With the fish still floating around the top of the RELATIONSHIP barrel after Mr. Shirky had come a-visitin’, The Sims unveils its new relationship system. I’m not a Sims player but I’m on their mailing list, which they just sent a messageboard link to explaining their system in some detail. Features stuff like this:

• Daily relationship scores and lifetime relationship scores for existing friendships are set at a high positive value. Interacting positively with your friends (hugging, dancing, etc.) from time to time will maintain your positive relationship.
• Similarly, scores for existing enemies start at a significant negative value. Interacting negatively with your enemies (slapping, pile driving, etc.) will maintain your negative relationship.

The Sims: New Relationship System