A bit off-topic, but... A good number of years ago, I conducted a sociology experiment, which went something like this:
1000 people were asked to participate. Each was given a folding cot, a sleeping bag, and a plastic bin as well as a brief explanation:
"There has been a disaster. You have been relocated to this facility until the situation has been remedied."
The experiment lasted 48 hours, and what we found at the end, and the hypothesis to be tested was that people will segregate themselves naturally.
It was shown to be quite true. Men (roughly 70%) tended to gather with other men. Women (nearly 98%) tended to gather with other women.
Within these groupings, we found that people of similar ethnic background also tended (roughly 70% for white people, 80% for black people, and 90% for various Asian people) to group together.
Among those who did not follow these trends, we found that nearly 90% of those who did not gather with others like themselves did so because they were acquainted with someone from another group.
We also found that 50% of the men and 80% of the women stored their plastic bins (for whatever personal items they happened to bring) under their cots.
It is, from our findings, that there is some measure of human nature that like likes like - we are drawn to and most comfortable in the company of those most like ourselves.
This isn't bigotry - that is actually a secondary reaction. It's not racist or sexist - likewise, these are secondary reactions. It's just part of how we are.
What matters most is what we do - how we act and how we treat others.
And, when the experiment was over, and no one was still told the actual nature of the experiment, we threw a very nice party and everyone had a really good time, though we did get asked a whole lot what the experiment actually was.
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As to the actual questions - we don't have these sorts of bonuses to various NPC's because it's very likely that was never considered when the system was designed, but with some urging we just might be able to get FD to look into it. It would certainly add some real flavor to our NPC's, and might just give a good reason to hire more than one at a time.