Let’s say you’re a preteenager, old enough to have begun thinking that at some point Valentine’s Day isn’t going to be about getting a Starburst taped to your “Frozen” movie-themed valentines, but still not quite sure what that would look like.

And let’s say you’re among the many, many children hooked on the teenage sitcoms popularized by Nickelodeon, Disney and their ilk. (As I saw another parent tweet recently, the soundtrack to my nervous breakdown will be the theme song from “Jessie.”)

Those would be my children and their friends. And I’ve been thinking lately that as much as the societal perspective on lesbian, gay, bisexual and transgender people has evolved in popular culture, there’s a big gap just at the moment when many young people are working to figure out how they’ll fit into their adult lives.

The Disney Channel’s “Good Luck Charlie” just walked-on its first openly gay couple (calling the two lesbian parents who arrive with their 5-year-old in tow for a play date “characters” seems like a stretch), but when the teenage girl, Bree, on “Lab Rats” develops a crush on someone and it painfully pratfalls into a date, that someone is a boy. When Austin of “Austin and Ally” develops a crush on another singer and it painfully pratfalls into a date, that singer is a girl.

Whenever a teenage-crush plot line is enacted on any of the many teenage sitcom programs designed for maximum preteenage appeal, the path to true love may take many agonizing twists and turns, but the “love” will be straight every time.

Television has changed dramatically since the first gay characters appeared. In its evaluation of the quantity and quality of images of gay, lesbian, bisexual and transgender people on television, GLAAD (formerly known as the Gay and Lesbian Alliance Against Defamation), says the number of gay, lesbian, bisexual and transgender characters and stories reached an all-time high in 2013, with networks like ABC Family and Fox out front.

There are child-appropriate programs with gay, lesbian, bisexual and transgendered characters. There are programs where such characters get the “very special episode” treatment; programs where gay, lesbian, bisexual and transgender characters are just characters; and programs where some gay, lesbian, bisexual and transgender characters are just gay, lesbian, bisexual and transgender. (To its everlasting credit, Disney took the latter approach with “Good Luck Charlie.”)

There just aren’t dumb kid programs with gay, lesbian, bisexual and transgender characters.

There should be. Poorly acted, ill-conceived, tone-deaf portrayals of our most important human relationships are a tradition of American television dating back to its earliest days, and you can find no better example than today’s crop of teenage sitcoms (witness, please, the aforementioned portrayal of adoption in “Jessie,” which seems carefully calculated to produce maximum head-slapping moments among adoptive parents).

If it’s normal, we slap a theme song and a laugh track on it and start selling commercials.

Which is why, when “Austin and Ally’s” Dez gets his next crush, I’m hoping it’s on a cute boy, a waiter on roller skates, and they pratfall right into each other’s arms, just before the tray of milkshakes drenches them in more chocolate ice cream than those cups could possibly hold.

THE QUESTION of whether a father’s age at a child’s conception puts that child at an increased risk of developing various disorders has intrigued scientists for some time. In the most comprehensive study to date of paternal age and offspring mental health (published in the journal JAMA Psychiatry and reported in The New York Times by Benedict Carey), researchers found that “children born to middle-aged men are more likely than those born to younger fathers to develop any of a range of mental difficulties, including attention deficits, bipolar disorder, autism and schizophrenia.”

Compared with the children of young fathers, aged 20 to 24, those born to men older than 45 had about twice the risk of developing psychosis, the signature symptom of schizophrenia; more than three times the likelihood of receiving a diagnosis of autism; and about 13 times the chance of having a diagnosis of attention deficit disorder. Children born to older fathers also tended to struggle more with academics and substance abuse.

As with most such research, this investigation comes with many caveats for both the individual reader and broader interpretation. Those increases represent doubling, tripling or thirteen-timesing what are small numbers to begin with.

“The last thing people should do is read this and say, ‘Oh no, I had a kid at 43, the kid’s doomed,’ ” Dr. Patrick F. Sullivan, a professor of genetics at the University of North Carolina, who was not involved in the research, told The Times. “The vast majority of kids born to older dads will be just fine.”

If history is any guide, widespread panic is unlikely. In 2012, when the journal Nature reported research results suggesting that older men are more likely than young ones to father a child who develops autism or schizophrenia, because of random mutations that become more numerous with advancing paternal age (also reported by Benedict Carey in the Times), there was much commentary – largely from women delighted that the seemingly silent biological clock of men might begin ticking at last.

But in truth, that study, although more comprehensive than many that preceded it, was one in a line of continuing (and still much debated) research linking paternal age to individual mental disorders (and even lower scores on tests of intelligence) going back many years. The rate of births to fathers aged 50 and over has remained unchanged since at least 2009.

When the 2012 study was published in Nature, my editor at the time asked me if I could find older fathers now looking back with regret, or at least mixed emotions, at their decision to delay fatherhood, or take it up again at an older age.

I combed the blogs and shook the Facebook tree to no avail. Even older fathers writing blogs about their lives with children with autism took the research for exactly what they thought it was worth, as they had earlier studies. They pointed, rightly, to the limitations of the study, the wide range of other factors that go into any child’s individual development and everything that we don’t know about not just our children’s present, but their future.

Plenty of mothers, considering research about everything from Tylenol to antidepressants, do the same. One writer expressed the view of many: “I think feeling guilty is ridiculous.”

Contact KJ Dell-Antonia at:

kj.dellantonia@nytimes.com