[viach]

X -> Optimism, Optimism -> Longevity

Can't wait for a research which reveals the X.

[port11]

Being healthy, good social connections, meaningful activities, exercise, family you can depend on, etc. I wonder if the optimism is just a confounding factor, or rather just the middle man we can measure. Seems like having a good life would make one more optimistic about their prospects.

[ponector]

X is a rich family. Hard to be an optimistic person if you struggle to afford to live.