You only have to sit across the table from an exuberant interlocutor to understand that masks help slow the spread of viruses. Surely everyone has noticed that

You only have to sit across the table from an exuberant interlocutor to understand that masks help slow the spread of viruses. Surely everyone has noticed that people spit when they talk. That studies have a difficulty capturing that has more to do with how difficult good social behavior studies are.