This is a great topic to request sources for. Although I unfortunately haven't any suggestions, I hope someone who does will reply. What comes to mind is MARGINS which can perhaps help in clarifying some underlying workings of things. "Margin is the space between our load and our limits. It is the amount allowed beyond that which is needed. It is something held in reserve for contingencies or unanticipated situations. Margin is the gap between rest and exhaustion, the space between breathing freely and suffocating.

Margin is the opposite of overload. If we are overloaded we have no margin. Most people are not quite sure when they pass from margin to overload. Threshold points are not easily measurable and are also different for different people in different circumstances. We don’t want to be under-achievers (heaven forbid!), so we fill our schedules uncritically. Options are as attractive as they are numerous, and we overbook.

If we were equipped with a flashing light to indicate “100 percent full,” we could better gauge our capacities. But we don’t have such an indicator light, and we don’t know when we have overextended until we feel the pain. As a result, many people commit to a 120 percent life and wonder why the burden feels so heavy. It is rare to see a life prescheduled to only 80 percent, leaving a margin for responding to the unexpected ....." R. Swenson M.D. Its been a while since I read it. I think it may have had a slight Christian reference. But no matter ones beliefs, he makes a good point. A point I remember is that books and writing have margins because our brain needs that space to allow us to process (visually) whats on the page. If you imagine trying to read something with no margins, or cut a page, it really brings the point home. (Yes, I do realize that if we learned to read without margins in the first place it may not be a problem, but all written text in any language I have seen has margins, so it must be important.)