typicity

Typicity is the quality or degree to which an individual instance exemplifies the defining features of a category. It describes how representative a member is of a category, as opposed to being atypical or peripheral. The concept is used across disciplines to discuss how closely something conforms to a recognized archetype or exemplar, and it is often contextual and evaluative rather than absolute.

In biology, typicity is linked to typological thinking, the historical emphasis on fixed kinds or types rather than the continuous variation seen in populations. In this usage, organisms are judged by how closely they resemble the traditional type or archetype associated with a species or higher taxon. Critics of typological thinking argue that population thinking, which emphasizes variation among individuals, provides a more accurate description of biological diversity. Typicity in this sense does not imply a sharp boundary between members, but a gradient of resemblance.

In psychology and cognitive science, typicality (often synonymously used with typicity) refers to how representative a category member is, shaping judgments, memory, and speed of categorization. Prototypical exemplars are rated as more typical and are often learned and retrieved more quickly than less typical members.

Measurement of typicity commonly relies on rating scales, reaction-time experiments, or categorization tasks. Because typicality is context-dependent and culture-specific, assessments can vary with domain, purpose, and audience. Related concepts include prototype theory, essentialism, and typology.

See also: prototype theory, typology, essentialism, population thinking, type specimen.