Concepts as Implicit Theories

Psy315 - Class 33

(This page last updated 30 March, 2009.)

The previous two pages reviewed three possible ways of representing concepts and categories. This page reviews a fourth possibility.

4. Implicit Theories

 Keil (1986)

• Skunk transformed to look like raccoon.
• Toaster transformed to look and work like coffee pot.
• Preschool children report that transformed skunk is still skunk, but that transformed toaster is now coffee pot.
• For raccoons and skunks, their history is important for deciding how to categorize them. This is not true for coffeepots.

Essential Properties

• Some categories (raccoons, dollar bills) seem to be defined by something other than just resemblance to prototype or exemplars.
• There seem to be some "essential properties" (raccoon genes, being printed by the government) that are necessary to be a member of that category.
• To know what properties are essential for a particular category, we need a theory about what defines that category and how it relates to other category.
• Part of the mental representation of a category can be an implicit theory.

The Role of Implicit Theories in Defining Some Categories

• Your implicit theory about bachelors tells you that they should have other properties besides being male and unmarried.
• Your implicit theories about animal species tells you that they are ultimately defined not by typicality, but by their genetic material.
• Your implicit theory of money tells you that a dollar bill is legally valid only if it is issued by the government.
• Your implicit theories about manufactured objects tells you that they are defined mainly by their ability to perform a specific function.

Advantages of Implicit Theories

• In many cases, your mental representation of a concept depends on your implicit theory of that concept and how it relates to other concepts.
  • Explains why concepts for "natural kinds" such as animal species work differently from concepts for manufactured objects.
• Does this leave any role for prototypes or exemplars?
  • Prototypes and exemplars are very useful for quickly identifying and categorizing things.
  • We can use them as a heuristic for categorization.
  • Our implicit theories can tell us when it is appropriate for us to use prototypes or exemplars, and when it is not.
  • They can also tell us which properties are most important to consider when comparing against a prototype or exemplar.

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