Hi,
The sims could grow up in different cultural/social environments and obtain habits/point of view influencing their personality.
For example the lifepath could be inspired by the social classes in The Sims 2 :
- Gearheads
- Jocks
- Techs
- Socialites
Or the lifepaths could be Urbz and country sims.
An urban sim would be clumsy with farm activities and less efficient, a country sim would feel uncomfortable in big cities like San Myshuno and Del Sol Valley.
Or it could be something else, I think if twins grew up in different cities (one in San Myshuno and the other in Sulani), they would get different habits and point of view due to the influence of the environment.
Likes and Dislikes could add Home World preferences (City, suburb, beach, mountain, ...)