system
Given the following post, respond as if you're commenting on Reddit:
human
[Wall-E] After the captains die are they chosen from the passengers or is their a certain unseen human worker class that are promoted?

It would be unusual for AUTO to pick a passenger if they are a paying customer descendant.
gpt
Children receive an education and undergo aptitude testing.  Likely candidates are offered further training to become crew members.  

The best of those qualify for the position of captain when the old one retires.  Usually the captain chooses his successor based on observation over years of faithful service.

Like all things on the ship, AUTO is able to manipulate the captain and candidates.