[jtheory]

Well. They should adjust per employee, based on their history of interaction with the employee.

In-group variation (when everyone is split up into only two groups...) is pretty enormous.

I've never liked the "Men are from Mars" approach, though it could be a stepping-stone to "many people think quite differently from me". That's a rough way to go, though (thinking a lesson learned about interacting smoothly with a "woman" or, say, a "hispanic person" will apply to everyone else in that group).