The COVID-19 pandemic is a grim reminder that infectious diseases have been a danger throughout human history–so much so that the threat of infection has actually helped shape human evolution. Disgust, wariness of strangers, cultural norms around food and cleanliness–all of these behaviors may have evolved at least in part to keep us safe from infectious disease. Researchers call this suite of protective mechanisms the behavioral immune system. University of British Columbia psychologist Mark Schaller, PhD, who coined that phrase, discusses the origins of the behavioral immune system and how behaviors that evolved to protect us from diseases may not be suitable for the threats we face today. Links Mark Schaller, PhD Music Minimalist Piano w/ Cello by tyops via Freesound.org