As a country becomes more developed, allergy rises and...

As a country becomes more developed, allergy rises and rises. And the notion there is that in the more-developed countries, you may be getting less exposure to infections and germs and other things that may stimulate your immune system in a direction other than allergy, ... The more your immune system is kept busy by exposure to germs and infections early in life, the less time it can devote to things like allergy.