@ Kuvdamos: "In 1978, he and Dr. Jean Birnbaum published a study of 175 convicted male child molesters in which they found:
"The child offender is a relatively young adult either who has been sexually attracted to underage persons almost exclusively in his life or who turns to a child as a result of stresses in his adult sexual or marital relationships. Those offenders who are sexually attracted exclusively to children show a slight preference for boys over girls, yet these same individuals are uninterested in adult homosexual relationships. In fact, they frequently express a strong sexual aversion to adult males."25
Dr. Groth identified two classic types of child molesters that he labeled fixated and regressed.26 The fixated molester is one whose development is “fixated” at childhood. In other words, he has never grown up. He typically lives a Peter-Pan existence, in a Neverland of childlike identity and behavior. He doesn’t form adult relationships easily, or if he does, the relationships tend not to be very stable. Instead, he sees children as his peers. Other adults often see him as being “very good with children”, which allows him to obtain a position of trust as a role model, leader, or caretaker.
With his primary sexual interest in children and not adults, the fixated offender fits the classic definition of a “pedophile.” And because he is fixated on children, he cannot properly be considered to be either heterosexual or homosexual he often finds adults of either sex repulsive.
On the other hand, the regressed molester is very different. His attraction to children is usually more temporary. Unlike the fixated molester, the regressed molester’s primary sexual attraction is toward other adults. But stressful conditions that go along with adult responsibly or difficulties in his adult relationships may overwhelm him, causing his sexual focus to “regress” towards children. This regression sometimes serves as a substitute for adult relationship, and his attraction to children may vary according to the varying stresses he encounters in his adult life demands.
In some cases, he may temporarily relate to the child as a peer, much as a fixated offender relates to children. But more often, he is simply lashing out against the stresses in his life, and the child becomes a convenient target. The offender may find a sense of power in his sexual relationship with a child that he doesn't get with an adult. When that happens this relationship with the child is often violent. But regardless of the nature of the relationship, the gender of the child is often irrelevant it’s the easy access and vulnerability that makes the child a target.
Regressed offenders are typically heterosexual in their adult relationships. Unlike our three percent sample, they date women and marry them. They often are parents, stepparents or extended family members of their victims. By all appearances and by their own self-identification they are straight."
"Dr. W.L. Marshall and his colleagues conducted a similar set of phallometric tests on a sample of gay and straight men, except this time they used more photos of young boys and girls covering a wider age span. They noticed that for those gay men who were attracted to males under 18, they tended to be attracted to young men who were well past the age of puberty (age 15 or older), with fully-developed adult genitalia and other features that were characteristically masculine. But when heterosexual men showed an attraction towards younger males, they tended to be attracted to pre-pubescent males (ages 9-11)"
from BoxTurtleBulletin: http://www.boxturtlebulletin.com/Articles/000,002.htm