As part of the promotional material for 20th Century Women, director Mike Mills’ latest work, there’s a website called ‘My Mother Before Me’, where users can upload pictures of what their mother looked like before they had children. The shots, which are hazy and saturated, each come with a brief description from the child of what their mother was like; what is noticeable, however, is how superficial these descriptors are. They all seem to center around what the mothers did, or how many children they had, or how they looked – few delve into the emotional life of a mother.

It is this disconnect, between the thoughts and feelings of parents and children, that Mills explores in 20th Century Women. Like his last film, Beginners, 20th Century Women was created with material mined from Mills’ own childhood; it is no surprise, then, that he described the film as “a collective portrait of the women who raised us”. Taking on the mantle of his mother is Annette Bening, who plays Dorothea Fields, a draftsperson born into the Depression, who had one child late in life, and has since divorced her husband; rattling around in a mansion on the Californian coast, Dorothea and her son, Jamie (Lucas Jade Zumann), form the emotional core of the film. Attached to them are a variety of lodgers and friends: Abbie (Greta Gerwig), a young punk who escaped the West Coast for New York and art school, only to return following a diagnosis of cervical cancer; William (Billy Crudup), a mechanic and handyman who fixes up the house in exchange for rent; and Julie (Elle Fanning), Jamie’s best friend whose psychiatrist mother forces her to attend group therapy.

At the beginning of the film, Dorothea, fearing that Jamie is slipping away from her, enlists Abbie and Julie to help raise him into a good man. This forms the key nucleus of the drama, which could best be described as intimate, but Mills never lets us forget that a seismic cultural shift is on the horizon: Reagan, the War on Drugs, Y2K. This bigger picture spills over into the characters’ lives most obviously towards the end of the film, when a group of them sit down in Dorothea’s house to watch Jimmy Carter’s ‘Crisis of Confidence’ speech. Dorothea declares it “beautiful”, but another character says “it’s all over for him”. The other character is right: two short years after the speech Reagan will enter the White House, signalling the end of Mills’ carefree vision.

Just as with Beginners – which centred around the relationship between Oliver and his father Hal, who came out as gay in his mid-70s, following the death of Oliver’s mother – 20th Century Women examines the distance that is established between parents and children. Bening’s Dorothea is a cipher: at one point Jamie asks her “do you think you’re happy?”, to which she responds “seriously, you don’t just ask people questions like that. Especially your mom.” In another scene, after being lent feminist literature by Abbie, Jamie reads aloud a passage of Zoe Moss’ It Hurts to be Alive and Obsolete: The Ageing Woman: “I am gregarious, interested in others, and I think intelligent.” Jamie quotes, “All I ask is to get to know people and to have them interested in knowing me”. Dorothea, visibly angered by this display, cuts Jamie down: “I don’t need to read a book to know about me.” Just as Abbie and Jamie are trapped between eras – in the long stretch from the death of JFK that signalled the end of the American dream, and the rise of Reagan that signalled a new dream, for some and not all – Dorothea is caught at a turning point in the 20th century: old enough to be admitted to flight school, but too young to have been able to pilot in WWII; born late enough to trailblaze a way into being the first draftsperson in the company, but too early to break through the residual glass ceilings blocking off the top of the career. While the film might revel in its celebration of 1978 – Talking Heads had just released their first album, Times Square was still dirty, and the hardcore punk scene was emerging in Southern California – Jamie and Dorothea are both characters who are unmoored to a particular time, trapped between eras.

Mills’ directorial style is divisive, marked by his complex collaging of words and images; the use of voiceover recurs throughout the film, moving forwards and backwards through time, the epitome of an omniscience narrator. At certain points this is used for devastating effect, such as when Dorothea tells us she will die before the new millennium, from cancer caused by the cigarettes ever-present in her hands; but at other times the use of stock images and pictures can have a more distancing effect, and can easily seem twee.

Still, Mills’ greatest achievement with 20th Century Women, aside from the beautiful screenplay, is the room he gives his actors to reach inside themselves and deliver top performances. Bening is exceptional as Dorothea, alternating from motherly love to stone-cold wit, and always in complete control of her body language. Gerwig delivers possibly a career-best performance, allowing her Abbie to plumb emotional depths that usually eschew her in the kooky roles into which she is typecast; Fanning similarly is cast against type, her innocent image playing off against her secret life of smoking and sleeping around.

Last year, Mills said in an interview that “It felt like I was raised by my mom and sisters, so I was always appealing to women in the punk scene or women in my world. I always leaned to them to figure out my life as a straight white guy. So I wanted to make a movie about that.” 20th Century Women is a fitting tribute. A tribute to a particular time, and a particular place, but above all a tribute to the funny, beautiful, tender women who raised him.