I don't know if this is related but I had two white fancy mice, think Pinky and the Brain.
They definitely had unique personalities. Minta was a risk taker, loved to explore, and always kept active, whether it was zooming through the tubes or toying w the momentum of the wheel. Crema was more of a homebody, making sure the nest was always in good shape, nibbling on what was put out for her, running on the wheel at her own pace, very timid of changes in the environment.
I think it is possible to note stress by how they react to your presence, etc, ie they may be skittish or not eating much. Sometimes Minta used to kinda bounce around like zoom in irregular patterns, but I think that was just because she was hyper from peanut butter. Hope that helps...
I may come back and edit this later to add my guessed MBTI types if it applied to rodents also.
