There are two things I really like to learn about: parasites and the human mind. And so I was intrigued to learn about some studies that suggest that we defend ourselves from infections not only with an immune system made up of cells and antibodies, but one made up of unconscious behaviors. It’s the topic of my new column about the brain in Discovernew column about the brain in Discover. Other people can make us sick, and so perhaps we deal with them differently depending on our risk of getting sick. Take this study, from Carlos Navarrete, a psychologist at Michigan State University. He and his colleagues designed an experiment to