The self-concept life cycle and brand perceptions: An interdisciplinary perspective

Consumer research has paid scant attention to the full spectrum of a consumer ’ s self-concept life cycle and its subsequent impact on brand attitude. This article presents a conceptual framework that provides the foundation for future research on how the self-concept, across its full life cycle, impacts brand attitude. The article considers the development of the self-concept from childhood to late adulthood, and integrates findings from various disciplines into a comprehensive framework. The factors in the framework affecting the self-concept are global culture, life events, as well as cognitive and desired age. The article offers six propositions to guide future research and encourage more interdisciplinary work, as well as guiding the application of a broader perspective in terms of the self-concept ’ s full life-span. Moreover, the article also presents methodological and managerial implications on how to use branding approaches that target specific consumer segments according to their self-concepts ’ life cycle.


Introduction
Research investigating how the self-concept impacts a consumer's brand perceptions and the underlying decisionmaking processes has flourished over the last few decades (Chaplin and John 2005;Mittal 2006;Reed II 2002;Sirgy 1982;Sirgy et al. 2008;Sirgy et al. 1991;. Recognizing that the self-concept is dynamic over a person's lifespan, a sub-domain in this field has evolved to investigate how a person's chronological age (herein actual age) impacts his or her self-concept and, subsequently, their brand perceptions (e.g., Chaplin and John 2005;Loroz 2004;Yoon et al. 2009). More than two decades ago, however, Demo (1992) indicated that the focus of self-concept related research had been too narrow (i.e., student samples of young adults), thus limiting the applicability of the outcomes to individuals in other life-stages. The field of psychology responded through a growing body of knowledge that considers a wider range of respondents, such as adolescents and other groups from early to late adulthood (e.g., Green et al. 2012;Lodi-Smith and Roberts 2010). Nevertheless, applications to consumer research focusing on the full spectrum of a consumer's selfconcept life cycle and, subsequently, its impact on brand perceptions, such as brand attitude, have been sparse. Focusing mainly on one phase of the life cycle, these studies have shown that differences in cognitive development, as well as neural structures, are responsible for variations in the decisionmaking processes pertaining to brands among children (Chaplin and John 2007) and individuals in late adulthood when compared to young adults (Yoon et al. 2009). Recent work by Moschis (2012) offers a theoretically rich and broad review of consumer behavior among older consumers, including implications of the self-concept, but it does not delve into the other life-stages of a consumer's self-concept.
Furthermore, the self-concept is shaped by numerous factors (e.g., global culture and life events) which are investigated in disciplines such as social psychology (e.g., Hogg and Abrams 2012;Zhu and Han 2008). Consequently, consumer researchers should also use multiple theoretical lenses to explore consumer phenomena (Pham 2013) and adopt an interdisciplinary perspective to study the self-concept across its full life cycle (McConnell 2011). Adopting a wide variety of perspectives might potentially reveal new insights into how the selfconcept impacts brand attitude. The narrow focus of selfconcept research in the consumer domain is particularly surprising, as it was established decades ago that consumers use brands as a means of self-expression (Belk 1988); this marks the self-concept as a key construct in consumer research (Aguirre-Rodriguez et al. 2012). Moreover, the number of potential consumers in various age groups (e.g., older adults) continues to grow across the globe (Hurd and Rohwedder 2010;Schwarz 2003;Szmigin and Carrigan 2001). This notion further amplifies the need for a more comprehensive understanding of how the self-concept affects brand attitude during its full life cycle. Apart from benefiting consumer researchers from a theoretical perspective, such knowledge also offers marketing practitioners insights into how to position their brands when targeting consumers from specific age segments.
This article contributes to the growing body of literature on how consumers use brands as a means of self-expression during various life-stages (Chaplin and John 2005;Loroz 2004;Yoon et al. 2009). This is accomplished through the following two objectives: First, it offers a synthesis of the previous literature on various factors that have been shown to impact the selfconcept at different life-stages. The three factors considered in the framework are: (1) global culture, (2) life events, (3) and cognitive as well as desired age. Subsequently, these factors are integrated into a conceptual framework, which offers a Bbig picture^that considers an interdisciplinary perspective on the full self-concept life cycle (from childhood to late adulthood) and how it impacts brand attitude. Second, the article provides six research propositions that consider how these factors interact to influence, through the mediating mechanism of the selfconcept, a consumer's brand attitude. Moreover, the propositions also consider how actual age potentially moderates these relationships. These propositions serve as a foundation for future consumer research that might investigate how the self-concept, through its full life cycle, impacts brand attitude.
The remainder of this article is structured as follows; first, it offers a background on the conceptualization of the self-concept and how brands are used as a means of self-expression, subsequently impacting brand perceptions such as brand attitude; second, it discusses the conceptual framework; third, the article presents the six research propositions. This is followed by directions for future research, and methodological and managerial implications, and the article's overall conclusions.

Background
The self-concept Since William James offered a rich account of the self-concept in his seminal text Principles of Psychology at the end of the nineteenth century, scholars have debated extensively about an adequate conceptualization of the self. A definition, widely used nowadays, was brought forward by Rosenberg (1979, p. 7), conceptualizing the self-concept as Bthe totality of an individual's thoughts and feelings having reference to himself as an object^. This definition encompasses the various views of previous scholars (e.g., Cooley 1964;James 1890;Mead 1934) as it describes how an individual processes internalized (private) aspects of the self-concept, as well as the importance placed on social interaction as part of the self-concept formation process.
From the 1970s onwards, research on the self-concept has registered a continued and growing interest by psychologists, as demonstrated by an increasing number of self-related publications (Swann and Seyle 2005). Important contributions considering the self-concept have been made in the domain of theory, such as the theory of self-perception (Bem 1972), the self-efficacy theory (Bandura 1977), and theories of attitude and value formation (Rokeach 1973). There has also been an evolution in terms of the conceptualization of the self-concept in the last decades. Rather than a static and mono-dimensional entity, there is a general consensus among self-scholars that the self-concept is not static but, rather, a dynamic multi-dimensional entity composed of private and public selves that include actual and desired (ideal) selves that have the potential to be modified over time (Markus and Wurf 1987;Reed II 2002;Swann et al. 2007). Epstein (1973, p. 4) highlights that the self-concept is a dynamic entity that changes with experience and, in particular, develops out of experiences rooted in social interaction with others. For instance, while infants tend to lack the ability to differentiate themselves from their environment, as they age and gain experience their self-concept becomes increasingly differentiated (Shavelson et al. 1976). In a similar vein, Demo (1992, p. 305) states that Bthe self-concept […] is a function of interacting biological, developmental, and social processes across the life course, it is acquired through patterns of interaction with others and is modified as children and adults develop new cognitive and intellectual capabilities and confront new social demands and processes^; hence, this also suggests that various factors influence the self.
There are two key conclusions that can be drawn from the conceptualizations of the self-concept outlined by previous scholars. First, due to the dynamic nature of the self, researchers need to consider an age perspective, i.e., how actual age influences the development of an individual's self-concept and resulting attitude and behavior. However, as shown in Tables 1 and 2 (see Appendix), prior research largely just acknowledges the dynamic nature of the self-concept in their discussion of the self-concept (e.g. , Campbell 1990;Marsh and Craven 2006), tests only one phase of the self-conceptlifecycle, such as adolescence or young adulthood (e.g., Briñol et al. 2006;, or outlines that the role of actual age needs to be considered in future research (Marsh et al. 2005). While these studies offer a foundation for future self-concept research, they do not provide theoretically grounded and testable propositions that account for all phases of the self-concept life cycle and its subsequent impact on attitude and behavior.
Second, drawing further from Demo's (1992) view, different lenses need to be applied in order to study the self-concept, as the self is influenced by various factors that are generally studied in disciplines such as cognitive psychology, developmental psychology, social psychology or sociology. The literature from various research domains supports this interdisciplinary notion, while documenting that the self-concept mediates the effect of various factors on individuals' attitude and behavior. Specifically, as illustrated in Tables 1 and 2 (see Appendix), evidence suggests that factors such as a leader's behavior (Marsh and Hocevar 1985), academic achievement Trautwein et al. 2006), evaluations of significant others (O'Mara et al. 2006), global culture (Arnett 2002;Erez and Gati 2004), life events (Cantor et al. 1987;Park 2010), as well as cognitive and desired age (Barak 2009;Loroz 2004;Stephens 1991) influence the self-concept, which in turn influences an individual's attitude and behavior. Furthermore, the self-concept has also been a topic of extensive debate in the consumer research domain, as outlined in the next section.

The self-concept and consumption
The self-concept is of particular interest to consumer researchers because consumers use the symbolic properties of brands as a means of defining and expressing their selfconcept (Ahuvia 2005;Belk 1988;Harmon-Kizer et al. 2013;Levy 1959). The image of a brand developed by marketers is understood and expressed by individual consumers and by society at large (Richins 1994). Therefore, brands offer consumers an outlet to project socially attributed meanings of their self. The knowledge of how brands are used as a means of self-expression has led to the theoretical development of self-congruity theory (Sirgy 1982), which posits that congruity between a brand's image and a consumer's self-concept produces positive consumer responses. A vast body of empirical research supports self-congruity theory, showing that the self-congruity effect leads to positive brand perceptions (e.g., brand attitudes, purchase intentions; Aaker 1997; Kressmann et al. 2006;Sirgy 1982;. Moreover, research in the consumer research domain continues to evolve alongside related research streams such as self-brand connections (Escalas and Bettman 2003). Specifically, when consumers form connections between their self-concept and a brand's image, this leads to positive brand evaluations and attitude strength (Chaplin and John 2005;Moore and Homer 2008). Studies in this research domain also emphasize the mediating role of the self-concept. For instance, Paharia et al. (2011) show that the self positively mediates the underdog brand effect on purchase intentions. Further examples also suggest that the self mediates the effect of value congruence on brand commitment (Tuškej et al. 2013), as well as the interaction of in-group identification and reference group labels on product evaluations (White and Dahl 2007), and the effect of a holiday destination personality on intent to return and recommend (Usakli and Baloglu 2011).
Taking into account that various factors influence the selfconcept, consumer researchers have also emphasized the importance of interdisciplinary research that uses multiple theoretical lenses to study consumer phenomena based on the self (McConnell 2011;Pham 2013;Reed II 2002). In line with studies from the field of psychology, numerous marketing studies have also adopted an interdisciplinary approach that considers the influence of various factors on the self-concept (for details see Appendix Table 1). As previously mentioned, the psychology literature highlights various antecedents of the self-concept (e.g., academic achievement, leadership, global culture, cognitive function); however, it should be noted that the current article is rooted in the consumer research domain and aims to account for the dynamic nature of the self-concept life cycle. Therefore, this article focuses on a select few antecedents of the self-concept that (a) are expected to be influenced by actual age and (b) are likely to have an effect on consumer phenomena. Specifically, the marketing literature suggests that global culture (Zhang and Khare 2009), life events (Mathur et al. 2008), as well as cognitive and desired age (Van Auken et al. 2006) influence consumer phenomena through changes to the self-concept, while also being affected by an individual's actual age (Appendix Table 2).
Interestingly, similarly to the psychology domain, the aforementioned studies either simply acknowledge in their discussion that actual age may influence how the self-concept affects consumer phenomena such as brand perceptions, or their research design only focuses on one phase of the self-concept life cycle. However, none of these studies accounts for the full life cycle of the self-concept. To bridge this knowledge gap, the current article considers the role of actual age in order to offer a foundation to improve the understanding of how each of these factors potentially influence the self-concept and, perhaps more importantly for consumer researchers, the subsequent impact on a consumer's brand perceptions. Recent reviews show that the self-concept is a key construct that influences consumer brand perceptions (Aguirre-Rodriguez et al. 2012;Hosany and Martin 2012). Evidence suggests that the self-concept influences various brand-related outcomes, such as brand loyalty (Mazodier and Merunka 2012;Sirgy et al. 2008), brand love (Batra et al. 2012;Carroll and Ahuvia 2006) or emotional brand attachment (Malär et al. 2011) to name a few.
It should be noted that the influence of the self-concept on brand-related outcomes is not limited to positive effects; for instance, Campbell et al.'s (1996) work on self-concept clarity highlights that individuals entertain confident and positive selfviews if they have a temporally stable and consistent perception about their self. If their self-view is shaken it can have a negative effect on individuals' psyche (Gao et al. 2009). Such a negative effect may be the consequence of identity inconsistencies and be reflected in brand choice (Kirmani 2009). However, while such negative effects are theoretically worthy of further investigation, this article focuses on the potentially positive effect of the self-concept on brand related outcomes. Ultimately, marketers are interested in how to create perceptions that consuming a specific self-matching brand will evoke a positive self-view that subsequently leads to a purchase.
In particular, brand attitude has received extensive attention in the marketing literature (e.g., Liu et al. 2012;Sirgy et al. 1991;. The emphasis of many studies on brand attitude as the key outcome variable influenced by the self-concept is not surprising. The seminal work by Fishbein and Ajzen (1975) set a foundation for consumer research, as attitudes influence behavior through behavioral intentions. This theoretical notion is further validated by empirical research showing that brand attitude affects brand consideration, purchase intention, purchase behavior and brand choice (Fazio and Petty 2007;Petty et al. 1995;Priester et al. 2004). Bearing in mind that data on actual behavior is generally difficult to obtain, constructs such as brand attitude serve an important role as potential predictors of behavior.
In summary, the literature suggests that various factors influence the self-concept, which subsequently impacts brand attitude. Moreover, due to the dynamic nature of the self-concept, its influence on brand attitude is potentially determined by changes in a consumers' self-concept over time. On the basis of these conclusions, the next section presents a conceptual framework that shows the influence of three antecedents of the self-concept and how actual age potentially moderates their impact on the self-concept and, subsequently, on brand attitude. Figure 1 shows the proposed conceptual framework. The conceptual framework is grounded in two central arguments. First, the self-concept is both cause (i.e., three antecedents) and effect (i.e., brand attitude). Second, due to the dynamic nature of the self-concept, actual age potentially moderates how the three antecedents influence the self-concept and, subsequently, brand attitude. These arguments are grounded in extant theoretical literature, as well as empirical findings on the self-concept discussed in the previous section (see Appendix Tables 1 and 2 for details). With regard to structure, the conceptual framework integrates the following components: (a) the first component includes the three antecedents of the self-concept, namely global culture, life events, as well as cognitive and desired age, which are described below in more detail; (b) the second component is the self-concept, which mediates the effect of the three antecedents on brand attitude; (c) the third component is actual age as a moderator of how the three factors influence the self-concept; and (d) the fourth component is the outcome variable, brand attitude. It should be noted that the propositions focus mainly on the selfconcept and brand attitude as broad constructs. First, as outlined in the self-concept literature, the self-concept is multidimensional and can represent facets such as a global self or a desired self (Arnett 2002;Markus and Wurf 1987). Similarly, brand attitude can, depending on a studies' context, refer to a variety of product and brand types. These can be, for instance, global, more utilitarian or hedonic (Özsomer and Altaras 2008;Voss et al. 2003). Therefore, a few distinctions with regard to the specific self-concept facets, as well as brand types and product categories, are mentioned wherever applicable in the discussion of the propositions (e.g., global brands).

Three antecedents of the self-concept
First, global culture is a form of culture created by global networks (e.g., multinational corporations and media), which cross national and cultural borders through a common Blan-guage^that communicates their values globally (Kostova and Roth 2003). Second, life events, such as marriage, parenthood, accidents or widowhood, are events that force individuals to adjust to new situations and roles (Mehta and Belk 1991). Third, cognitive age is a person's self-perception of what age that person feels like (perceived age), while desired age reflects the age a person aspires to be (Barak et al. 2011). Fig. 1 Conceptual framework. Note: The literature suggests that there are additional potential antecedents of the self-concept such as social norms, cognitive function, and neural structures that will potentially influence the self-concept and subsequently brand perceptions. However, the discussion of this article will explicitly focus on the conceptual development of the three antecedents outlined above, as these currently offer strong conceptual foundations to develop the proposed relationships
The sections that follow present conceptual arguments that set the foundation of the main propositions (P1a, P2a, P2b, and P2c) which discuss how the three antecedents influence the self-concept and, subsequently, brand attitude. Although these antecedents are conceptually distinct and the process by which they impact the self-concept varies, they are not independent of one another. Rather, an interaction between some of the factors takes place; hence, the main propositions consider the interaction of two of the factors. Moreover, for some of the main propositionswhere theoretical evidence suggests an effect of actual agethe paper presents a second set of propositions (P1b and P2d) that focus on the moderating effect of actual age between the antecedents and the self-concept and, subsequently, how this change in the self affects brand attitude.

Global culture and the self-concept
Global culture influences an individual's self-concept. Leung et al. (2005) argue that global culture is likely to evoke changes in the self, as cultural values are represented in an individual's self-concept and these changes will affect attitude and behavior. Due to the dominance of Western media and brands, global culture often includes elements of Western values which are notably individualistic (Stevenson and Zusho 2002;Zhou et al. 2010). In other words, a global culture can be embedded in the norms under which individuals operate in their environment. Due to these pressures, individuals are induced to behave in ways that allow them to fit into their social environment (e.g., Banerjee and Dittmar 2008;Elliott and Leonard 2004). Research shows that adopting a global culture is perceived as a social ideal (Skrbis et al. 2004). Therefore, individuals are likely to view positively behavior that allows them to embrace global culture as a means to redefining their self. From a marketing perspective, a consumer's self-view is relevant to a brand's positioning strategy as people tend to develop attitudes and behaviors that enable them to reinforce their self-view, while marketers can cater towards consumer needs with their brands (Westjohn et al. 2012). Specifically, marketing scholars offer evidence that consumers embracing global cultural values (e.g., openness towards foreign products, interest in languages) develop a global identity and react positively to brand positioning strategies that reflect values associated with a global culture (Cleveland and Laroche 2007;Zhang and Khare 2009).
Thus, global culture is a powerful driver that shapes an individual's self-concept and subsequently attitude. More formally: P1a: The (global) self-concept mediates the effect of global culture on attitude towards a global brand. Specifically, the greater the influence of global culture in shaping a (global) self-concept, the greater the positive attitudes towards global brands.

Moderating effect of actual age
Various arguments suggest that actual age moderates the effect of global culture on the self-concept and subsequent attitudes towards brands reflecting global values. The self-concept of adolescents and young adults is especially influenced by global culture. These individuals have enough maturity and autonomy to pursue information and experiences (e.g., through social media and the internet), while being less confined by an established way of life compared to older adults (Arnett 2002). For instance, social media sites offer an innovative peer culture among young people locally and globally that allows adolescents to express and integrate global values (e.g., openness towards foreign products, interest in languages) within their self (Livingstone 2008;Mangold and Faulds 2009).
Research also suggests that individuals exposed to global culture are more likely to have positive attitudes to global brands (Alden et al. 2006). In particular, adolescents are more prone than older adults to changing their behavior as a consequence to changes in their values and identity, specifically their self (Phinney et al. 2000). This phenomenon can be traced back to the impact of globalization on the self through a process of re-evaluation and construction (Chiu and Cheng 2007;Jensen and Arnett 2012). Consequently, adolescents and young adults are highly motivated to express their self through consumption practices that reflect this global culture. More formally: P1b: Actual age negatively moderates the effect of global culture on the (global) self-concept. Specifically, adolescents and young adults are more likely to develop a more (global) self-concept compared to older adults. Consequently, adolescents and young adults have a more positive attitude towards brands reflecting global values compared to adults in later life stages.
Life events, cognitive age and desired age Life events, such as marriage, parenthood, accidents or widowhood force individuals to adjust to new situations and roles. Some of these changes are less dramatic than others; nevertheless, as individuals adapt to their new roles and cope with the resulting effects on their lifestyles, they experience a need to redefine their self-concept (Mehta and Belk 1991). Consequently, by redefining the self-concept due to these new life roles, the behavior of these individuals also changes (Mathur et al. 2003). For example, Hemetsberger et al. (2009) suggest that drastic life events affect consumers' self and that these changes can influence their perception of different automotive brands, and even lead to brand switching. Further more, research also shows that consumers may attempt to change their consumption lifestyles and patronage orientations as a consequence of life events and the corresponding changes to their self (Lee et al. 2001).
Meanwhile, research indicates that life events can influence an individuals' perception of their cognitive age (perceived age) as well as their desired age. Cognitive and desired age are of particular interest to marketers, as they are better indicators of purchasing behavior than chronological age (e.g. Barak et al. 2011;Catterall and Maclaran 2001). For instance, new responsibilities such as parenthood are likely to foster an older cognitive age, which in turn will shape an individual's self (Johnson and Mollborn 2009). A further example is based on middle-aged individuals who sometimes experience a midlife crisis (Lachman 2004). In an attempt to project a desired younger self-image, which is significantly lower than their chronological age, middle-aged individuals are prone to purchasing goods such as sports cars or seeking plastic surgery (Guido et al. 2014;Ogle and Damhorst 2005;Zavestoski 2002). Furthermore, research shows that consumers are likely to perceive brands more positively that allow them to project an image that matches their actual and ideal self-view (Hollenbeck and Kaikati 2012;Malär et al. 2011;Sirgy 1982). In summary, life events influence consumers' selfconcept and subsequently their attitude towards specific brands. Moreover, life events influence consumer's cognitive and desired age which shapes their self-concept. These changes to their self subsequently affect their attitude and behavior. More formally 1 : P2a: The self-concept mediates the effect of life events on brand attitude. Specifically, the greater the influence of the life event on the self-concept, the greater (positive or negative) the effect on brand attitude.
P2b: Cognitive age mediates the effect of life events on the self-concept and subsequent effect on brand attitude.
Specifically, the greater the influence of a life event on cognitive age, the greater the effect of cognitive age on the self-concept. Consequently, the greater the change to the self-concept, the greater the effect (positive or negative) on individuals' attitude towards brands that match their perceived cognitive age.
P2c: Desired age mediates the effect of life events on the (ideal) self-concept and subsequent effect on brand attitude. Specifically, the greater the influence of a life event on desired age, the greater the effect of desired age on the (ideal) self-concept. Consequently, the greater the change to the (ideal) self-concept, the greater the effect (positive or negative) on individuals' attitude towards brands that match their perceived desired age.

Moderating effect of actual age
It is expected that the ideal self-concept mediates the effect of desired age on brand attitude and that this effect is influenced by actual age. As discussed in more detail below, this effect can be broken down into two processes. First, the effect of desired age on the ideal self-concept under the influence of actual age. Second, the effect of the ideal self-concept on brand attitude. Prior evidence shows that adolescents generally have desired ages that are older than their chronological age, which leads them to embrace self-enhancing activities that allow them to be perceived as more mature (Galambos and Tilton-Weaver 2000;Tilton-Weaver et al. 2001). For instance, in order to be perceived as adults, young females engage in the use of make-up, while some teenagers embrace habits such as smoking. Meanwhile, the marketing literature supports the idea that the consumption of products and brands is used as a potential means to self-enhance and/or restore a positive self-view (Grubb and Grathwohl 1967). Therefore, for individuals in their adolescence, it is expected that they are keen to consume brands that allow them to project a desired older selfimage that is in line with their ideal self. Conversely, during early adulthood individuals become again less self-conscious about how they are perceived. Specifically, the discrepancy between their ideal self-image and their actual age becomes less prevalent, which affects their consumption behavior (Gould and Barak 1988). Consequently, the influence of actual age on the effect of desired age on the (ideal) self-concept may be potentially weaker during later adolescence compared to early adolescence.
Interestingly, once individuals reach the later stages of their life (e.g., seniors above 65), their self-consciousness about their actual age becomes again more prominent. The desired age of individuals during late adulthood tends to be more than eight years younger than their chronological age (Guiot 2001). This notion is in line with the theory of continuity (Atchley 1993), which states that seniors intend to conserve the same aptitudes and physical, mental or social capacities as when they were younger. In an attempt to project a desired younger self-image compared to their chronological age, older individuals are prone to purchasing goods that allow them to project a younger ideal self (Guido et al. 2014;Ogle and Damhorst 2005;Zavestoski 2002). As seniors get older the discrepancy between the actual age and desired age is likely to grow. Thus, the influence of actual age on the effect of desired age on the (ideal) self-concept is expected to become stronger during the later senior years compared to earlier senior years.
Meanwhile, self-congruity theory (Sirgy 1982) posits that individuals are likely to perceive products and brands that match their ideal self-concept more positively as they seek to boost their self-esteem. Ample evidence supports the notion that brands that reflect individuals' ideal self are perceived more positively (Graeff 1996;Hollenbeck and Kaikati 2012). This notion should also translate to brands that allow individuals to reflect an ideal self-image that is in line with their desired age, as consumers may be motivated to use such brands to reduce the perceived discrepancy between their chronological and desired age. More formally: P2d: Actual age moderates the effect of desired age on the (ideal) self-concept. Subsequently, these changes to the (ideal) self-concept influence brand attitude. Specifically, from adolescence to young adulthood the (ideal) self reflects an older ideal self that leads to positive attitude towards brands matching that older ideal self. Conversely, from late adulthood the (ideal) self reflects a younger ideal self-image that leads to positive attitude toward brands matching a younger ideal self.

Directions for future research, and methodological and managerial implications Directions for future research
This article extends prior consumer research on the selfconcept by considering the dynamic nature of the selfconcept regarding its full life cycle, while also considering the influence of three factors emerging from various disciplines. Prior research has largely ignored the dynamic nature of the self-concept, with only a few studies highlighting the potential role of actual age in the self-concept life cycle (e.g., Chaplin and John 2005;Loroz 2004). The current article builds on prior work by offering theoretically grounded propositions that account for the dynamic age perspective of the self-concept and its potential effect on brand attitude. An additional contribution of this article is the adoption of an interdisciplinary perspective that accounts for the interactions of three factors that influence the self-concept and subsequently brand attitude, while also considering the role of actual age in these relationships. The conceptual framework presented in this article provides a platform for future studies by providing a Bbig picture^perspective of the dynamic nature of the selfconcept. In order to account for the potential interaction effects between the various factors, researchers should design interdisciplinary projects that investigate the influence of multiple factors on consumer phenomena. For instance, life events influence individuals' self-concept and the self-concept subsequently impacts brand attitude. Hence, there is a need for more empirical work examining the exact nature and effects of the relationships outlined in the propositions by using multiple methods and approaches. The section below proposes a few avenues for future research. First, as noted above, global culture potentially influences the self-concept and, in turn, brand attitude. Research indicates that global culture is responsible for the development of individuals with a global identity, and that a global identity is positively related to attitudes towards globally positioned brands (Zhang and Khare 2009). For instance, Tu et al. (2012) provide an 8-item scale to measure an individual's global identity. Meanwhile, well established measures to capture an individual's perception of a brands globalness are also available (e.g., Steenkamp et al. 2003). Future investigations could use field studies to examine how different levels and types of global culture influence individuals' global identity and, subsequently, their attitude towards global brands. Furthermore, taking into account that being global (i.e., having a global identity) is generally perceived as a social ideal among adolescents and young adults, studies should investigate the moderating effect of actual age between a global culture and individuals' self-concept. Such an investigation could show whether age influences how exposure to global culture (e.g., media) shapes individuals' self. Specifically, whether such exposure shapes their self into being more global and, consequently, if these changes to the self-concept lead to a more positive perception of brands that project global values.
Second, life events such as marriage or parenthood tend to force individuals to adapt to their new roles which redefines their self-concept (Mehta and Belk 1991). For instance, research using the notion of the possible selves (Markus and Nurius 1986) shows that becoming a first-time father changes an individuals' conception of their self as they adopt the new Bparent self^role (Strauss and Goldberg 1999). Future experimental studies could prime individuals towards different life stages such as single life or parenthood (Eibach et al. 2009) to investigate how such changes would affect their attitude towards particular products and brands. More specifically, studies could use such primes and apply Sirgy's et al.'s (1997) selfcongruity measure to evaluate potential changes to individuals' brand attitude towards cars or clothing products that may be congruent with the image of a single man versus a father. Alternatively, longitudinal designs that use qualitative approaches such as interviews would also be a viable alternative to explore the deeper psychological underpinnings of these self-changes and the subsequent impact on behavior and attitude.
Finally, to study the impact of life events on the selfconcept and, subsequently, brand attitude, researchers should also consider the influence of cognitive and desired age. For example, some middle-aged individuals experience a mid-life crisis which leads them to purchase products (e.g., a sports car) that allow them to project an image that is in line with their younger desired self-view. In line with the selfdiscrepancy theory (Higgins 1987), however, too great a discrepancy between the desired and actual self-image may lead to emotional conflict. Thus, it would be of interest to investigate empirically the impact of different age discrepancy levels between actual and desired age on brand attitude.

Methodological implications
Besides the proposed approaches outlined in the prior section to test the propositions outlined in this article, a variety of methods from different disciplines should be considered in order to improve the current understanding on how the three antecedents outlined in this article influence the self-concept across its full life cycle and, subsequently, impact brand attitude. First, it would be beneficial to move beyond the classroom to collect data and seek a wide range of consumer samples, as student samples offer only a limited perspective on the full self-concept life cycle and its subsequent impact on brand attitude. Second, research methods from various disciplines (e.g., psychology, sociology and neuroscience) should be combined. For instance, the integration of neuroscience into the consumer research domain has shown significant growth over the last years (Perrachione and Perrachione 2008;Plassmann et al. 2012). Neuroscienific methods provide direct information on how activity in selfrelevant brain regions (i.e., MPFC) affects decision-making related to brand perceptions (Ariely and Berns 2010;Ito 2010). This makes it possible to overcome the limitations of self-reporting in questionnaires or interviews, in which responses may not always be truthful (Pfeifer et al. 2009). Hence, consumer researchers might benefit from a combination of traditional self-reporting and neuroscience methods, which will provide richer data that will add depth and rigor to their findings. Third, numerous researchers have expressed the need for longitudinal studies in consumer research (Burroughs and Rindfleisch 2011;Raman and Leckenby 1998). Longitudinal studies are well suited to controlling for factors such as the influence of response biases, personality factors and demographic characteristics, as well as the resolution of issues of temporal sequence (Menard 2002). Therefore, although demanding in terms of resources, longitudinal studies covering various life-stages would present a broader perspective that may deepen our current knowledge of how the self-concept impacts brand attitude.

Managerial implications
The findings derived from the proposed conceptual framework will also have implications for marketing practitioners. Sprott et al. (2009) suggest that the level at which consumers engage and incorporate a brand as part of their self is integral in their attitude formation towards that brand. Therefore, marketers are keen to gain new insights on how they can strengthen the ties between their brands and the consumer. The section below discusses three potential issues that marketers should consider.
First, marketers are moving away from mass marketing to more targeted branding approaches (Malär et al. 2011). Therefore, it is increasingly important to understand selfrelevant consumer needs across various age segments. For instance, the aging of the world's population has created a burgeoning interest among marketers, researchers and policy makers in obtaining insights into the needs of older consumers, as these represent a potentially profitable consumer segment (Drolet et al. 2010;Moschis 2012). Moreover, the youth segment is also of growing importance due to the rise in disposable incomes and autonomous decision-making in brand purchases of adolescents around the globe (Gentina et al. 2014;Gil et al. 2012). Consequently, insights into what influences the brand attitudes of consumers in each life-stage will allow marketers to design targeted brand communications that elicit a positive response towards their brands. In particular, the internet offers a key avenue for marketers to engage with consumers through targeted branding.
Second, contrary to the conventional approach of segmenting consumer markets only at the country level, recent segmentation trends are moving towards segmenting consumer groups based on similar needs and behaviors, irrespective of country boundaries (Douglas and Craig 2011;Wedel and Kamakura 1999). Global culture is transcending borders, creating segments across countries that display similar needs and behaviors (Cleveland et al. 2011;Merz et al. 2008). Once marketers identify how global culture influences brand perceptions across the various life-stages of the consumer, they will be able to design their brand communications accordingly. For example, recent research indicates that cosmopolitanism is an indicator of product and brand preferences and has thus been suggested as a powerful segmentation variable (Riefler et al. 2012;Zeugner-Roth et al. 2015). Meanwhile, cosmopolitanism is linked to numerous demographic characteristics such as age, education, living in rural or urban areas and income levels. Considering that adolescents and young adults are likely to respond more favorably to brands associated with a cosmopolitan image than older consumers, it is possible to use age-based segmentation strategies to appeal to such consumer segments.
Lastly, life-event-based segmentation offers another viable alternative for marketers to reach consumers with specific needs. For instance, fatherhood or motherhood represents a significant change in a consumer's self-conception and the associated consumption patterns as an individual adapts to the new role (Mathur et al. 2003). Moreover, facing or overcoming a health-related hardship (e.g., cancer), which is more common in later life-stages, changes consumers' perception of their self (Zebrack 2000). Consequently, marketers should integrate elements into their brand communications that make consumers believe that consuming the brand will allow them to project their self in a way that reflects their new role in a positive manner. Timing and access to data are integral in this endeavor. Specifically, retailers are benefiting nowadays from advances in technology (Kumar et al. 2017); for instance, retailers can draw a vast array of insights from big data to make more precise and timely predictions about cyclical processes of consumer consumption (Grewal et al. 2017).

Conclusion
Consumers from various age groups should be considered to advance knowledge on how the self-concept impacts brand attitude. Moreover, it has been stated that the consumer research domain will benefit from Bcrossing disciplinary boundaries, by gaining breadth through conducting interdisciplinary research^ (Macinnis and Folkes 2010, p. 911). The conceptual framework presented in this article provides a foundation upon which to answer these calls. It offers a framework to deepen the understanding of how various factors interact to affect the self-concept in its complete life cycle and its subsequent impact on brand attitude. The article has presented six propositions that offer a foundation for future research. To test these propositions, it is recommended that researchers design interdisciplinary projects incorporating theoretical and methodological perspectives from various disciplines, specifically where the factors outlined are studied. Such a step offers excellent prospects of more comprehensive answers and new perspectives on how the self-concept affects brand perceptions; it also enables other questions to be investigated that are relevant to the consumer research domain. Besides enriching the theoretical understanding of this domain, findings derived from interdisciplinary projects can also benefit practitioners, as they may provide insights into how brands should be positioned when targeting consumers at different life-stages. Hence, it is imperative that as consumer needs evolve throughout their life-spans, consumer researchers and marketing practitioners adjust to the necessary changes as well. Table 1 Articles offering a static view of the self-concept

Authors and Year
Key insights and conclusions Sample Antecedents of the self-concept Markus and Wurf (1987) The self-concept is a multidimensional dynamic structure that actively changes and is involved in all aspects of information processing.
No sample, Literature review N/A Shamir et al. (1993) Presents a self-concept based motivational theory that explains how charismatic leader's behavior causes profound transformational effects on followers. The theory argues that charismatic leadership strongly engages the followers' self-concepts in the interest of the mission posited by the leader.

No sample, Theory article
Leader's behavior Rosenkrantz et al. (1968) Investigates the extent to which sex-role stereotypes, including their associated social values, influence the self-concepts of men and women. Results show that the self-concepts of men and women are similar to the respective gender stereotypes.
Young adults (undergraduate students) Sex-role stereotypes Greenwald and Farnham (2000) Offers evidence of the psychometric properties of self-esteem and gender self-concept measures using the implicit association test. The focus is methodological.
Young adults (undergraduate students) N/A Greenwald et al. (2002) Develops a unified theory that interrelates social psychology's most important cognitive constructs (stereotype and self-concept) with its most Young adults (undergraduate students)

Authors and Year Key insights and conclusions Sample
Antecedents of the self-concept important affective constructs (attitude and self-esteem). The main focus is on the Implicit Association Test. Sirgy (1982) Critically reviews self-concept research in consumer behavior including conceptual and measurement issues and offers guidelines for future research.
No sample, Literature review Self-consistency and self-esteem Grubb and Grathwohl (1967) Develops a partial theory of consumer behavior that links an individual's self-concept with the symbolic value of goods. The study presents the self-concept as a key determinant of consumer behavior. Goods serve as social symbols and are communication devices for the individual that allow him/her to further and enhance his self-concept.
No sample, Theory article Social experience Hong and Zinkhan (1995) Investigates if advertising appeals congruent with an individual's self-concept are superior to incongruent ads to enhance advertising effectiveness. Self-congruity has a positive effect on brands attitude and purchase intent, but not brand memory. Ideal self-congruity has a stronger effect on brand attitude than actual self-congruity.
Young adults (undergraduate students) N/A Funk and Buchman (1996) Investigates the association between the preference for violent games, frequency and location of play, and the self-concept. The self-concept is a key indicator of adolescent's core attitudes and coping abilities. Landon (1974) Investigates the influence of actual and ideal self-congruity on purchase intentions. Consumers differ with regard to which self-congruity type (actual vs. ideal) influences purchase intentions.

Adolescents N/A
Young adults (undergraduate students) N/A Zinkhan and Hong (1991) Investigates if advertising appeals congruent with an individual's self-concept are superior to incongruent ads. Self-congruity has a positive effect on brands attitude and purchase intent, but not brand memory. Ideal self-congruity has a stronger effect on brand attitude than actual self-congruity.
Young adults (undergraduate students) N/A Mazar et al. (2008) Outlines and offers empirical support for a theory of self-concept maintenance. The findings show that people behave dishonestly enough to profit but honestly enough to avoid spoiling a positive self-view.
Young adults (undergraduate students) Swann et al. (2007) Reviews the literature to outline strategies to make an adequate assessment of the predictive validity of the self-concept. The self-concept is an important predictor of socially important outcomes. The importance an individual places on a specific dimension of the self-concept influences the predictive validity.
No sample, Literature review N/A Marsh et al. (2005) Uses the reciprocal effects model to test self-concept as a cause and an effect of achievement in an academic context. The results show that self-concept can act as both, but that the effect of the self-concept as antecedent is stronger.

Adolescents
Self-concept is antecendent of academic behaviors O'Mara et al. (2006) Evaluates the impact of self-concept interventions for children using a blend of meta-analysis and multidimensional construct validation. Interventions that focus on specific self-concept dimensions rather than the global self-concept are more effective.
Meta-analysis of studies using children to adolescents.  Marsh and O'Mara (2008) Evaluates contradicting findings from two previous studies on the influence of academic self-concept on academic performance. Academic self-concept has a consistent reciprocal effect with achievement and educational attainment, while self-esteem had almost none.

Adolescents
Evaluations by significant others, Back et al. (2009) Develops a behavioral process model of personality that shows how explicit and implicit aspects of the self-concept of personality predict actual behavior. The direct measure of the BIG Five dimensions predicts behavior. The indirect measure of neurocism and extraversion do also predict behavior.
Undergraduate students Self influences behavior Trautwein et al. (2006) Develops a model of the effects of tracking on self-concept and interest that integrates the opposing predictions of Bcontrast^and Bassimilation^effects. Moreover, teacher-assigned grades are specified as a major mediating variable. The results show that students' math self-concept and math interest differ based on the achievement of their reference group, their teacher-assigned grades, and their own achievement.
Adolescents academic self-concept is positively influenced by individual achievement, Briñol et al. (2006) Investigates if individuals with discrepancies between their explicit and implicit self-conceptions might demonstrate similar motivation to process discrepancy-related information, even if they are not aware of the discrepancy. Individuals might be motivated to examine relevant information to minimize potential implicit doubt due to inconsistency between explicit and implicit self-conceptions.
Young adults (undergraduate students) Self influences judgement and action. Chiu and Cheng (2007) Discusses the role of globalizations cultural impacts from a social psychology perspective. Specifically, that a simultaneous activation of cultural representations does not directly determine an individual's cultural identity. Rather, this process enhances the distinctions between an individuals' identities.
No sample, Literature review Global and local culture Strauss and Goldberg (1999) Examines differences in men's self during pre-and post-childbirth. Results indicate that child birth influences men's self-view and has an effect on their psychological well-being, and their involvement with their infant.
Adult men aged 20-47 Life events Mathur et al. (2003) Investigates the relationship between individuals' life, resultant stress and lifestyle changes and subsequent changes in brand preference. Results suggest that life events (e.g., marriage, divorce, death) impact brand preference changes as a means of adjusting to new life conditions and their effect on the self.
Adults aged 21 to 84 Life events Guiot (2001) Examines the antecedents that influence a youthful bias of senior women towards a younger cognitive age.
Adult women aged 50-83 Younger feeling influences cognitive age. Guido et al. (2014) Investigates if cognitive age is a malleable construct that differs according to its context of reference.
The results indicate that the physical environment, the social references, and the product categories (hedonic vs. utilitarian) influence cognitive age perception.
Adults aged 65+ Social reference and product categories affect cognitive age and resulting self  Marsh and Hocevar (1985) Applies Confirmatory Factor Analysis to test Shavelson et al. (1976) theoretical predictions about the structure of self-concept. The focus is methodological.
Children from 2nd to 5th grade Leader's behavior Highlights that the facets of self-concept become more distinct with actual age, but does not offer testable propositions. Epstein (1973) Synthesizes divergent viewpoints about the self-concept while assessing the exploratory value of the self-concept construct.
Establishes that the self-concept, as the nucleus of the personality, plays a key role in determining what concepts are acceptable for assimilation into overall personality.
No sample, Theory article N/A Highlights the dynamic nature of the self, with regard to personality changes, but does not specifically focus on actual age. Campbell (1990) Examines the association between evaluative and knowledge components of the self to test if the self-concepts of low self-esteem individuals are characterized by less clarity or certainty than those of high self-esteem individuals.
Young adults (undergraduate students) N/A Acknowledges conceptually the dynamic nature of the self over time, but does not consider actual age in the research design.
Reed (2002) Discusses the implications of social identity for consumer research considering the self-concept as a foundation. The article also addresses the various conceptualizations of the self-concept used in the psychology domain and discusses the changes of the self-concept over time.
No sample, Literature review Social identity related factors Highlights dynamic nature of the self in terms of actual age, but does not offer any specific suggestions or propositions on how these chances may impact consumer behavior.
Loroz (2004) Uses a phenomenological investigation to show that the psychological benefits of gambling and other forms of experiential consumption can reinforce and enhance seniors' self-concepts. Argues that life transitions have an impact on the self-concept.
Adults aged 55 and above

Life events and transitions
Highlights the dynamic nature of the self-concept influenced by life events in old age. Mehta (1999) Uses psychographic variables to understand how self-congruity influences purchase intent in advertising. Self-congruence is positively related to purchase intent. Psychographic differences between the consumers (e.g. adventurous, elegant, and sensitive) influence how strongly the self-congruity effect impacts purchase intent.
Adults (  achievement. Moreover, further support on the multidimensional nature of the self-concept is provided. (e.g., social self-concept, emotional self-concept, physical self-concept).  Investigates the relations between multiple dimensions of self-concept, personality (Big Five), well-being, and academic outcomes. Different dimensions of the self-concept (e.g., appearance, same-sex, opposite-sex, parents, and intelligence self-concept) demonstrate differentiated pattern of relations with personality factors and academic outcomes.
Highlights that actual age is linked to academic self-concept, but does not focus the analysis specifically on actual age. Arnett (2002) Argues that many people around the globe merge local and global cultures into a bicultural identity.
Highlights that identity confusion may be especially prevalent among young individuals and that changes with regard to their self are likely as they grow up.
No sample, Literature review Global and local culture Discusses actual age differences with regard to the adaptation of global culture and the potential influence of age on the self-development process, but does not offer applications to consumer behavior.
Jensen and Arnett (2012) Discusses how theories of immigrant acculturation are included in the context of globalization to demonstrate that in particular adolescents and young adults are especially prone to be influenced with regard to their identity. Implications on gender issues and civic involvement are presented.
No sample, Literature review Global culture Discusses actual age differences with regard to the adaptation of global culture and the potential influence of age on the self-development process, but does not offer applications to consumer behavior. Martin and Kennedy (1993) Offers evidence suggesting that the tendency of female pre-adolescents and adolescents to engage in social comparison with models in ads increases with age. Moreover, suggests that this tendency is heightened for females with lower self-perceptions of physical attractiveness and/or self-esteem.

Pre-adolescents and adolescents
Social norms Suggests that actual age has an influence on how likely females are to be affected by social norms in their self-perception, but does not offer applications to consumer behavior. Rutland et al. (2005) Examines, among children, the effect of social norms and concern for self-presentation on intergroup attitudes. The findings show that as children age they are more likely to be internally rather than externally motivated to inhibit in-group bias in their decision-making.
Children aged 6-16 Social norms Suggests that actual age influences how children's self affects intergroup attitude, but does not offer applications to consumer behavior. Palkovitz et al. (2001) Discusses how fatherhood, and in particular fathering influences men's early adult development. Direct involvement in the fathering process has a profound impact on a person's self-perception.
Adult men aged 20-45 Life events Suggests that the actual age when a person becomes a father influences his self-development, but does not offer applications to consumer behavior.

Johnson and Mollborn
Investigates the subjective meanings of maturity in adolescence. The qualitative analysis shows that adolescents perceive various images of maturity influenced by factors such as privilege, physical development, power and status.
Adolescents grade 6 and 9 N/A Suggests that actual age influences which factors are associated with maturity, i.e., a higher subjective age. Chaplin and John (2005) Examines how children and adolescents incorporate brands into their self-concepts and are able to make self-brand connections.
Results show that the ability to make self-brand connections develops mainly from late childhood to early adolescence.
Children and adolescents aged 8 to 18 Cognitive function Discusses the role of actual age in children's ability to form self-brand connections. Demo (1992) Offers an account of how the self-concept develops over time. The paper suggests that the self-concept undergoes constant transformation from early childhood to late adulthood.
No sample, Literature review Cognitive function Discusses the dynamic nature of the self-concept and highlights the influence of actual age in the various life cycle stages, but lacks applications to consumer behavior.