Living Reference Work Entry

Encyclopedia of Evolutionary Psychological Science

pp 1-4

Date: Latest Version



Allergic reactions


An excessive pathological reaction of the immune system towards environmental substances, such as foods and pollens, that are tolerated by the immune system of nonallergic individuals.


Allergies have become increasingly prevalent over recent decades, particularly in the West. As a consequence, interest has grown regarding why such a phenomenon exists in the first place, especially given the risk of experiencing a potentially fatal allergic reaction called anaphylaxis (Gross 2015). Early explanations typically viewed allergies as merely immunological errors. However, the evolutionary persistence of allergic capability suggests that it has an adaptive value for the host, of which exerted a strong enough positive selection pressure to outweigh the physiological costs and risk of fatality. Margie Profet became a notable theorist for why allergies evolved with her controversial hypothesis regarding what this benefit of allergies may have been.

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