Here's something for your consideration. Peter Capaldi will be the oldest Doctor Who ever. But the "trend" toward younger Doctors is actually pretty fake. The average age of an actor who takes the role of Doctor Who is about 42 years old, and the "standard deviation" for the age range is 37 to 46 years of age. Although David Tennant and Matt Smith both were on the young side of that middle-ground, having an older Doctor is long overdue. There hasn't been one since Sylvester McCoy left the show in 1989!