Journal of Communication ISSN 0021-9916 ORIGINAL ARTICLE The Differential Susceptibility to Media Effects Model Patti M. Valkenburg & Jochen Peter Amsterdam School of Communication Research ASCoR, University of Amsterdam, Amsterdam, the Netherlands In this theoretical article, we introduce the Differential Susceptibility to Media Effects Model (DSMM), a new, integrative model to improve our understanding of media effects. The DSMM organizes, integrates, and extends the insights developed in earlier microlevel media-effects theories. It distinguishes 3 types of susceptibility to media effects: dispositional, developmental, and social susceptibility. Using the analogy of a mixing console, the DSMM proposes 3 media response states that mediate media effects: cognitive, emotional, and excitative. The assumptions on which the DSMM is based together explain (a) why some individuals are more highly susceptible to media effects than others, (b) how and why media influence those individuals, and (c) how media effects can be enhanced or counteracted. doi:10.1111/jcom.l2024 The past decades have witnessed thousands of empirical studies into the cognitive, emotional, attitudinal, and behavioral effects of media on children and adults (Potter & Riddle, 2007). The effect sizes that have been found for most outcome variables are consistent, albeit small to moderate at best. For example, recent meta-analyses on the effects of violent videogames on aggression have yielded effect sizes ranging from r = .08 (Ferguson & Kilburn, 2009) to r = .19 (Anderson et al., 2010). Likewise, studies of the effects of advertising on materialism have revealed small to moderate effects sizes (Buijzen & Valkenburg, 2003). However, for other outcome variables, media effects are less consistent or even conflicting. This is the case for research on the effects of social media on social connectedness (Valkenburg & Peter, 2011), and for studies of media effects on ADHD and ADHD-related behaviors, such as attention problems (Kirkorian, Wartella, & Anderson, 2008). Although the small and inconsistent effects reported are not unique to media-effects research, it is important to investigate whether they are truly small or an invalid representation of the underlying effect sizes in the population. Invalid small and inconsistent media effects can be due to methodological weaknesses, in particular unreliable media use measures, which may lead to the attenuation of effect sizes. Invalid small and inconsistent effects can also result from a suboptimal Corresponding author: Patti M. Valkenburg; e-mail: p.m.valkenburg@uva.nl Journal of Communication 63 (2013) 221-243 © 2013 International Communication Association 221 Differential Susceptibility to Media Effects Model P. M. Valkenburg & J. Peter conceptualization of media effects, a position we take in this article. In our view, a possible cause of the small and inconsistent media effects is that insights of existing media-effects theories have not been systematically evaluated and synthesized in a comprehensive media-effects model. The overall aim of this article is to organize the media-effects literature in order to achieve more conceptual coherence about the role of media variables (media use, media processing) and nonmedia variables (individual-difference variables, social context) in media effects research. Although media-effects theories typically include media and nonmedia variables in their conceptions, there is still insufficient consensus about how to conceptualize the roles of and relationships between these variables. On the basis of a review of existing media-effects theories, we introduce a new, integrative model to better understand the roles of, and relationships between, media and nonmedia variables in media-effects theories. The model, which we have named the Differential Susceptibility to Media Effects Model (DSMM), focuses on microlevel media effects. Microlevel media-effects theories base their inferences on observations of the individual media user. The DSMM builds upon earlier individual-level media-effects theories that have been identified as well-cited theories in the reviews of Bryant and Miron (2004), Potter and Riddle (2007), and Potter (2012). These theories are Bandura's (1986) Social Cognitive Theory; Berkowitz' (1984) Neoassociationist Model and other accounts of Media Priming (Roskos-Ewoldson & Roskos-Ewoldson, 2009); Klapper's (1960) Selective Exposure Theory; Lang's (2009) Limited Capacity Model of Motivated Mediated Message Processing; Markus and Zajonc's (1985) Orientations-Stimulus-Orientations-Response (O-S-O-R) Model and its extensions in communication research (e.g., Communication Mediation Model; McLeod, Kosicki, & McLeod, 2009); Petty and Cacioppo's (1986) Elaboration Likelihood Model; Katz, Blumler, and Gurevitch's (1973) Uses-and-Gratifications Theory; and microlevel variants of Cultivation Theory (Shrum, 2009). It also builds upon some recent well-cited media-effects theories, in particular Slater's (2007) Reinforcing Spiral Model, and upon several theories that have been used to understand media effects on youth: Anderson and Bushman's (2002) General Aggression Model, Potter's (1999) Lineation Theory, and Steele & Brown's (1995) Media Practice Model. Throughout this article, we refer to media effects as the deliberative and non-deliberative short- and long-term within-person changes in cognitions, emotions, attitudes, beliefs, physiology, and behavior that result from media use (see Potter, 2011, 2012, for definitions and more elaborate conceptualizations of these six types of media effects). Media use, if not indicated otherwise, is defined broadly as the intended or incidental use of media types (e.g., TV, computer games), content (e.g., entertainment, advertising), and technologies (e.g., social media). Organizing existing media-effects theories along five global features The aim of this article is to achieve more conceptual coherence about the role of media variables and nonmedia variables. While reviewing the existing microlevel 222 Journal of Communication 63 (2013) 221-243 © 2013 International Communication Association P. M. Valkenburg & J. Peter Differential Susceptibility to Media Effects Model media-effects theories, we observed that these theories could be organized along the following five global features that address the relationships between media and nonmedia variables. Conditional media effects Models that propose conditional media effects share the notion that effects of media on cognitions, emotions, attitudes, beliefs, physiology, and behavior can be enhanced or reduced by individual-difference (e.g., gender, temperament, developmental level) and social-context variables (e.g., parents, peers). These variables are moderators, that is, variables that modify the direction and/or strength of the effect of media use on a given outcome. If a moderator is valid, a media effect is conditional, which means that it does not equally hold for all media users. An example of a conditional media-effects model is Bandura's (2009) Social Cognitive Theory in which preexisting self-efficacy is conceptualized as a moderator of media-promoted behavior. Similarly, in Petty and Cacioppo's (1986) Elaboration Likelihood Model, need for cognition, the tendency to enjoy effortful information processing, is seen as a moderator of media effects. Finally, Klapper's (1960) Selective Exposure Theory, Potter's (1999) Lineation Theory, Uses-and-Gratifications Theory (Rubin, 2009), and Slater's (2007) Reinforcing Spiral Model recognize that individual-difference and social-context factors interact with media effects. Like these earlier theories, the DSMM rejects universal media effects and acknowledges that nonmedia variables moderate media effects. Indirect effects type I: media use as a mediator The media-effects literature typically conceptualizes three types of indirect effects. The first type considers media use as a mediator between individual-difference variables and outcomes of media use (Slater, 2007). A mediator, or intervening variable, is a variable that provides a causal link between an independent and a dependent variable. In indirect-effects type I models, media use is predicted by individual-difference variables, such as gender, developmental level, and temperament. Media use, in turn, provides the causal connection between these individual-difference variables and the outcomes of interest. For example, teenagers high in sensation seeking are predisposed to use violent media, which in turn will stimulate their aggressive behavior. Examples of such models are Anderson and Bushman's (2002) General Aggression Model, Bandura's (2009) Social Cognitive Theory, Klapper's (1960) Selective Exposure Theory, McLeod et al.'s (2009) Communication Mediation Model, and Slater's (2007) Reinforcing Spiral Model. The DSMM also conceptualizes this type of indirect effect. Indirect effects type II: media response states as mediators Models that conceptualize this type of indirect effect consider the mental and physiological processes that occur during media use as a mediator between media use and outcomes. For example, exposure to an arousing news item may stimulate viewers' attention and physiological arousal, which in turn stimulate their recall of, Journal of Communication 63 (2013) 221-243 © 2013 International Communication Association 223 Differential Susceptibility to Media Effects Model P. M. Valkenburg & J. Peter or attitudes toward, the news issue. Many media-effects theories recognize that the processes that occur while using media are the causal links between media use and media effects. These processes are named differently in various theories. They have been named message processing (Lang, Potter, & Bolls, 2009; Petty, Brinol, & Priester, 2009), exposure states (Potter, 2009), reception-activity orientations (McLeod et al., 2009), internal states (Anderson & Bushman, 2002), selective perception (e.g., Klapper, 1960), and online judgments (Shrum, 2009). Similar to these theories, the DSMM acknowledges that the mental and physiological processes that occur during media use mediate media effects. We call these processes media response states. Indirect effects type III: media effects as mediators Models that include media effects as mediators recognize that media effects themselves can be the cause of other media effects. These effects, which we call mediating media effects, provide the underlying mechanisms of (or causal route to) second-order media effects. The difference between mediating media effects and media response states is that media response states typically occur during media use. Mediating media effects can start during media use but they last beyond the media use situation. For example, adolescents' use of social media can enhance their intimate self-disclosure to friends (mediating media effect), which in turn influences their perceived quality of these friendships (second-order media effect; Valkenburg & Peter, 2009). Likewise, informational media use stimulates interpersonal discussion (mediating media effect), which in turn enhances participatory behavior (second-order media effect; Social Cognitive Theory, Bandura, 2009; Communication Mediation Model, McLeod et al., 2009; Two-Step Flow of Communication Theory, Lazars-feld, Berelson, & Gaudet, 1944). The DSMM also recognizes mediating media effects. Transactional media effects Finally, models that conceptualize transactional media effects propose that outcomes of media use also influence media use. Transactional media-effects models consider media use and media effects as parts of a reciprocal over-time influence process, in which the media effect is also the cause of its change (Früh, & Schönbach, 1982). For example, adolescents' use of violent media may increase their aggressive tendencies, which may then stimulate their violent media use (Slater, 2007). Media-effects theories that include transactional effects are Anderson and Bushman's (2002) General Aggression Model, Bandura's (2009) Social Cognitive Theory, Slater's (2007) Reinforcing Spiral Model, and Steele and Brown's (1995) Media Practice Model. The DSMM also recognizes transactional media effects. Synthesizing existing media-effects theories While reviewing the existing microlevel media-effects theories, we noted a lack of consensus about what the media-effects process exactly entails. Some media-effects 224 Journal of Communication 63 (2013) 221-243 © 2013 International Communication Association P. M. Valkenburg & J. Peter Differential Susceptibility to Media Effects Model theories focus predominantly on one type of indirect effects, for example on our indirect effects type I, in which media use is conceptualized as a mediator (e.g., Klapper, 1960; Slater, 2007). Others conceptualize indirect effects type I and type II (e.g., O-S-O-R model, Markus &Zajonc, 1985; Neoassociationistic Model, Berkowitz, 1984). Still others conceptualize all three types of indirect effects (Communication Mediation Model, McLeod et al., 2009). Theories that focus on indirect effects, and the research that follows from it, typically devote less attention to conditional effects (e.g., Sotirovic & McLeod, 2001; but for exceptions, see e.g., Holbert, 2005; Slater, 2007). In our view, however, we need models that systematically conceptualize conditional and indirect media effects. Only if we investigate both types of effects can we truly understand (a) which individuals are more highly susceptible to media effects than others, (b) how and why media use influences those individuals, and (c) how media effects can be enhanced or counteracted. In the media-effects literature, there are some more comprehensive models that do conceptualize conditional and indirect effects. Both the General Aggression Model (Anderson & Bushman, 2002) and the Elaboration Likelihood Model (Petty et al., 2009) contain four of the five features of media-effects theories, but do not include media effects as mediators (General Aggression Model) or transactional effects (Elaboration Likelihood Model). The only theory that, to our knowledge, encompasses all five features of media-effects theories is Bandura's (2009) Social Cognitive Theory. Unfortunately, Social Cognitive Theory has only been scantly integrated in the media-effects literature (Pajares, Prestin, Chen, & Nabi, 2009). Social Cognitive Theory is a comprehensive theory with broad concepts that are related to one another in complex ways. As a result, it is often difficult to distill the meanings of its concepts and their exact links to other concepts, which might have hindered the empirical testing of its underlying mechanisms. However, due to the high potential of Social Cognitive Theory to understand media effects, the DSMM attempts to clarify some of its propositions, and, by doing so, stimulate its integration in media-effects research. While reviewing earlier media-effects theories, we also observed a lack of consensus about the role of, and relationships between, media and nonmedia variables. In some theories, specific media variables are considered as mediators between media use and effects. In other theories, these same variables are conceptualized as moderators. For example, some theories consider media response variables, such as identification with characters and reality perception, as a mediator between media use and media effects (e.g., Transportation Theory; Green, Brock, & Kaufman, 2004; Extended Elaboration Likelihood Model, Slater, & Rouner, 2002). In other theories and empirical research, these same variables are conceptualized as moderators (e.g., Cultivation Theory, Shrum, 2006; Social Cognitive Theory, Bandura, 1986). An important aim of the DSMM is to more precisely identify the roles of and relationships between media and nonmedia variables and to specify the conditions under which these variables should be seen as a moderator or as a mediator in the media-effects process. Journal of Communication 63 (2013) 221-243 © 2013 International Communication Association 225 Differential Susceptibility to Media Effects Model P. M. Valkenburg & J. Peter The DSMM: four related propositions The DSMM consists of an integrated set of four related propositions that set forth the relations between the media and nonmedia variables that have been proposed in earlier media-effects theories. The DSMM recognizes and integrates all five features of earlier media-effects theories that we distinguished. The four propositions that follow involve only extensions to or specifications of these earlier theories. These propositions will particularly focus on conditional media effects, indirect effects type II (media response states as mediators), and transactional media effects. Conditional media effects: three types of susceptibility An important aim of several earlier media-effects theories has been to identify the various conditions under which media effects are more or less present. Unfortunately, the literature has not been consistent in its conceptualization of the conditional variables that affect the media-use-and-effects relationship. The DSMM conceptualizes three broad types of conditional variables, which we name differential-susceptibility variables. These differential-susceptibility variables are all preexisting; they are assessable before the media use situation. Proposition 1 is visualized in the left-hand square in Figure 1. Proposition 1: Media effects are conditional; they depend on three types of differential-susceptibility variables: dispositional, developmental, and social. Dispositional susceptibility is defined as all person dimensions that predispose the selection of and responsiveness to media, including gender, temperament, personality, cognitions (e.g., scripts and schemata), values, attitudes, beliefs, motivations, and moods. Some of these dimensions (e.g., personality, temperament) are more stable across time and situations than others (e.g., mood, motivations; Gray & Watson, [ Proportion 1 DiipůSiliĎrtíil I OavctopmofiUil [ Sůíinl L Proposition 2 Pfůp QslUun 3: ftfild 1 (predictors) use Prop ail Hon 3: Rolo 2 (moderators) Rosjhwisc stales.: cognitive. omoLonai, excitative Madia effects Proposition A \ Proposition 1: Media offocls depend on tfir