[pxbmjtaa] Stress or self-qi

We will consider, over many posts, a model with only a single variable which we hypothesize can explain a great deal of human behavior.

We currently lack a good name for the variable, so we borrow terms from several from other fields, knowing that it does not quite match each term's definition in other fields (so sadly likely inducing confusion at some point).

One term is stress or stress level, borrowing the idea of psychological stress.

Another term, with the scale oriented in the opposite direction, is self-qi, borrowing the term qi from Eastern medicine.  More stress is equivalent to less self-qi.