> There are, unsurprisingly, multiple theories about the cause. The hygiene hypothesis is one front-runner, positing that people who are “too clean” develop allergies.
This also breaks down into two versions with very different implications:
1. Not enough exposure to potential threats to toughen up an immune system.
2. Not enough exposure to benign "old friends" we co-evolved with that are almost symbiotic.
This also breaks down into two versions with very different implications:
1. Not enough exposure to potential threats to toughen up an immune system.
2. Not enough exposure to benign "old friends" we co-evolved with that are almost symbiotic.