It doesn’t seem to be true in any literal, biological sense. I don’t recall that they had concrete cites for a lot of their theses, and this one doesn’t even define the units of measurement (yes, glucose, but no comments about milligrams of glucose per decision-second or anything), so I don’t know how you would really test it. I don’t think they claim that it’s actually fixed over time, nor that you can’t increase it with practice and intent.
However, like much of the book, it rings true in a “useful model in many circumstances” sense. You’re absolutely right that arranging things to require low-momentary-willpower can make life less stressful and probably get you more aligned with your long-term intent. A common mechanism for this, as the book mentions, is to remove or reduce the momentary decision elements by arranging things in advance so they’re near-automatic.
It doesn’t seem to be true in any literal, biological sense. I don’t recall that they had concrete cites for a lot of their theses, and this one doesn’t even define the units of measurement (yes, glucose, but no comments about milligrams of glucose per decision-second or anything), so I don’t know how you would really test it. I don’t think they claim that it’s actually fixed over time, nor that you can’t increase it with practice and intent.
However, like much of the book, it rings true in a “useful model in many circumstances” sense. You’re absolutely right that arranging things to require low-momentary-willpower can make life less stressful and probably get you more aligned with your long-term intent. A common mechanism for this, as the book mentions, is to remove or reduce the momentary decision elements by arranging things in advance so they’re near-automatic.