I've been reading CFAR Handbook's chapter about Againstness. The chapter's idea is that when your sympathetic nervous system (SNS) is dominant over parasympathetic nervous system (PSNS), your introspection is impaired and you tend to be less rational, hence you should learn how to know which system is currently dominant and also learn to switch to PSNS dominance.

They provide the following table of how your body, mind, and behaviour change depending on which system is dominant

In order to learn to know where you are on SNS-PSNS spectrum they recommend observing yourself in different situations, determine which system is dominant, and try to find patterns (e.g., maybe after doing physical exercise your SNS is usually dominant).

Well, I tried observing myself and figuring out which nervous system is active, and about 70% of the times I can't determine it. I ask myself questions like "Do I feel joy?", "Am I at peace?", "Are my muscles tense?", "Does my skin feel like flushed?", "Is my breathing shallow, or slow and in belly?". More often than not I can't answer these questions. And it doesn't help that there's no easy way to calibrate by observing the ground truth.

If there are people here who can determine which of your two nervous systems is dominant, how do you do it? Any tips for me?

Also, sometimes I get signals from my body that don't fit in this framework. When it's time for me to go to sleep but I don't do it, after a while my awareness and introspective clarity become impaired, I feel both energized and lacking energy at the same time, I fill like my system 2 (as in Kahneman's two systems) doesn't turn on a lot, and I get impatient. What happens with SNS and PSNS at this time? I don't know.