If a sim has more MC assigned traits than there are defined slots, they stand to lose the 'extra' ones upon traveling to other worlds and there may be issues when they age up.
The same applies to younger sims, was just using adults as an example.
The MC Cheats module is required, the commands are on NRaas > MC > (Sim) > Advanced > Traits. If you wish certain particular adult sims to have more than 5 traits, you can assign the two special Uni slots with MC even if the sims do not qualify, and assuming you have the Uni EP in play, or you can assign them as many traits as you want in the regular slots. What that means is that if you allow let's say adults to have 8 trait slots (plus the two for Uni graduates and the high level social group accomplishment), then all adult sims in town will stand to automatically pick up 8-10 traits. If you wish to increase the number of defined trait slots, the NRaas mod to use would be Retuner. It depends on how you want to arrange this.
