Category Structure and Typicality Effects
Masako Jitsumori · Oxford University Press eBooks · 2009
The ability of organisms to categorize objects may enable them to learn about their environment economically, with a decrease in the amount of information that they would otherwise have to acquire. Concepts allow the large number of stimuli to be reduced to a small number of categories. Categorization allows human and nonhuman animals to cope with the stimulus variability that exists in the environment. Numerous studies have shown that animals, particularly pigeons, can classify photographs that contain a particular type of natural object. However, little attention has been given to the relational structure of stimuli that enables animals to classify complex visual stimuli in accordance with the human taxonomies of real-world objects. This chapter reviews contemporary categorization studies in nonhuman animals, focusing on category structure and on theoretical issues surrounding the learning of prototype categories. The prototype effects shown by pigeons can be explained without the need to posit prototype-abstraction process.