Not sure if it's a bug or feature but I have a colonist who has "Vatgrown Soldier" backstory but is randomly (not through adulthood backstory) incapable of violence. Not a bug per se really, just IMO an immersion thing because the childhood backstory is telling how they were created to be a perfect soldier but then for no reason they can't do violence
https://www.dropbox.com/s/1iqftra6et0gtxx/Screenshot%202018-02-08%2020.11.50.png?dl=0
Your perfect soldier just didn't arrived in an army.
He got sold to some star explorer, he gave him the choise of free mind.
And then your perfect soldier decide not to be a soldier anymore.
No bug, just a bad backstory combination.
It was a bug back when the adult backstory required skills that were forbidden by the childhood backstory. It's not a bug the other way around--just a bummer for the player. (FYI, Taxonomist always forbids violence so it isn't a "random" restriction on your pawn.)
Ah got it, I guess I just didn't realize taxonomist always comes without violence and thought that the trait got assigned randomly.