Prototype theory

In cognitive psychology, prototype theory describes how people categorize things. A "prototype" is considered a central member (or the central member) of a category.
==Contrast with the classical theory==
The classical theory of concepts views concept formation as definitional. That is, concept x is composed of simpler concepts that describe necessary and sufficient conditions for being a member of x. For example, a triangle may be defined as a "three-sided polygon" where a shape is a triangle if and only if it satisfies the condition of being both a polygon and being three-sided. However, the classical theory came to be seen as increasingly insufficient during the 20th century. Protracted disagreements over definitions led to dissatisfaction with classical theory in philosophical circles, and the theory also failed to explain new empirical results in psychology.
Prototype theory was developed as an alternative to the classical theory. Categories and concepts, according to this theory, are probabilistic rather than definitional in nature. They are radially structured, with some members more central than others. The items in a category generally have graded degrees of membership. For example, sparrow is more central to the category bird than are kiwi or emu, even though the last two examples are just as much members of the Linnaean class Aves as the first one. When asked to name an example member of a given category, respondents most often mention prototypical members of that category. The boundaries and central members of a category may change over time as a person takes in more exemplars.
==Early research==
Taking inspiration from Ludwig Wittgenstein's concept of family resemblance, Eleanor Rosch developed prototype theory during the 1970s.Eleanor Rosch and Carolyn B. Mervis. Family Resemblances: Studies in the Internal Structure of Categories. Cognitive Psychology 7, 573-605 (1975) Rosch first tested her ideas among the Dani people of New Guinea. The Dani have only two concepts of color in their language. Rosch selected focal colors as "natural prototypes" to teach to the Dani participants in her experiments. She found that the participants learned new color concepts much faster when these natural prototypes were used.Eleanor H. Rosch. Natural Categories. Cognitive Psychology 4, 328-350 (1973)
==Basic level categories==
Categories exist at various levels, described as basic, subordinate, or superordinate. The basic level is not the "lowest" level in a hierarchy, but may be considered the most convenient mid-level entry point to a set of related categories. The basic level is neither too specific nor too general. Visualizing any given basic level category is easily possible, using a generalized prototypical member. Subordinate categories are more specific than their basic category, and superordinate categories more general. A superordinate category may be difficult to visualize in terms of a single example. For example, chair is a basic category, with subordinate categories including rocking chair, recliner, Windsor chair, etc. Chair belongs to the superordinate category furniture. When asked what they are sitting on, most people will respond using the basic category, "a chair," rather than a specific type of chair. Very seldom will anyone respond, "I am sitting on furniture."
==Criticism==
Hofstadter & Sander (2013) don't dispute graded categorization, but point out that on any level the categorization is always fuzzy and not at all as nicely structured as proposed by the Prototype Theory. No level of scrutiny seems to bring someone closer to understanding, since all the parts are themselves concepts with fuzzy outlines:
==Bibliography==
* Lakoff, George (1987): Women, fire and dangerous things: What categories reveal about the mind, London.
* Rosch, Eleanor (1973): "Natural categories", Cognitive Psychology 4, 328-350.
==References==
Category:Philosophy
Category:Science
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