Gross and disgusting things are fascinating to Valerie Curtis. She’s a “disgustologist” who joined me on America weekend to discuss her book, “Don’t Look, Don’t Touch, Don’t Eat: The Science Behind Revulsion.” We talked about how being disgusted has helped us evolve as a species, whether different world cultures are disgusted by different things, and how disgust affects what we eat and wear and even who we love. Listen to our conversation here.