It has become the shorthand label for a sex abuse scandal that now haunts dioceses around the nation: the pedophile priest crisis.
But the vast majority of priests who sexually abuse minors choose adolescent boys - not young children - as their targets, according to lawyers and academics who study clergy sexual abuse.
Although public attention has focused on a handful of alleged serial pedophiles such as defrocked priest John J. Geoghan of Boston, those cases, in which priests became sexually involved with multiple boys and girls who have not yet reached puberty, are actually relatively uncommon.
"There have been very few instances where clergy got involved with prepubescent children," said Rev. James J. Gill, a Jesuit priest and physician who directs the Christian Institute for the Study of Human Sexuality in Chicago. "Most [abusers] became involved with adolescent males."
That pattern of abuse by priests has been seized on by some who would link the assaults to the high number of gay priests in the church. Scholars say that somewhere between 1 and 10 percent of the general population is gay, but that in the priesthood it may be as high as 50 percent. Yet many scholars say the link between homosexuality and the abuse of teenage boys is unclear.
Specialists also don't know what percentage of priests who molest boys are gay. And, they say, there are other equally important factors in the abuse of adolescent boys by priests, including the stunted psychosexual development of some priests, the access priests have to teenage boys, and the authority priests have over them.
The current crisis is forcing the church to take a more serious look at the issue of clergy sexual abuse; on Thursday the US Conference of Catholic Bishops promised to discuss a comprehensive national response to the issue during the bishop's next meeting in June. But the church has repeatedly declined to undertake its own study of the prevalence of homosexuality or sexual abuse among priests, and there is no indication that the church plans to examine the roots of the problem now.
Although they don't agree on the explanation, almost everyone who has examined the phenomenon of sexual abuse says the pattern of adolescent male victims is clear.
"Clearly the vast majority of victims were boys around 12 and 14 - that kind of range," said Robert A. Sherman, a local attorney who has represented 120 clergy sexual abuse victims over the past decade.
Roderick MacLeish Jr., a Boston lawyer, said 90 percent of the nearly 400 sexual abuse victims he has represented are boys, and three quarters of them are post-pubescent.
And the Rev. Donald B. Cozzens, a seminary rector in Ohio, wrote in his recent book "The Changing Face of the Priesthood" that, in discussions with other men who supervise priests, he came to the conclusion that "roughly 90 percent of priest abusers targeted teenage boys as their victims."
One of those targeted was Peter Isely, who was 13 when he said he was molested by a priest at a high school seminary in Wisconsin.
His history teacher, the Rev. Gale Leifeld, one day called him into his office to quiz him about the lessons of nationalism.
"He came up from his chair and came around and began massaging my shoulder," said Isely, now a psychotherapist, who ran a Wisconsin treatment center for victims of clergy abuse in the 1990s. "I had not a clue. What it felt like was that my head was being pumped with gas and my body was being pumped with gas. It was like anesthesia. He moved down by body, into my pants and began fondling me. Then he stopped like nothing happened."
Isely, a Harvard Divinity School graduate, said he confronted Leifeld about the abuse years later. Leifeld, now dead, never admitted abusing Isely, but in a 1994 deposition he acknowledged abusing others. He underwent extensive therapy at the Servants of the Paraclete center in New Mexico.
"I was convinced that it was my fault," said Isely, who said the assault led to a dramatic weight loss, a sleep disorder, and a sharp decline in his grades. "I thought there was something in me that was so evil and I didn't know what it was that was making him do this. ... Was Gale a homosexual? I don't know. What he was doing, in his mind I think, was some kind of initiation into a special experience of love. I was a boy who needed love and this was what love was to him. But it was really all coercion, force, and terror for me."
The church has in recent years tightened the requirements for entrance to seminaries, hoping to find only candidates who are suitable for ministry and willing to honor a commitment to celibacy.
Many of the priests who have been accused of abuse attended seminaries at a time when sex was barely discussed in class. But today, seminaries offer courses on human formation that are supposed to discuss candidly how priests are to manage sexual desire and live celibate lives. The Archdiocese of Boston has declined to make local seminarians or seminary professors available to discuss how this issue is handled locally.
The archdiocese says it puts potential seminarians through detailed psychological testing and criminal background checks. But experts say it is extremely difficult to identify a potential child abuser who has never previously molested a child.
The church also offers some treatment for priests with sexual problems at facilities such as the St. Luke Institute in Maryland. But the Archdiocese of Boston's new policy is that priests do not get a second chance - one substantiated allegation of sexual abuse of a minor ends a priest's career.
Sexual activity with a person under age 16 is illegal in Massachusetts, and immoral in the eyes of the Catholic Church and every other mainstream religious organization in America. And for a priest to get sexually involved with a boy he is supervising is not only a violation of the priest's vow of celibacy but also a clear abuse of power.
But there are distinctions between the abuse of small children and assaults on adolescents - law enforcement officials acknowledge the difference, and so do mental health professionals.
In Massachusetts, sexual acts with children are punished more severely if the children are young. The maximum prison sentence for indecent assault and battery on a child under age 14 is 10 years; it is five years for indecent assault and battery on older children. The maximum sentence for rape of a child under age 16 is life in prison; for rape of anyone older it is 20 years. And a recent study of federal sentencing found the higher the age of a victim of a sex crime, the lower the sentence.
The American Psychiatric Association defines pedophilia as sexual urges or behaviors toward a prepubescent child by someone who is over age 16 and at least five years older than the victim. The association does not have a formal diagnosis for people who are attracted to adolescent children, although some are now talking about calling the pathology ephebophila, or hebophilia.
"There is a fair amount of research that suggests that whether people abuse prepubescent or postpubescent children does make a difference," said David Finkelhor, director of the Crimes against Children Research Center at the University of New Hampshire. "People who abuse prepubescent children are more likely to be classic pedophiles who have a sexual orientation that does not include [attraction to] adults. They are more likely to be repetitive in their offending patterns, and they are harder to change and deter."
Finkelhor said that describing priests who get sexually involved with adolescents as pedophiles is not only technically inaccurate but misleading. "It suggests an inevitability of reoffending that may be exaggerated," he said.
Some go even further.
J. Philip Jenkins, a professor of religious studies and history at Pennsylvania State University and the author of "Pedophiles and Priests," said sexual conduct between priests and adolescent boys in some cases isn't even illegal.
"For a normal heterosexual man to be attracted to a 16- or 17-year-old girl might be a very stupid and dangerous thing in lots of ways, but most of us would not look at it and say, this person should be locked up for the rest of his life," Jenkins said. "For gay men, maybe there is going to be an attraction to 16- or 17-year-old boys. Is it stupid? Yes. Is it immoral? Yes. But it's in a very different category from pedophilia."
The role of homosexuality in the sexual abuse of teenage boys by priests is vigorously debated.
Sylvia M. Demarest, a Texas lawyer who won a $119 million jury award for former altar boys abused in Dallas in the mid-1990s, called a priesthood that some scholars have said is 50 percent gay "the dead elephant in the middle of the room" that few in the Catholic Church want to address.
At the same time, some observers theorize that some priests suffer from stunted sexual development - that their sexual feelings stopped changing when they entered the worlds of the seminary and the priesthood, or even before, so they act as if they were adolescents themselves.
"If you're exploring your sexuality and your sexuality is homosexual, where are you going to find a partner? You're going to find a partner with someone in your emotional age range," Demarest said. "This is where these guys are mentally and emotionally. I'm not a bang-on-the-drum antigay person, but people need to stop dancing around this issue."
But others caution that there is no evidence suggesting that gay men are more likely to abuse teenagers than straight men.
For example, Dr. Fred Berlin, founder of the National Institute for the Study, Prevention and Treatment of Sexual Trauma, said he is aware of no scientific data about how - or whether - the misconduct of gay priests with adolescent boys differs from that of the gay male population in general. Nor, he said, do gay and heterosexual adults appear to have different patterns of involvement with adolescents or younger children.
"There is no evidence that an adult gay male is any more likely to seek out a boy for sexual activities than would there be a likelihood of an adult heterosexual man seeking out a little girl for sexual activities," said Berlin, who, along with Finkelhor, was recently named to Cardinal Bernard F. Law's commission on preventing clergy sexual abuse.
In the general public, the majority of adolescent sex abuse cases involve female victims. So why do boys seem to be victimized more frequently than girls by priests?
Specialists say the answer is probably in part access: until recently, only boys were altar servers, for example.
"It has always been welcomed by parents when they see a priest taking a boy to a ballgame, or hunting or fishing or camping - the priest acts as a chaperone as well as companion - and conventionally, people have not raised an eyebrow," said Gill, the Chicago priest and doctor. "If a priest is taking a girl off for walks or swimming or any of these social or athletic events, there is some question. I think parents are a little more skeptical about turning girls unreservedly over to the priest for companionship."
And part of the answer may lie in the culture of the priesthood.
"The priesthood is a homosocial culture - all the values within the culture are male, and the reason there has been such a tolerance across the board of sexual activity by priests or bishops is because there is a boys-will-be-boys atmosphere," said A.W. Richard Sipe, a psychotherapist and former priest. "It's kind of a spiritual fraternity - like a college fraternity, but with a spiritual aura around it."
When you're young and vulnerable, being too close to that fraternity can sometimes be dangerous.
"This is an issue of power and it plays out with adolescent boys because they are particularly vulnerable in that part of their lives," said Arthur Austin, 53, who has a claim pending against the Rev. Paul R. Shanley, who allegedly molested numerous young people in his 20 years as a priest in Boston, when he often worked exclusively with adolescents. "Their hormones are just totally out of control. They are vulnerable to that kind of predation. They can be made confused very easily around issues of sexuality because they don't understand it themselves."
Austin added: "Catholicism is also, and has always been, a culture of deference. To be deferential to these guys is like second nature. It was almost like breathing. And they expected it from the laity."
Sacha Pfeiffer and Michael Rezendes of the Globe Staff contributed to this report.