Of course that all matters, you dont want to have an idiot or sissy for a leader, you actually can take part in developing your family members thrugh there lives, there are several ways to do so,
Traits and personalyties are obtained during there life time by:
*learning (developing academys for a lerning basis)
*gaining experiance in wars
*and suceeding nowlegde and traits
from other family mambers such as fathers,
brothers or beatificators
I personly like best when I suceed my knowledge which I got throug the campaing to my favorite son, or my brother, it depends how I like the Title of Empire to be passed on, or simply by the right of harritage as the oldest son, or by their achivements in thier lives, but then someone get the eternal shame upon their name, his right as the secesor, he was disherited in public, and I sent him far away to an island, Palma for instance he,he..
I just can not be sure in there loyalty any more