[rectangletangle]

I would honestly be surprised if this kind of link didn't have at least some measurable impact, physiology is hardly decoupled (in the coding sense). It's been well established that poor mental health (loss of will to live) correlates strongly with early mortality, even when controlling for obvious variables. Though establishing the causality on that is challenging.

There are lots of strange physiological links that aren't necessarily logical, due to the imperfect nature of natural selection (it strives for the local optima and "good enough," over the global optima). For instance it's well documented that consciously smiling improves mood, even though the causality is "backwards."

[amelius]

> natural selection (it strives for the local optima and "good enough," over the global optima)

It might also optimize for the community rather than the individual, I suppose.