264 Social Cognition
1980). In addition, newer approaches to mental representa-
tion have been proposed that can account for many if not
all of the same phenomena covered by schema theory, but
with a much greater degree of theoretical specificity. We turn
now to one of these alternatives to schema theory—namely,
exemplar models.
Exemplars
Generic mechanisms for mental representation (e.g.,
schemas) assume that people forge abstract or prototypical
models of reality by inducing generalities across similar,
particular instances. A major alternative to this view was
provided by exemplar models (e.g., Smith & Zárate, 1992),
which hold that social cognition is based on specific repre-
sentations of individual instances. Instead of relying on pre-
computed generalizations, perceivers are assumed to retrieve
and use sets of prior relevant and specific experiences to
guide their social information processing. Consider, for ex-
ample, how the category elderly peoplemight be represented
using the various mechanisms that have been discussed so
far. In an associative network, various attributes would be as-
sumed to be linked to the generic concept elderly people,
with varying degrees of strength. In a schematic model, the
same kinds of attributes would be assumed to be embedded
within a more elaborate conceptual model, in which causal
and other kinds of constraints provide a more integrated but
still very generic structure. In the exemplar model, it is as-
sumed that there is no abstract or generic elderly peoplerep-
resentation at all. Instead, there would be a multitude of
specific elderly persons (e.g., Grandma, the kindly pharma-
cist, the doddering Senator, etc.), each represented in terms of
how they were perceived or experienced by the individual. If
the situation requires a person to make general judgments
about elderly people, then he or she will retrieve relevant ex-
emplars at that time and render judgments based on the aver-
age features of these momentarily activated exemplars.
This example conveys several important assumptions of
the exemplar approach. First, it assumes that multiple exem-
plars can be activated in parallel at the same time. The likeli-
hood that any given exemplar will be activated depends on
the degree of its similarity to the current retrieval cues. The
most similar exemplars are the ones that tend to get activated.
Upon activation, the entire set of exemplars can then influ-
ence judgments and behavioral reactions. The assumption of
parallel processing is an important characteristic of the ex-
emplar approach. During retrieval of exemplars, many simi-
lar instances tend to be retrieved simultaneously; when an
individual makes generalizations about a concept or stimu-
lus, multiple, simultaneously active exemplars enter into the
judgment (with their implications being aggregated into a
general summary). Exemplar models thus can produce and
account for generic judgments, just as schematic models
can, and they can also account for patterns of selective atten-
tion and interpretation that were previously regarded as the
hallmark of schematic processing. As soon as a set of exem-
plars is activated, it can bias the ongoing stream of informa-
tion processing, just as a schema is assumed to do. However,
exemplar models are substantially more flexible than are
schema models, because exemplar models assume that dif-
ferent subsets of exemplars will be activated in different con-
texts, depending on the particular retrieval cues that are most
salient in each context. Whereas schemas have a fixed or sta-
tic quality and are assumed to be activated in an all-or-none
fashion, exemplar retrieval can be tuned very flexibly to the
immediate situational context. Further, the specific exem-
plars that are retrieved depend partly on recency and chronic-
ity of activation. Thus, a more recently encountered elderly
person would be more likely to be recruited into our sum-
mary representation of elderly people than would a more
temporally distant one. Inasmuch as exemplar models can
account for many of the same phenomena as can other repre-
sentational formats, yet offer a strikingly greater degree of
flexibility, they have considerable theoretical appeal.
Exemplar models are of relatively recent vintage, coming
to prominence within social psychology only in the last
decade or so; there are therefore few examples of substantive
topics that have been shaped and guided by the assumptions
of this representational mechanism. One case in which such
models have taken on particular prominence is the study of
perceptions of variability versus homogeneity in social
groups (e.g., Linville, Fischer, & Salovey, 1989). Exemplar
models provide a very natural way for thinking about how
people understand and estimate group variability. By simply
calling to mind a relevant set of exemplars, the degree of vari-
ability can be gauged directly by making across-exemplar
comparisons. Research findings confirm that exemplar-based
models are better able to account for perceptions of group
variability than can models relying on prototypic or generic
representations of groups (such as schemas; e.g., Smith &
Zárate, 1990). However, many researchers have concluded
that the most sensible assumption about the mental represen-
tation of social groups is that both specific exemplars and
more abstract summaries are important components of such
representations (e.g., Hamilton & Sherman, 1994; Park &
Judd, 1990). Various ideas have been proposed concerning
the relative prevalence and importance of each type of repre-
sentation. For example, Sherman (1996) proposed that when
representations of groups are initially being formed, they
tend to be predominantly exemplar-based—but over time,