Harvard researchers rated subjects to determine the degree of gender nonconformity in childhood. Men in the 10th percentile reported a higher incidence of sexual and physical abuse before age 11 and psychological abuse from 11 to 17, compared with those below the median percentile.
Women in the top 10th percentile reported a higher prevalence of all forms of abuse as children.
Boys, as a group, tend to be more gender-conforming in general. "There's a narrow band," Roberts said. "Girls ranged a bit more."
Dr. Madeline Deutsch, director of the transgender health program at the Los Angeles Gay and Lesbian Center, said that "recall" studies are often flawed.
"We just don't know," she said. "We don't know if it's possible that people who had not been nagged by their father for being effeminate may have forgotten, that it may not have been burned into their memory."
But Deutsch said she is "not surprised at all" by its findings based on her work with transgender youth, and said more research is critical.
"It really bothers people on a basic level when behavior is discordant with gender," Deutsch said. "When you have a child, the first thing people ask is not whether the baby has brown hair or how much the baby weighs, or whether there are birth marks. But is it a boy or is it a girl?"
She said that acceptance at home is "central" to a child's development. And those who do not conform to their gender can struggle with parental issues well into their 20s.
"I see so much substance abuse and anxiety and duress that is clearly fueled by a lifelong direct refusal by parents to validate or accept their identity or gender expression," she said. "Or there are kids who know how their parents feel and bottle it up inside. The damage is already done, there is so much internalized phobia."
The Harvard study found that 85 percent of the participants who were gender nonconforming in childhood said they were heterosexual in adulthood.
"Our findings suggest that most of the intolerance toward gender nonconformity in children is targeted toward heterosexuals," Roberts said.
"We did find a strong relationship between nonconformity and sexual orientation," she said. "They were more likely to be LGBT."
Other studies have shown that children who are perceived as gay and bullied are at greater risk for physical violence and for depression and suicide.
Biased remarks and homophobia adversely affect students' educational outcomes and personal development at every grade level, according to a study by the Gay, Lesbian and Straight Educational Network (GLSEN) in its most recent report, "Playgrounds and Prejudice."
GLSEN research reveals that gender nonconforming students are less likely than other students to feel safe at school. They also are more likely than others to be called names, made fun of or bullied.
The Harvard study also emphasizes the need for elementary schools to do more to address issues of homophobia, gender expression and family diversity.
More research is needed to understand why gender nonconforming kids experience greater risk of abuse, and to develop interventions to prevent abuse, the researchers said.
They recommend that pediatricians and school health providers consider abuse screening for this vulnerable population.
Deutsch agrees that there should be secondary protections for gender nonconforming people in the schools and in the workplace, and institutions "at the top" should set the tone for nondiscriminatory policies.
But, she said, "They have finally started looking at places outside school, in the home."