[[File:SCT comparative context.JPG|thumb|right|300px|alt= Variation in self-categorization as a function of comparative context.| Figure 2. Variation in self-categorization as a function of comparative context. In Context 1 Amy and Beth self-categorize in terms of lower-level personal identities that accentuate their differences from each other. However, in Context 2 the comparative is extended to include more different others (here men), and Amy and Beth are now more likely to define themselves in terms of a higher-level social identity. They hence appear more similar to each other. The main theoretical point here is that as comparative context is extended, people tend to self-categorize at a more inclusive, higher level of abstraction.<ref name="Haslam, et al. (2011)."/>]]Comparative fit is determined by the meta-contrast principle—which states that people are more likely to believe that a collection of stimuli represents an entity to the degree that the differences between those stimuli are less than the differences between that collection of stimuli and other stimuli.<ref name="McGarty, C (1999)."/><ref name="Turner, J. C. et al. (1987)."/><ref name="Turner, J. C. et al. (1994)."/> For predicting whether a group will categorize an individual as an ingroup or outgroup member, the meta-contrast principle may be defined as the ratio of the average similarity of the individual to outgroup members over the average similarity of the individual to ingroup members. The meta-contrast ratio is dependent on the context, or frame of reference, in which the categorization process is occurring.<ref name="Turner, J. C. (1999)">Turner, J. C. (1999). Current issues in research on social identity and self-categorization theories. In N. Ellemers, R. Spears, & B. Doosje (Eds), Social identity: Context, commitment, content (pp. 6-34) Oxford, UK. Blackwell.</ref> That is, the ratio is a comparison based on whichever stimuli are cognitively present. For example, if the frame of reference is reduced such that potential outgroup members are no longer cognitively present, ingroup members regard the individual as less similar to the group and are less likely to categorize that individual as belonging to that group.
