(CNN) -- Tuesday's CNN.com story about transgender children and their families shed light on an emotional topic and provoked strong response.
"Transgender kids: Painful quest to be who they are" centered on identity, gender, health, parenting and child development. It's not unusual for a popular story on CNN.com to have hundreds or thousands of responses, but the overwhelmingly negative tone of Tuesday's comments raised the question about the root of the hostility. What exactly provoked such harsh opinions?
The discomfort toward transgender people comes from challenging conventions, said one academic who focuses on social attitudes and behavior.
In American culture, sex and gender belong in one of two categories, said Diane Everett, professor of sociology at Stetson University in DeLand, Florida. As soon as humans are born, the first thing people ask is whether the baby is a boy or girl.
"We tend as a society to put people into boxes," she said. "Someone who is transgender is not only crossing gender boundaries, but also defying them. If people can't relate to you as an either-or, they have a hard time relating to you in their general comfort level."
Then there are people who for religious reasons believe transgender is fundamentally wrong, that "God created man and woman. Automatically, man is male, woman is female, and they shouldn't cross these lines."
The issues usually end up in a debate about which bathroom transgender people use, Everett said. It's a symbol of the entire controversy because it has to do with gender, sexuality and comfort level.
The discomfort stems from the view that a person is either female or male -- and in rare cases, intersex. Changing what you're born with is "basically self-mutilation," said Regina Griggs, executive director of Parents and Friends of Ex-Gays & Gays, a group that works with people who no longer practice gay, lesbian or transgender lifestyles. "You're talking about surgery to alter who you really are from a biological standpoint."
People with gender identity disorder deserve proper medical and psychiatric help, she said.
Griggs said she has heard from parents who have transgender staff in their children's schools and that "they're being told that it's normal, natural and healthy, (that they) have to respect them and approve."
"Why are we hiring people who are cross dressing? Why should children be told that's acceptable behavior? That's where the line is being drawn. We're telling people it's natural, healthy, normal behavior and it's still classified as a mental illness."
Gender identity disorder is listed in the Diagnostic and Statistical Manual of Mental Disorders, the "bible" of psychiatry.
Transgender people challenge the ideas ingrained in society about gender and sex, said Mara Kiesling, founding executive director of the National Center for Transgender Equality. People are taught that boys stay as boys, girls as girls, and that boys will marry girls.
"All of those things are true for most people," she said. "It's true that most people are either male or female and it is immutable for most people. Most boys act like stereotypical boys, most girls act like girls. What we're learning now is none of those things are immutable as we were taught. It's striking at some naïve orthodoxy that people have been taught by society since our childhood."
Transgender people face minority stress, meaning that they're made to feel unwelcome or an odd minority, Kiesling said. They also face stigma, sometimes from their own family, job discrimination and bullying.
"Why in the world would anybody be so hostile about parents really trying to understand something about their children that wasn't in the original playbook as parents?" she said. "They're doing the best they can trying to do right by their kids."
The hostility can come at surprising times.
A transgender woman, Amber Yust, who changed her name from David, went to her local Department of Motor Vehicles in San Francisco to update her license last year. She received a letter from one of their employees accusing Yust of acting in a way that is "an abomination that leads to hell." That employee was identified and subsequently resigned.
Chaz Bono, born a girl to entertainers Sonny and Cher and now publicly transitioning to life as a man, has been the most recent transgender person to be the focus of news reports. When it was announced that Bono would compete on "Dancing with the Stars," conservative family groups protested and started an online campaign against the popular reality show.
A Foxnews.com contributor chimed in suggesting that parents not allow their children to watch Bono on TV, because it could inappropriately influence children.
"The last thing vulnerable children and adolescents need, as they wrestle with the normal process of establishing their identities, is to watch a captive crowd in a studio audience applaud on cue for someone whose search for an identity culminated with the removal of her breasts, the injection of steroids. ..." wrote Dr. Keith Ablow, psychiatrist and member of the Fox News Medical A-Team.
His post got 33,000 Facebook recommends and more than 2,000 Tweets.
But not everyone on the network agreed. His views were challenged by Fox anchor Megyn Kelly, who questioned his evidence.