Five years since his semi-autobiographical Beginners and writer-director Mike Mills mines his life once more for this engaging drama. Set in Santa Barbara in 1979, fifteen-year-old Jamie (Lucas Jade Zumann) lives in a dilapidated house in the process of remodelling with mum Dorothea (Bening), Bowie-obsessed lodger Abbie (Gerwig) and mechanic/handyman William (Crudup). Mum fears she's out of touch with this new Punk generation and so calls on Abbie and Jamie's clued-in friend Julie (Fanning) to help school her son in the ways of righteousness…

20th Century Women is as fun as it is frustrating. The story is, like Beginners and Mills' 2005 teen drama Thumbsucker before it, a bit wishy-washy but its characters and the performances keep one entertained through its unsure moments. A wonderful Bening should be awarded for an Oscar nomination not just for her strong turn but in dragging her character through the inconsistencies: the script is at pains to stress that she's from a different generation and she struggles to understand Punk and New Wave ("They know they’re not good, right?") but she seems a cool and hip mum. When the family car catches fire she shrugs it off and invites the fireman to dinner but once Jamie starts talking to her like an adult she shuts him down. It's sometimes difficult to get a grasp on what she's about.

Mills, forgoing narrative drive to get under the fingernails of his characters, has no qualms about stopping everything in its tracks to toss in pop culture montage recaps or Abbie and Julie's backstory (the former a photographer who may have cervical cancer, the latter is forced to attend group therapy sessions by her analyst mother). Abbie, Julie and Dorothea are colourful, rounded characters and hanging out with them is fun. And then there's Jamie.

It’s not clear just what the problem is here. Dorothea wants him to "be a better man" but he's only fifteen, and the moment that sparks mum's intervention isn't alcohol or drugs or a snarly attitude or poor grades: he's accidentally rendered unconscious when a fainting game goes awry. Is that strong enough to make someone panic like she does? Moreover, Jamie isn't afforded the same depth as those in his orbit: bar his unrequited love for Julie he's a blank canvas, there merely to be moulded by the women around him.

And this moulding suffers from shoehorning, like the clunky house remodelling metaphor. Jamie is given a plethora of feminist literature to digest in a 'Read this, silly boy' fashion, while Abbie demands that everyone around the dinner table say 'menstruation.' While they are correct to attempt to raise his consciousness these moments never feel part of this carefully constructed world the way everything else does. This, and the time wasted with Crudup's sensitive bohemian who has little impact on those around him, distract from what's at the centre of this drama: the inability for a mother and son to communicate.