My mind keeps recalling this paragraph I read the other day, unsure of its conclusion:

"Survival in a time of adversity forged our brains into a persistent mould. Professor Seligman says: "Because our brain evolved during a time of ice, flood and famine, we have a catastrophic brain. The way the brain works is looking for what's wrong. The problem is, that worked in the Pleistocene era. It favoured you, but it doesn't work in the modern world."

Elsewhere in the article, someone asks: Has anyone found a causal link between happiness and health?