Why cleanliness is no longer next to godliness

Heavens above! It seems modern society may have gone too far

The hygiene hypothesis suggests that we may have overdone our obsession with cleanliness in modern society.

Washing hair

This is based on the fine balance needed to affect the benefits of adaptive immunity. 

At one end of a typical U-shaped curve, extreme dirtiness exemplifies the dangers of exposure to nasty little critters that are not conducive to good health.

This was a more likely scenario before hot and cold running water.

But the other peak of the U, extreme cleanliness, is not