IMPLICIT AND EXPLICIT ATTITUDE CHANGE 697 Summary atic depiction of ou ciation activa and p implicit attitude change.We start our rev w by disc reaomnencwatation,Wcareucharimplic when a pe Causes of Implicit Attitude Change ceived as evaluative judgm ents ahout an attitude obiect that have mthe perspective of model.changes in n th associative structure or(b)a te s the Tirs rega cse as ee8oa0 frets the配 The prototypical case for when the propositional implication of an automati implicit attitud ens.&Field.2005:De Ho tion is propositions that are con Tra 2005).Cons ings of ral factors that ca or nega provide an integra ive. xhaustive review of the availabl 200;Hermans ond,2003:M.A.Olson Fazio 200120022006pe。 al)M.A.d)for eample.dev ope model. ented words nd images were inte d ith critical pairing Implicit and Explicit Attitude Chang The implicit and explicit attitudes proposed ositive US exhibited a more pos sitive valenc n Implic an C M.A.Olson and individ als as CS →m with an Implicit positive word showed a more positive implicit valence than non ed tha plicit valence in an affective priming task than when these faces wccnotasocitedtihcectrcutla did not differ from EC effects resulting from p y prese awith acou propo rmipe the ant odo as USs which in tum in cted in explicit ation cit self-esteen Summary Figure 1 provides a schematic depiction of our assumptions regarding the interplay of association activation and propositional reasoning in evaluation. We argue that implicit attitudes reflect automatic affective reactions resulting from the particular associ￾ations that are activated automatically when a person encounters a relevant stimulus. Explicit attitudes, in contrast, should be con￾ceived as evaluative judgments about an attitude object that have their roots in processes of propositional reasoning. The crucial difference between associative and propositional processes is their dependency on truth values. Whereas the activation of associations can occur regardless of whether a person considers these associa￾tions as true or false, processes of propositional reasoning are generally concerned with the validation of propositions. Thus, even though evaluative judgments are usually based on automatic affective reactions, they can also be independent of associative evaluations when the propositional implication of an automatic affective reaction is considered invalid. Such rejections may occur when the propositional evaluation implied by an automatic affec￾tive reaction is inconsistent with other propositions that are con￾sidered relevant for the evaluative judgment. In the following sections, we discuss several factors that can influence association activation and propositional reasoning, thus leading to implicit or explicit attitude change. In this context, we also provide an integrative, exhaustive review of the available evidence on implicit and explicit attitude change, which is orga￾nized according to the various mechanisms implied by the APE model. Implicit and Explicit Attitude Change The conceptualization of implicit and explicit attitudes proposed by the APE model has a number of implications for attitude change. First, changes in each kind of evaluation can be due to several processes. Second, the particular interplay of associative and propositional processes may lead to various patterns of explicit and implicit attitude change. We start our review by discussing different causes of attitude change and then provide an overview of the potential interplay of implicit and explicit attitude changes. Causes of Implicit Attitude Change From the perspective of the APE model, changes in associative evaluations may reflect either (a) an incremental change in the associative structure or (b) a temporal change in the activation of preexisting patterns (Smith, 1996). Whereas the first case involves the learning of a new evaluation, the latter case reflects the dif￾ferential activation of old evaluations that are already stored in associative memory. Changes in associative structure. The prototypical case for implicit attitude changes resulting from changes in associative structure is evaluative conditioning (EC; for reviews, see De Houwer, Baeyens, & Field, 2005; De Houwer, Thomas, & Bayens, 2001; Walther, Nagengast, & Trasselli, 2005). Consistent with this notion, several studies demonstrated changes in implicit attitudes resulting from repeated pairings of an attitude object with positive or negative stimuli (e.g., Baccus, Baldwin, & Packer, 2004; Dijk￾sterhuis, 2004; Hermans, Baeyens, Lamote, Spruyt, & Eelen, 2005; Hermans, Vansteenwegen, Crombez, Baeyens, & Eelen, 2002; Karpinski & Hilton, 2001; C. J. Mitchell, Anderson, & Lovibond, 2003; M. A. Olson & Fazio, 2001, 2002, 2006; Petty et al., 2006). M. A. Olson and Fazio (2001), for example, developed a conditioning paradigm in which several hundred randomly pre￾sented words and images were interspersed with critical pairings of positive or negative unconditioned stimuli (USs) with neutral conditioned stimuli (CSs). Results indicated that CSs paired with positive USs exhibited a more positive valence in an Implicit Association Test than CSs paired with negative USs. This finding was replicated in several follow-up studies that used a subliminal affective priming task as a dependent measure (M. A. Olson & Fazio, 2002) and pictures of Black and White individuals as CSs (M. A. Olson & Fazio, 2006). Similar results were obtained by C. J. Mitchell et al. (2003), who found that the ostensible evaluative meaning randomly assigned to meaningless nonwords was subsequently reflected in implicit eval￾uations of these nonwords assessed with an Implicit Association Test. That is, nonwords that were randomly associated with a positive word showed a more positive implicit valence than non￾words that were randomly associated with a negative word. With regard to social stimuli, Hermans et al. (2002) showed that formerly neutral faces (CS) that were associated with negative electrocutaneous stimulation (US) exhibited a more negative im￾plicit valence in an affective priming task than when these faces were not associated with electrocutaneous stimulation. It is inter￾esting to note that EC effects resulting from aversive stimulation did not differ from EC effects resulting from pairings with acous￾tically presented negative words. Hermans et al. (2005) obtained similar results using food stimuli as CSs and pleasant versus unpleasant odors as USs. With regard to implicit self-evaluations, Dijksterhuis (2004) demonstrated that subliminal EC of self-related words can change implicit evaluations of the self. In particular, Dijksterhuis found that participants exhibited a higher level of implicit self-esteem Figure 1. Schematic depiction of the interplay of association activation and propositional reasoning in explicit and implicit attitudes. Input stimuli are assumed to determine the pattern of associations that gets activated in memory (bold lines connecting dots), which in turn influences affective reactions reflected in implicit attitude measures. Processes of propositional reasoning are assumed to assess the validity of activated associations, which provides the basis for evaluative judgments reflected in explicit attitude measures. IMPLICIT AND EXPLICIT ATTITUDE CHANGE 697