The Psychology of Germs, Disease, and Disgust.

Infectious diseases and the pathogens that cause them have been a serious problem throughout human history, with millions sickened and killed each year. In the modern world, hygiene and vaccinations help us manage this threat, but we all also possesses mental and physical defenses against germs. In this talk, I will discuss the emerging thinking on a set of defensive strategies grounded in our psychology – emotions, thought processes, and actions collectively called the “behavioral immune system.” Feeling grossed out or avoidant when seeing spoiled food or sick people can help prevent infection, but these reactions also negatively affect our interactions with people, groups, and environments that in reality pose no danger. Disease-related thinking also spills over into how we see the world more generally, influencing aspects of our lives from cultural taboos to the products we buy. The psychology of germs, disease, and disgust may help us understand why.