Since 1964, when he began with a group of British 7-year-olds, Apted has revisited his subjects every seven years.
His latest edition is "56 Up," which examines 56-year-olds settling into middle age.
Apted said that, even if this group may be facing mortality, the film that emerged is surprisingly upbeat.
But he has learned to approach each "Up" film without preconceptions. He explained that, if he tried to predict what might happen, the film would be a self-fulfilling prophesy.
"56 Up," which was released theatrically earlier this year, airs in October on the PBS documentary series "P.O.V." Apted, 72, met Tuesday with reporters at a session of the Television Critics Association.