In my view, positive accepting elements see information that is at a sort of balanced point. ("set point") The element desires elevation beyond the median, and it is the role of the negative producer to produce the means by which this elevation may occur. The negative producer, which is below its set point, will raise its content level to its median by performing the functions necessary to elevate the acceptor.

Vice versa for negative acceptors and positive producers: the problem at hand is that the acceptor is below an acceptable level, and the means for raising its level is the elevation of the positive producer. For example, take INTj: -Ti says there is not enough structure to meet the abundance of +Te facts on hand. To create enough structure, it is necessary to offer new possibilities of structure within existing structure: this is +Ne.

Observe thus, that the set point of a negative element is always proportional to the level of its positive contrary at the same time. But what about the desired elevation magnitude for the positive...?

hotelambush, hitta, labcoat, anybody else: is this how you see +/-, too?

Interesting thought: I just realized that you can evaluate information levels in terms of either quantity... or quality. (*hint hint*)

(And I just realized, that if +/- works on such a gradient, then it is indeed proof of Jung's libido concept.)