As ideas about the nature of categories have developed, genre theory has developed in parallel. It has moved from attempts to define genre categories in terms of necessary and sufficient conditions (e.g. the neo-Aristotelians Crane and Olson), to attempts to look at genre in terms of the Wittgensteinian concept of "family resemblances" (e.g. Fowler's Kinds of Literature). But progress in this direction has stalled, due to the lack of any rigorous account of the nature of family resemblances. Genre critics now prefer to consider how socio-historical context shapes the way genres are used and evolve. Emphasis now rests on the irreducibility of the individual work to its class, the openness of the class, and change over time.
The cognitive-scientific study of categories offers a way out of this impasse. It recognizes precisely these factors in categorization generally, and proposes powerful theories to explain them. The research of Eleanor Rosch and her colleagues in the 1970s demonstrated "prototype effects" in categorization. People learn categories from prototypical examples, not from abstract rules or qualities, and they think about categories by referring to such examples. Categories are not internally unstructured; rather some members are prototypical or "central" or representative of the category, while others are marginal or peripheral.
The relevance to literary genre is striking. Genre critics and literary historians tend to identify genres by reference to sequences of works, and classify works by their place in a historical series. The point is evident with such formally chaotic genres as the novel and Menippean satire. Even here, writers emulate but alter canonical models, to produce variations on a form. Authorial and critical practice demands an approach that is sensitive to the role of exemplars in thought and in history. If literary genres are best described in terms of prototypicality, they are then best explained in terms of a theory that was designed to account for prototype effects--George Lakoff's theory of idealized cognitive models.
Cognitive linguists, following Lakoff's lead, have applied prototype theory to aspects of meaning and form in language. In order to explain "prototype effects" in metaphorical, lexical, and syntactic constructions , Lakoff proposes a theory of conceptual structure in which Idealized Cognitive Models are the basis of thought. ICMs can define category structure, central members, and principles of extension.
A cognitive approach to literary genres can start by attempting to characterize generic features as much as possible in terms of Lakoff's propositional, image-schematic, metonymic and metaphoric models. Such a framework would set the stage for explanations of generic histories in prototype-and-extensions terms.
We can begin to see more precisely how schematic models would figure in this project by exploring how one kind of model can characterize one kind of generic feature. Models of the "script" or "scenario" kind can inform schematizations of literary plots in the early English novel and in film noir, and such plot-schemas motivate other features of these genres through mappings to conventional metaphors that relate symbols to themes.