovered a series of associations that suggest pedophilia has biological roots.
Among the most compelling findings is that 30% of pedophiles are left-handed or ambidextrous, triple the general rate. Because hand dominance is established through some combination of genetics and the environment of the womb, scientists see that association as a powerful indicator that something is different about pedophiles at birth.
"The only explanation is a physiological one," said James Cantor, a leader of the research.
Researchers have also determined that pedophiles are nearly an inch shorter on average than non-pedophiles and lag behind the average IQ by 10 points — discoveries that are consistent with developmental problems, whether before birth or in childhood.
In a 2008 study, Cantor's team conducted MRI brain scans on 65 pedophiles. Compared with men with criminal histories but no sex offenses, they had less white matter, the connective circuitry of the brain.
The evidence also points to what Cantor explained as "cross wiring": Seeing a child sets off the same neural response that men typically experience around an attractive woman.
More evidence of brain involvement comes from scattered examples of men with brain tumors or neurological diseases affecting inhibition.
In one case, a 40-year-old teacher in Virginia with no history of sexual deviance suddenly became interested in child pornography and was arrested for molesting his prepubescent stepdaughter.
The night before his sentencing, he showed up at an emergency room with a bad headache. An MRI revealed a tumor compressing his brain's right frontal lobe.
When the tumor was removed, his obsession faded, according to Dr. Russell Swerdlow, a neurologist on the case. A year later he again became sexually fixated on children. The tumor was growing back.