I'm not sure what you mean.
you can select the initial traits of your servant.
slaves from quests (like Cali, Emily, Maple ) has special and unique traits, ex Cali has Sturdy (takes less damage), Emily has Small Eat (eats less, like half) and maple gives you a bonus when selling slaves.
all of them will become grateful (no luxuty requeriments) after ending their quest the right way (like finding Cali parents less than 30 days after getting her, saving Emily's sister, buying maple, etc. If you fail to complete their quest right, their will not become grateful anymore.
you can get a slave to "submissive" after raping a lot of times a slave with "Likes it Rough" trait with the "entranced" spell cast on it, you can get the "like it rough" by raping a slave with "entranced"... at least this is what the code says.
as of last public version (18d), I dont think is possible to get the dominant trait to a native slave without cheating. The only way I can think of is "breeding" a slave with the dominant trait, but I do not remember if mental traits can be inherited