Parasite-Stress Theory

Here is a theory that unsettles on first hearing: regions with historically heavy burdens of infectious disease tend toward more cautious, closed, conformity-prizing cultures — and regions where disease was rare, toward open ones. Culture, the theory says, is partly an immune system.

The logic, if true, is plain: where disease lurks, the stranger is a risk, the unfamiliar food is a risk, the broken rule is a risk. Suspicion is hygiene. Where disease is rare, openness is cheap, and cultures can afford curiosity.

Whether or not the grand theory holds, the pattern underneath it does: institutions carry the fingerprints of old dangers. Rules that look arbitrary often answer threats that no longer exist — the food law, the boundary custom, the suspicion of outsiders, each an antibody to a plague nobody remembers.

So read traditions, your own and others', with this double vision: respect the antibody — it once saved lives — and test whether the disease is still present. A culture, like a body, can die of its own immune system. Wisdom is knowing which alarms still have fires attached.