Automatic and Controlled Processes in Social Cognition 269will be possible for the perceiver to engage in controlled
processing. Without sufficient mental resources, automatic
mental processes are presumed to operate in an unchecked
manner, and it is difficult or impossible for perceivers to im-
pose their will and exercise control over the workings of their
own minds. Early theorizing about attentional capacity as-
sumed a simple, unitary structure to the mental resources that
are used in conscious, controlled information processing.
However, advances in cognitive neuroscience have made it
possible to identify a more differentiated set of working mem-
ory resources (e.g., Roberts, Robbins, & Weiskrantz, 1998).
Baddeley (1998) proposed that there are three principal facets
to working memory, each with a limited capacity for holding
information: a phonological buffer, a visuospatial sketch pad,
and a central executive. It is the latter resource that is most im-
portant to social-cognitive theorizing, because it is the central
executive that governs the conscious planning, execution, and
regulation of behavior. When these executive resources are in
ample supply, individuals are generally able to exercise a
considerable degree of control over their conscious thought
processes and behavioral responses; when these finite re-
sources have been usurped by other ongoing processes, how-
ever, the resulting executive dysfunction can put perceivers in
the position of failing to produce intended patterns of thinking
and responding. Under this circumstance, thought and action
will be dictated more by potent automatic reactions than by the
force of the conscious will.
Research on mental control has undergone a dramatic resur-
gence in the past decade (for an excellent sampling of research
topics, see Wegner & Pennebaker, 1993). Wegner’s research
on thought suppression has been a major impetus for this ex-
plosion of research attention (e.g., Wegner, 1994; Wenzlaff &
Wegner, 2000). In this research, the prospects for mental self-
control have been investigated by providing participants with a
self-regulatory injunction to consciously pursue (e.g.,don’t
think about white bearsordon’t be sexist). Success is measured
simply by the number of times the unwanted response is gen-
erated, and success rates can be considerable—provided that
the person has ample attentional resources. However, if a cog-
nitive load is imposed on the person (e.g., a secondary task
must be completed simultaneously, such as rehearsing an
eight-digit number), not only are unwanted responses likely to
emerge, but they are also likely to occur with even greater fre-
quency than they would if the person had never tried to sup-
press them in the first place (i.e., arebound effect).
Wegner (1994) proposed a theoretical account for this
state of affairs; his account rests on the assumption that men-
tal control reflects the operation of two separate processes. A
monitoring processis responsible for checking to see whether
undesired responses (e.g., sexist thoughts) are occurring. If it
should detect such responses, anoperating processis trig-
gered that serves to squelch the unwanted response by finding
an acceptable substitute response (e.g., thoughts about a tar-
get’s occupation rather than her gender). Crucial to his model
are two additional assumptions. First, the monitoring process
can do its work in a relatively automatic manner, but must of
necessity keep active in memory (even if only at a relatively
low level) a representation of the undesirable response so that
it can be recognized if it should appear. Thus, the monitoring
process ironically keeps an unwanted thought or response
salient in the perceiver’s mind. This recurrent activation of
the undesired target stimulus is not a big problem, so long as
the operating process can counteract the unwanted response
whenever it does exceed the threshold necessary for con-
scious awareness. However, a second assumption of the
model is that the operating process is relatively effortful and
requires sufficient attentional resources. Hence, if these re-
sources are being depleted by other tasks (e.g., rehearsing a
digit string), the enhanced accessibility created as a byprod-
uct of the monitoring process cannot be effectively checked,
and the stage is set for rebound effects.
These assumptions have been explored in the domain of
stereotype suppression by several researchers. In the contem-
porary social world, it has become largely taboo to respond to
many stigmatized social groups in terms of negative stereo-
types and prejudices that have historically been prevalent. In
the previous section, we reviewed several pieces of evidence
suggesting that stereotypes can exert numerous automatic ef-
fects on information processing. If so, what are the prospects
for success when perceivers strive to follow the dictates of
cultural injunctions against thinking discriminatory thoughts
about these stigmatized groups? In an initial demonstration,
Macrae, Bodenhausen, Milne, and Jetten (1994) showed
that individuals who strive to prevent stereotypical reactions
from entering their thoughts can succeed as long as they are
actively pursuing that objective. However, consistent with the
implications of Wegner’s ironic model of mental control, this
process rendered the unwanted thoughts hyper-accessible,
and Macrae et al. found that after the suppression motivation
had dissipated, rebound effects emerged when subsequent
members of the stereotyped group were encountered. That is,
participants reported even more stereotypical reactions to the
subsequent group members than did individuals who had
never engaged in any previous stereotype suppression. These
findings confirm that intentionally suppressing stereotypes
ironically involves repeatedly priming them, albeit at rela-
tively low levels—and this in turn renders the stereotypes all
the more accessible. If the operating process that is commis-
sioned to direct attention away from unwanted thoughts
should be compromised either by the imposition of a cognitive