Potentially controversial take: Unhappiness and intelligence are both correlated with deep rumination. Deep rumination over negative things is a hallmark of de

Potentially controversial take: Unhappiness and intelligence are both correlated with deep rumination. Deep rumination over negative things is a hallmark of depression, and deep rumination over a hard problem is a hallmark of intelligence. I suspect the "deep rumination" instinct can go astray, causing deep-set unhappiness.