Robert Redford in The Company You Keep plays a somewhat older character than we are used to seeing him play. But he still has a somewhat middle-aged demeanor.
What is less well known is that Redford [who doesn't look or show his age] is the same age that Henry Fonda was when he starred in On Golden Pond; 76.
This seems remarkable. The perception and definition of what it means to be old [or even elderly] has changed in the last 30 years. Granted Fonda was suffering from heart disease late in life, which compounded how old he looked.
Redford plays the father of a 12 year old girl in the movie. It would be tough to imagine him playing an elderly patriarch in a movie like On Golden Pond just as surely as it would be hard to imagine Fonda playing the role that Redford plays in The Company You Keep.