Howz about this one:
The ammount of time that a child spends with his father will effect how many of his fathers traits rub off on him. This will not be limited to childhood. After the character comes of age, time with the father (or faction leader) will effect their traits and skills. If a son stays with his father in a city, he will learn more management related skills from his father. On the other hand, if the son spends more time with his father campaigning, he'll learn more about strategy and warfare from his father.