Same Face, Different Personalities: Fourteenth vs. Tenth Doctor Who
The Fourteenth is not just an aged Tenth, it is a mature Tenth, the Tenth carrying the lifetimes of his successors.
When Jodie Whittaker's Doctor regenerated last year into a Time Lord with David Tennant's face, beloved by millions of fans, the excitement of the Whoniverse fandom was palpable and contagious.
Everyone was happy to see their favorite Doctor back. But it soon turned out that Tennant would not be reprising the role of the Tenth, but would be portraying the next fourteenth incarnation of the Time Lord.
Tricky? Sure, but it actually made sense when the 60th anniversary specials finally hit our screens.
Aside from the obvious age difference (Tennant was 34 when he started playing the Tenth Doctor and is now 52), there are other differences between the two versions of Tennant's Doctor that the actor captured brilliantly in his performance.
The Fourteenth lived much longer
Three lifetimes have passed since the Tenth regenerated. That's millions of years, numerous companions, and a bunch of experience, some of which would be fatal to most species.
That's a lot of character development, and it's reflected in the portrayal of the Fourteenth. If you look closely, you can see that Tennant uses his own mannerisms from the past, but also adapts some of his predecessors.
The Fourteenth is less selfish
The Tenth was hotheaded and defensively self-centered. He used to play a blame game from time to time, driving his companions crazy. The Fourteenth is different. Even though it was Donna who spilled the coffee in Wild Blue Yonder, he stops himself from blaming her and starting a feud. Instead, he thinks of a way out of the difficult situation.
The Fourteenth is more open
The story with Rose showed how closed and emotionally unavailable the Tenth was. Even in their last moments together, he couldn't quite get up the nerve to tell the companion that he loved her. The metacrisis Doctor had to whisper it in her ear.
The Fourteenth is much more in sync and open about his feelings. He tells Donna several times how much he loves her and other companions.
The Fourteenth is more vulnerable
The emotional openness leads us to see how deeply wounded the Doctor is after losing so many loved ones and discovering the devastating truth about his origins. Where the Tenth would simply shrug off the troubling thoughts, the Fourteenth is finally willing to accept help from Donna and other friends.
The Fourteenth has a different mission
If the Tenth's goal was to have amazing adventures and make more people fall in love with the modern era of the show, which he did with flying colors, the Fourteenth's mission is very different.
He was created to allow the immortal Time Lord to grapple with the mystery of his origins and all the losses of his previous lives, to heal (even if it takes a million years), and to allow the Fifteenth a fresh start. The bi-generation twist in The Giggle made that clear.
That's why we see a mature incarnation, ready to get help and start his healing journey.
Doctor Who returns to Disney+ and BBC on Christmas Day, December 25, with the special episode The Church on Ruby Road.