I am curious too!
I have played with townies in new savegames that already had a university diploma, adults as well as younger sims. I usually have Story Progression on (unmodded game) but have not at those moments checked for any explanation. They had 5 trait slots and the diploma seemed random: not intuitively matched to their traits/skills. Lots of townies/NPC's have diplomas when asked about 'alumnus' 'major' as social interaction. I have no idea why it happens, it would be nice to know, I mean more specifically; it does seem like one of those random features in the game. (Having UL).
Others experiencing it:
Previous active, then inactive child 'getting' diploma:
https://forums.thesims.com/en_US/discussion/815317/child-sim-gets-diploma#Comment_13306858
MTS, post 8 by Tigga07 (thread only included to show that others experience it, not to endorse anything :smiley: ):
http://modthesims.info/t/499047
Edit: I have a problem with apostrophe's.
Edit 2: wrong word..
