Writing in the Times of London about the Michael Jackson trial, Oliver James, a psychologist, notes that “the thing about people with borderline personality disorder, which I believe Jackson has, is that they have a weak sense of self – as evidenced by the need to change his skin color, his erratic moods and the fact that he thinks he is Peter Pan. They are constantly acting out different personalities, which means that the boundary between fantasy and reality is blurred.”

In this as in other ways, however, Mr. Jackson stands for so much more than himself. Ours is the age of borderline personality disorder – as well as the Peter Pan culture of eternal adolescence. By coincidence, this week there are two films opening about this very subject, one very good though depressing, the other just depressing.

Pawel Pawlikowski’s “My Summer of Love” concerns two teenage girls in West Yorkshire, England, on the verge of adulthood. Tamsin (Emily Blunt) comes from a well-to-do family and has just been expelled from her boarding school for being a bad influence on others. Mona (Nathalie Press) is a working-class girl who lives above the local pub with her older brother, Phil (Paddy Considine). She never knew her father, and her mother has died of cancer.

Phil, an ex-con, has recently found Jesus and turned the pub into a prayerhall. Mona is deeply upset by this. “I miss my brother,” she tells him.

“This is the real me,” he assures her.

“I want the old Phil.”

“The old Phil didn’t make me very happy.”

“He made me happy.”

Mona, abandoned by her brother (as she sees it) and dumped by her married boyfriend, Ricky (Dean Andrews), falls back on her relationship with her new friend, Tamsin, whose own romance of suffering involves an absent mother, a philandering father, and a sister, Sadie (Kathryn Sumner), dead of anorexia. The two girls comfort each other and engage in small acts of vengeance against those whom they see as having betrayed them – Tamsin’s father and Ricky.

When their relationship becomes sexual, they seem more than ever like children trying on adult clothes to see how they fit.

In one of his most revealing scenes, the girls talk about what they want to be when they grow up. Tamsin plans to be a lawyer. Mona replies: “I want to work in an abattoir, get a boyfriend who is a real bastard, churn out all these kids, and wait for menopause – or cancer.”

Both girls, that is, realize that life has already assigned them roles that they don’t much care for, and their summer romance becomes for both – though for one much more so than the other – not so much a way of escaping as a way of imagining escape.

Mr. Pawlikowski, a Polish-born director living in England whose first feature, “Last Resort” (2000), represented a promise on which “My Summer of Love” delivers, gets tremendous performances out of both these young and hitherto barely known actresses while his director of photography, Ryszard Lenczewski, makes the Yorkshire countryside look breathtakingly beautiful. Shot on a very small budget, the film is an object lesson in how to do a lot with a little.

What I admired most of all, perhaps, was the way in which the movie uses the counterpoint between Phil’s story and that of the girls to heighten the emotional temperature. In Phil’s case, tragedy really does break through to upset the balance with comedy, as he gradually and unwillingly comes to see his new religious fervor as also just a role he is trying on – and as an alternative to one he is desperate to escape from. But at his age, and with his background, its loss is much more devastating.

The lesson is one that should have been taken to heart by “Heights,” adapted by Amy Fox from her own play and directed by Chris Terrio. A movie about role-playing and identity can be either comic or tragic. What it cannot be is stodgily moralistic, as this one is.

You wouldn’t think, in this day and age, that anyone would still bother to make a whole movie about a young man’s having to come to terms with the fact that he is gay – let alone that anyone would bother to load it up with further portentous musings about role-playing on- and off-stage, sexual fidelity, and feminist proprieties about the balance between work and relationships.

Haven’t we seen all this stuff somewhere before? That is no objection if the movie has something new or original to say, but this one does not, so far as I can see.

Even at its most basic level, as a drama, the movie has no energizing force. The story meanders on its desultory way while leaving us mystified about to why Jonathan (James Marsden) wants so badly to pass as a heterosexual and marry the beautiful Isabel (Elizabeth Banks) while obliterating all trace of his homosexual past.

This is not an implausible scenario in itself, of course, but the movie offers no hint – either in terms of social stigma or family pressures or some peculiar psychology of his own – why passing himself off as something he is not is so important to this particular young man, who hasn’t got the excuse of a teenager or a Michael Jackson that he’s just trying something on.

It’s true that passing oneself off as something one is not is the family business Jonathan is hoping to marry into, since Isabel’s mother, Diana (Glenn Close), is a world famous stage actress and director.

She, too, is acting a part – that of a sexual adventuress, though she is stung to the quick by her husband’s infidelity. And then there’s Isabel. What does she think she is playing at as Jonathan’s fiancee, busily planning her wedding, when what she really wants is to be a photojournalist?

But each of these dilemmas is more banal than the last. In “My Summer of Love” Mr. Pawlikowski has no more idea than the girls do of what are the “right” roles for them, if there are any, but he does have a deep sympathy with their desire to escape from the ones they’ve got. With “Heights,” Mr. Terrio and Ms. Fox offer only drearily predictable choices between the right way and the wrong way, self-knowledge and self-delusion.

Thus when, in the final reel, self-discovery finally comes, it does so anticlimactically. Doubtless it is a good thing if people are able finally to see the truths about themselves which have hitherto remained hidden from them, but if those truths have been obvious to us all along – or if they are such pedestrian truths as that they like boys rather than girls or that they want a career more than a relationship – we are inclined to yawn and ask; “What took you so long?”

There may be good reasons why what the authors and the audience can see about them should be so obscure and difficult to see for the characters themselves, but without some accounting for those reasons, the drama of self-discovery falls flat.