Let's talk about Stress (calmly)

I was playing my noob game starting out as Duke of Munster when I began noticing that if you give someone a lot to do (i.e. give someone land, give them a cabinet position, and give them wards) they tend to get the "Stressed" trait. In fact, I purposefully killed an annoying Steward of mine this way.

It was a 100% non-traceable murder, but how reliable is purposefully producing/relieving stress? There seems to be remarkably little discussion of the "Stressed" trait online and I would be interested in diving a little more into what causes Stress and how you can manipulate it as a game mechanic.

So, what do you guys know about "Stressed"?