Scenes from the acclaimed “Up,” a documentary series that has followed a group of people every seven years since they were 7 years old. The latest installment, “63 Up,” checks in on its subjects at 63. (BritBox)

Rating: (4 stars)

To followers of the remarkable Up documentaries — nonfiction films that have revisited the same group of subjects every seven years since those subjects were introduced as 7-year-old children in a 40-minute, black-and-white program that aired in 1964 on British television — the arrival of a new installment is quite the event. As addictive as the best reality TV, but with the epic perspective of decades, not days, of observation, the films are a hybrid of the world’s second-longest running soap opera (next to “General Hospital”) and deep sociological field research.

So “63 Up,” which checks in on this motley assortment of now-63-year-old British men and women, drawn from both ends of the class system, will be greeted with bated breath by many. For those who have been dying to find out what, for example, has happened to Neil, the adorable boy who in “Seven Up!” announced that he wanted to become an astronaut, but who was seen, in subsequent episodes, struggling with homelessness and apparent mental illness, there will be no spoilers here. In the years since 2012’s “56 Up,” there has been one serious health scare and one death — and many, many grandchildren — but you’ll just have to watch the film yourself to discover what has happened to whom.

Director Michael Apted (“Coal Miner’s Daughter”), who worked as a researcher on the first film, directed all the subsequent “Up” movies, and he has become as much a friend of the people on screen as he is their biographer. As with previous episodes, Apted conducts all the intimate interviews and provides narration and clips from earlier movies to bring new viewers up to speed. Binge-watching the first eight installments before you settle into this one isn’t strictly necessary, but I wouldn’t discourage it, either. They’re that good.

Andrew is one of the subjects of the film “63 Up.” (Richard Johnson/BritBox)

Jackie is also a subject. (Richard Johnson/BritBox)

The theme of class has always been prominent in the Up series, and Apted asks several of his subjects to consider how things have changed between 1964 and now. John, a well-to-do barrister who was educated at Oxford, says he sees less rigidity and more economic mobility today — but he also speculates, somewhat clumsily, that people like him may have had it harder than members of the working class because of increased “competition” for elite jobs among the upper class.

The other grand question is whether and how the personalities of the series’ subjects were set as children. As the narrator of the first film notes, rhetorically, “Give me a child until he is 7, and I will give you the man.” Tony, a cheerful London cabdriver who grew up in the East End, and whose son has just joined the old man’s profession, agrees with that premise, saying he was a “cheeky chappie” as a boy — and he still is.

But not all the changes — or lack thereof — that the movies document are in the lives of their subjects. Apted now acknowledges, under chiding from Jackie, that his own questions in the early films were implicitly sexist. Many of his interviews with the women centered on marriage and family, while his conversations with the men focused on career and politics. (Of course, the subject of Brexit comes up repeatedly, and not one of the people asked about it supports it. Even Tony, who says he voted for leaving the European Union, has now come to regret his vote.)

For Up fans, there’s a comfortable familiarity in reconnecting with these people, whose openness with Apted, cultivated over six decades, makes them charmingly vulnerable. It’s as if we know them, too. (Not all the film’s subjects like the spotlight; one has dropped out since 2012, and another declined to participate after “21 Up.”)

But the real brilliance of “63 Up” and its predecessors isn’t the light these movies shine on Tony, Jackie, John, Neil and the rest, but the mirror they hold up in front of us. As Nick, the Yorkshire farmboy turned physics professor who relocated to America, puts it: the Up series ultimately isn’t “a portrait of Nick,” but “a picture of Everyman.”

Unrated. At Landmark’s E Street Cinema. Contains some mature thematic material. 138 minutes.