Growing Together - Compatibility

https://simscommunity.info/2023/03/02/sims-4-growing-together-social-compatibility/

You can also set family dynamics

https://simscommunity.info/2023/03/03/sims-4-growing-together-family-dynamics/

I hope these help.

This thread might help - https://forums.thesims.com/en_US/discussion/1007423/sim-characteristics-and-social-compatibility-a-look-into-tuning-files

Compatibility can be improved by changing Sim Characteristic likes and dislikes in CAS. When you change them, take note of the traits other sims you want your sim to be compatible with have and choose accordingly. Due to CAS giving some base game examples, you may take a look into my discussion in this Forums.
If you haven't set any, the game may set one Characteristic preference for you. In addition, befriending a sim may bring up a pop-up asking if you want to add their Characteristic in your sim's likes and the other way around.

"Ray_Trace;c-18248955" wrote:
I really want to know exactly how compatibility is calculated. I have a Sim that literally hates every single Sim (dislikes all types of Sims) and he predictably has Awful Compatibility for MOST Sims...except for a small handful of people (who are just Bad Compatible).

Indeed... Though again, this thread. In short, the personality traits that the Characteristic "likes" add 3 points and traits the Characteristic "dislikes" remove 1 point. Disliking the Characteristic turns the scores around, making 3 into -3 and -1 into 1.
If your sim dislikes both Cerebral and Idealist sims for example, the Creative trait will take 3 points (Idealist), but add 1 point (Cerebral), resulting in a total score of -2 points.

If your sim dislikes every Characteristic, these traits will help to save your sim from Awful Compatibility:

• Proper (even gives 2 plus points)
  
• Unflirty (even gives 1 plus point)
  
• Good (Neutral)
  
• Self-Assured
  
• Snob
  
• Gloomy

While those are the "heavy-hitters":

• Hot-Headed
  
• Mean
  
• Bookworm
  
• Evil
  
• Goofball
  
• Jealous
  
• Geek

So theoretically, sims that dislike every Characteristic can actually have Good Compatibility with sims who have Proper, Unflirty, and Good traits. Though do remember that it also takes into account sim's likes (in activities) and lifestyles. Plus if the other sim likes the Characteristics your sim has, you can even bump it up to Amazing Compatibility.

So, in short, it could have two causes:

The other sim has "light-hitter" traits or even Proper, Unflirty, or Good trait(s).

The other sim's Characteristic likes give points toward the overall score.

I really want to know exactly how compatibility is calculated. I have a Sim that literally hates every single Sim (dislikes all types of Sims) and he predictably has Awful Compatibility for MOST Sims...except for a small handful of people (who are just Bad Compatible).