You've probably seen the documentary that followed a group of children into middle age, at 7 year intervals. I've only seen the first four, starting when the children were 7, back in 1964. I wondered how long he pursued the project, and it turns out, right up to when the "cohorts" were 56 in 2012. <http://www.bbc.com/news/entertainment-arts-32315451>
Answer
The series is now up to 56 Up. See http://www.imdb.com/title/tt0058578/ for additional information.
