I know that whenever anybody talks about happy/sad it gets downvoted. But please hear me out.
I think that major/minor is so prevalent because as humans we tend to always be in a shifting state of happiness and sadness. The shift between minor and major creates dissonance/consonance or tension/release like a person's fluctuating emotions. Therefore understanding it helps with composition and improv.
So I was wondering if we saw the major scale as a human being, is his counter sad side (think yin/yang) considered the relative or parallel minor? I was wondering if there's any kind of music theory that touched on this topic.