Last week’s first episode of the PBS documentary “America In Primetime,” “The Independent Woman,” focused on the evolving role of women on television – from Lucy Ricardo to Murphy Brown to  Roseanne to Nurse Jackie. Tonight’s episode, “Man of the House,” had the other side of the equation. But (and this may be a reflection of the fact that TV is still in many ways centered around men) I think it also had, more than last week’s episode, a subtext of the way in which entertainment itself has evolved, and I’m not sure I feel exactly the same way about this evolution as the producers do.

The documentary showed the grinning, supremely-wise TV dads of the 50s and early 60s – Ward Cleaver, Sheriff Andy Taylor and so on – giving way to the very flawed Archie Bunker. In the 70s, TV dads became the focus of mockery as youth culture took hold, but “The Cosby Show” marked a resurgence in the parent as hero. They played the memorable scene from the pilot episode where Theo has a little monologue about how his parents should accept him as he is, even if he doesn’t make the grades they expect him to make. The audience applauds his speech– as one of the interview subjects noted, they’d almost been conditioned to do so by similar declarations from previous TV shows. But then Cosby, just as a real parent would, shoots down Theo’s protests and insists that he will make good grades after all. The audience, not expecting this, roars with laughter and approval.

But the benign storytelling of Cosby has given way to morally-ambiguous father figures such as womanizing impostor Don Draper, conflicted mobster Tony Soprano and “Breaking Bad”’s chemistry-teacher-turned-meth-dealer Walter White.

Ron Howard told the documentarians that while TV is supposed to offer us escape from our problems, it still has to be realistic enough to give us something to relate to, or else we get something whitewashed and silly-looking, by which he seemed to mean “Father Knows Best” and the other sitcoms from the documentary’s first act.

That cuts to the very nature of entertainment – something implicit in the documentary’s very premise, and yet something the documentary danced around, except for Ron Howard’s comment and one other. I’ve never seen “Modern Family,” but someone from that show, discussing its depiction of a gay couple, remarked that he wasn’t sure if the program was leading or responding to societal changes.

I think TV has the potential to do both. TV is a business, and no TV executive is going to deliberately air something too far removed from the sensibilities or standards of that channel’s target audience. It would be financial suicide to do so. So TV reflects its audience in many ways, and in many ways we get the TV shows we deserve. If our attitudes as a society change – about sex, or gender roles, or politics – the most successful TV shows are going to be the ones that respond to or reflect those changes.

And yet, I don’t think anyone can deny that TV does have the potential, for better or worse, to nudge us in certain directions – to make things seem a little more acceptable or a little less acceptable. TV does have the power to help one demographic explain itself to another demographic – although that power is weakened as the TV audience becomes more fractured and each demographic seeks out its own programming.

So TV is both a cause and an effect of societal changes.

Of course, the actors, writers and producers who boasted of TV’s new realism, its freedom to depict meth-dealing dads and mobster dads, because, hey, that’s what society looks like, don’t seem to recognize that our taste for realism vs. idealism isn’t always a one-way street. Not every form of storytelling has to be, or benefits from being, more and more realistic. If you look at movie screens, you see that superheroes – a supremely unrealistic form which depends on you believing in outlandish premises and situations – are doing quite well.

And it’s also a fact that “realism,” as popular culture defines it, isn’t necessarily all that realistic. A truly realistic movie or TV show would be ultimately boring – because a lot of reality is pretty banal. Some of what passes for “more and more realistic” is really just “darker and darker,” which isn’t always the same thing. It may be realistic to depict a mobster using the “F” word, and it may be distracting or silly to have a mobster use some bowdlerized substitute for the F word. But it’s a fallacy to think that a TV show with 50 F-words is somehow of higher quality or greater depth or realism than a TV show with one, or none at all.

I think there’s something to be said for depicting dads, or moms, or cops, or doctors who are larger than life. I think there’s something to be said for trying to depict a world a little better than the status quo instead of a little more depressing than the status quo. That doesn’t mean that I reject anything gritty, or dark, or what have you. I certainly think there’s a place for that, and there are shows I watch and enjoy that fall in that category. (I’ve acquired a taste for “Mad Men,” a show I didn’t like at first.) I just reject the knee-jerk assumption that it’s always progress for this year’s TV show to be darker and more depressing than last year’s TV show.

“Sullivan’s Travels,” which will air later this month on TCM, was 70 years ahead of its time. It’s one of the funniest and best movies ever made, directed by the great Preston Sturges, and one of my all-time favorites. Movie director John L. Sullivan (Joel McCrea) is tired of making frothy musical comedies like “Hey, Hey in the Hayloft.” He wants to make a Serious Film about Poverty and Struggle, and has set his sights on a “Grapes of Wrath”-style novel, “O Brother, Where Art Thou?” (Yes, that title was later lifted by the Coen Brothers.) To research the film, he tries to discover first-hand what it’s like to be poor. Ultimately, however, he finds himself sitting in a room full of the imprisoned and disenfranchised watching Mickey Mouse cartoons, and he begins to recognize the value of the escapist entertainment he recently scorned.

That doesn’t mean there’s no place for “The Grapes of Wrath.” But we mislead ourselves if we think only the sad is valuable. Like Shakespeare, we need both comedies and tragedies.