Good Boys’ trailer begins with producer Seth Rogen explaining to its trio of 12-year-old heroes that they are actually too young to watch their own movie. “That’s fucked up,” says one of the kids (which kind of sets the tone for the whole movie). Rogen replies: “You can say that, but you can’t watch yourself say that: that’s fucked up. Welcome to Hollywood.”

Children acting in movies they’re too young to watch is not exactly new. You think back to Jodie Foster playing a child prostitute in Taxi Driver, aged 14, or Linda Blair in The Exorcist and you wonder whether their portrayal of lost innocence was down to real lives lived too fast or just good acting. But it feels more commonplace these days, in a landscape filled with child-centred horrors (It, Stranger Things), violent action movies (remember Kick-Ass?), serious trauma dramas (such as Room, whose star Jacob Tremblay is one of the trio in Good Boys), and now, junior raunch comedies. In Good Boys, our potty-mouthed sixth-graders naively encounter grownup stuff such as drugs, violence, online porn and sex toys. Are they swearing like troopers for comic effect, or is this just what it is like to be a 12-year-old now?

By coincidence, we have another movie out this week with the opposite predicament. Dora and the Lost City of Gold updates the kids’ TV cartoon into a live-action Tomb Raider/Spy Kids-style adventure, with its sunny, curious heroine now high-school age (played by 18-year-old Isabela Moner). Despite being a good five years older than the boys of Good Boys, and therefore old enough to go to see it in a cinema, Dora is unwaveringly wholesome and squeaky clean – incongruously so, for some critics. Variety noted the movie’s “virtually asexual chemistry”. The Hollywood Reporter’s Todd McCarthy went one further and complained the movie was “committed to projecting a pre-sexualized version of youth, while throbbing unacknowledged beneath the surface is something a bit more real”. Some were quick to point out that “pre-sexualized” youth might be a good thing in a PG-rated family movie, and by the way, eeeeeuw! “Would he prefer a younger pre-adolescent cast or a hornier version of this movie?” asked geek culture site The Mary Sue.

Good Boys and Dora are two facets of the same 21st-century anxiety. We don’t want children to grow up too fast or too slow. We don’t want them to turn out like the Good Boys but suspect they might. We do want them to turn out like Dora but suspect they won’t. We make kids’ movies for kids and we make kids’ movies for adults. Strike the right balance, and you can play to both (I’d hold up Stand By Me, Night of the Hunter, Moonrise Kingdom, even ET). Either way, it is easier to blame the movies than ourselves.