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Today's underground railroad is an entirely 20th century phenomenon, tied to such modern-day sociological ills as the breakdown of the family and to increased awareness of child sexual abuse - and sometimes, hysteria about it.
Some say these underground networks that hide parents and children are a pure expression of Baby Boomer behavior, driven by self-absorbed parents who refuse to take "no" for an answer when custody disputes don't work out the way they want.
Others say the underground is a symptom of a larger malady: the courts' inability or unwillingness to properly handle cases involving allegations of sexual abuse.
Not only are women in these cases rarely believed, but judges will often punish them for making the allegations by awarding custody to the father, say representatives of children's rights, feminist and domestic violence organizations.
Fathers' rights groups counter that they are the ones who are not believed by the courts. They are deprived of their right to see their children until false accusations are resolved, they say, and their reputations are forever tarnished.
When a woman walks into a courtroom and points to her husband, is she pointing at a child molester?
The evidence is far from conclusive.
The most widely quoted study was done in 1988 by the Denver-based Center for Policy Research. In a survey of 9,000 cases, the study's authors found that 50 percent of all contested custody cases alleging child sexual abuse were substantiated. The remaining cases, the study found, either lacked sufficient evidence to back up claims of abuse, or they were false.
But judges surveyed in the Denver study said they believed even those false claims had been made in good faith; the mother had convinced herself they were true.
There are at least 140,000 substantiated cases of child sexual abuse in the United States, most of them in families, but experts believe many more are never reported. On the other hand, since the total number of child abuse fatalities has remained steady over the past decade at about 1,000 a year, some experts think that the overall number of abused children is not growing.
Still, the people who run the underground networks say too many well-documented sexual abuse cases are simply not believed by the courts.
The abusers in these cases are overwhelmingly male, although the number of women abusers is rising. And the number of reported cases is many times greater than it was three decades ago - because today, society is more than willing to talk about it.
Schools teach children the difference between "good touching" and "bad touching;" states have enacted laws to publicly identify convicted child molesters; "incest survivors" groups are all over the Internet.
With the increased awareness of child sexual abuse and incest has come the inevitable backlash: groups like VOCAL, or Victims of Child Abuse Legislation, who contend that child protection laws are overly broad, if not unconstitutional, and controversial expert witnesses like Richard Gardner, a Columbia University psychiatrist, who believe that most child abuse sexual allegations are false and are made by vindictive women.
Sexual abuse allegations occur in only a very small percentage of all contested divorces.
But these cases are the ones that tie up the courts the longest, judges say, because it is so hard to know who is telling the truth. Frequently, a child can be sexually abused and exhibit no physical symptoms. Lacking clear medical evidence, judges must then rely on expert witnesses' testimony, which often conflicts.
And some experts say there is a natural tendency by judges to disbelieve such grotesque accusations - especially in the middle of a divorce case.
"Think about it from a human perspective. Is it more believable to a judge that a woman would act in a vindictive manner during a divorce - or that a man would sexually assault a 3-year-old child?" asks Linda Girdner, author of several studies on parental abduction for the U.S. Department of Justice.
Today, Girdner says, the burden has shifted to women to prove their claims.
Twenty years ago it was very different, child abuse experts say. Issues of incest and sexual abuse within families were just beginning to claim the public's attention. And in the rare cases that a child testified in court about being molested by a parent, he or she was always considered a reliable witness.
Today, the opposite is true. The collapse of several notable day care abuse cases in the 1980s has cast widespread doubt on children's credibility, even though most child abuse experts say it is possible to obtain accurate testimony when trained interviewers talk to children.
There is one other common feature of child custody disputes involving sexual abuse charges: Rarely are they publicized.
In the few instances when they do attract newspaper or television coverage, it's usually because one of the parents has decided to go underground.
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