How the immune system can alter our behavior

Simply the smell of seafood can make those with an allergy to it violently ill -- and therefore more likely to avoid it. The same avoidance behavior is exhibited by people who develop food poisoning after eating a certain meal. Scientists have long known that the immune system played a key role in our reactions to allergens and pathogens in the environment, but it was unclear whether it played any role in prompting these types of behaviors towards allergic triggers.