Carving Up the Social World with Generics

Generics are sentences such as “tigers are striped,” “lions have manes,” and “mosquitoes carry West Nile virus.” Generics express generalizations, but unlike quantified statements, generics do not carry information about howmany members of the kind or category have the property. For example, if asked “how many ravens are black?” one could reply “all [or some, or most, etc] ravens are black,” but one cannot felicitously reply with the generic “ravens are black” (Carlson 1977). Generics have long been the subject of considerable discussion in linguistics and philosophy, as they, unlike quantified statements, are extremely difficult to analyze truth conditionally (e.g., Carlson, 1977; Carlson and Pelletier, 1995; Cohen, 1996, 2004; Greenberg, 2003; Lawler, 1973; Leslie, 2007, 2008; Pelletier and Asher, 1997). As a simple illustration of part of the difficulty, consider the generics “lions have manes” and “lions are male”—the former would seem true, while the latter is false, even though of course it is only ever male lions that have manes. Similarly, we might note that “mosquitoes carry West Nile virus” is true, while “books are paperbacks” is false, even though over eighty percent of books are paperbacks, yet only one percent of mosquitoes carry West Nile virus.