Despite evidence of their protective value, the words cause trouble sometimes. Two weeks after Rohdenburg gave her lesson in March, as required by a new state law, a biology teacher at a public high school in Idaho said "vagina" in one of his classes. Several parents filed complaints against the teacher, Tim McDaniel, and now he is under investigation. Last June, Michigan State Representative Lisa Brown was banned from Lansing's state house floor after she said "vagina." One sexual-abuse prevention trainer in New England tells the story of a mother who discovered her first-grader had learned the word "penis" in school. The mother pulled her daughter from class. "You've destroyed her innocence!" she shouted at the school's counselor.

Yet while cases like these make headlines, educators increasingly believe—and parents seem increasingly to accept—that teaching and using plain and accurate language to describe the human body can help children live healthier lives. "We need all adults to be partners in teaching healthy childhood sexual development," says NSVRC's Palumbo, and "square one is body parts." Educators and parents should communicate accurately, without stigma or shame, she says. This helps children who "have important health questions or an experience they're concerned about talk with adults about their concerns," whether the child is seven or seventeen. Parents are children's most important teachers, it's true, but, as educators like Palumbo notes, not every one of the 55 million children who goes to school in America each day comes home to a CDC-ideal "safe, stable, and nurturing environment." One study indicates 34 percent of child sexual abuse offenders are family members. Meanwhile, one in ten students reports being sexually victimized by school employees, predominantly teachers and coaches.

Anthony Rizzuto, Ph.D., is the child psychologist who oversaw implementation of prevention education in Catholic schools and churches in more than 360 Boston parishes, more than 210,000 children in all, in the wake of revelations of widespread abuse there. It was a time of very high emotion, Rizzuto says, with "a lot of anger, a lot of distrust." The issue of language came up at just about every informational meeting held, Rizzuto says. "In response, we described the relevant research and the reasons for using anatomically correct terms—to give children the language they need should they need to report, especially should they need to report to law enforcement or the department of social services." While it's hard to measure the impact of teaching anatomically accurate terms within the context of the comprehensive programs put in place, Rizzuto says, "the children came to learn that school and church was a safe environment to disclose and that if they chose to do that, people around them would know what to do to make it stop." Reports were tracked, he says, and indicated "an increase in children who were self-disclosing ... Children got comfortable, and started coming to teachers and parents."