Causality-Increase-Decrease-MIT-Credit-NNever-Happened Models

These models and simulations have been tagged “Causality-Increase-Decrease-MIT-Credit-NNever-Happened”.

If I could understand the logic in how '+' and '-' arrows work in this diagram, I would be thrilled! This would solve a lot of confusion I experience with many other diagrams. If I understand it here, I can understand it there. I copied this diagram exactly, the first one, from the MIT paper that
Causality Increase Decrease MIT Credit NNever Happened
If I could understand the logic in how '+' and '-' arrows work in this diagram, I would be thrilled! This would solve a lot of confusion I experience with many other diagrams. If I understand it here, I can understand it there.

I copied this diagram exactly, the first one, from the MIT paper that is the basis for Gene's diagram, "Credit Never Happened..." found in segment 5, Thinking Systemically.

I also copied the Note, exactly, from the bottom of that first diagram so I could study it to figure out these damn arrows and their confusing (to me) plus and minus labeling.
Trying to Understand '+' and '-'
Mike Blackstone