“Sharing Is Bonding”: How Influencer Self-Disclosure Fuels Word-of-Mouth via Consumer Identification

Abstract

The growing influence of social media personalities in shaping consumer behavior presents significant opportunities and challenges for marketers. This research integrates Social Identity Theory with the influencer marketing literature to investigate how influencer self-disclosure affects word-of-mouth intentions through consumer identification. Across four experiments (N = 1048), we demonstrate that high influencer self-disclosure consistently increases consumers’ word-of-mouth intentions compared to low self-disclosure. Consumer identification with the influencer mediates this relationship, providing a psychological mechanism through which personal narratives translate into advocacy behaviors. Furthermore, we identify two important boundary conditions: self-concept clarity moderates the relationship between self-disclosure and identification, with stronger effects for consumers experiencing identity uncertainty; and cultural collectivism orientation moderates the identification-to-WOM pathway, with collectivistic mindsets amplifying the translation of identification into advocacy. These findings contribute to both theory and practice by elucidating the psychological processes underlying influencer effectiveness and offer strategic guidance for optimizing influencer communication across diverse consumer segments and cultural contexts.

1. Introduction

In today’s digital landscape, word-of-mouth (WOM) has evolved from traditional face-to-face conversations to powerful electronic recommendations that significantly impact consumer behavior. This transformation has been particularly evident in influencer marketing, where consumers increasingly rely on influencers’ opinions and recommendations for purchase decisions. According to industry data, approximately 49% of consumers trust influencer recommendations when making purchasing decisions [1], highlighting the substantial role influencers play in shaping consumer word-of-mouth intentions. This trust is foundational to WOM effectiveness, as Nielsen’s 2012 report demonstrated that 92% of global consumers trust recommendations from friends and family [2], a dynamic that influencers strategically attempt to replicate through authentic, personal connections with their audiences.

The global influencer marketing industry, valued at USD 21.1 billion, continues to experience significant growth as brands recognize influencers’ unique ability to generate authentic word-of-mouth among consumers [3]. However, this growth has been accompanied by increased regulatory scrutiny aimed at ensuring transparency and authenticity in influencer communications, such as the Italian Communications Authority (AGCOM) regulations [3] and the fine imposed on Kim Kardashian by the U.S. Securities and Exchange Commission’s [4]. These regulatory developments underscore the critical importance of authenticity and transparency in influencer marketing—factors that directly impact consumers’ trust and subsequent WOM intentions.

Against this backdrop, the depth and nature of influencer self-disclosure has emerged as a pivotal factor in shaping audience perceptions and responses. Self-disclosure can be defined as the voluntary sharing of personal information, experiences, and opinions to make oneself known to others [5,6]. It is commonly evaluated along two dimensions: breadth (the range of topics shared) and depth (the intimacy of disclosed content) [7]. Low self-disclosure usually involves surface-level or demographic information (e.g., daily routines, occupation), while high self-disclosure encompasses diverse and intimate topics, such as personal struggles or emotional experiences. This conceptual clarity allows for a more precise understanding of how influencers strategically use disclosure to foster connections with their audiences.

Recent research by Leite et al. [8] discovered that the intimacy, valence, and topic of self-disclosure significantly affect perceptions of influencer credibility, which in turn impacts consumer behavior. Their findings revealed that while intimate self-disclosure can reduce perceived message appropriateness and influencer credibility, positive self-disclosure tends to enhance these perceptions. This nuanced relationship between self-disclosure and audience response merits deeper investigation, particularly given the significant impact that WOM intentions have on brand success in the digital ecosystem.

The relationship between influencer self-disclosure and consumer responses can be understood through the lens of Social Identity Theory [9], which explains how individuals define themselves in terms of group memberships and derive value from those identities. When influencers share personal information, they create opportunities for consumers to identify similarities and develop a sense of connection. This identification process is critical, as Bu et al. [10] demonstrated that homophily—the tendency of individuals to associate with similar others—positively influences customer value co-creation behavior and correlates with expected brand value and purchase intention. Building on this insight, when consumers identify with influencers through self-disclosure, they may incorporate aspects of the influencer’s identity into their own self-concept, potentially leading to increased WOM intentions.

The mediating role of consumer identification in this relationship warrants particular attention. Hsieh [11] found that followers’ cognitive and affective identification toward influencers significantly impacts their purchase intention and e-WOM intention. This identification process is enhanced when influencers maintain consistent information and image cues across social media platforms. Similarly, Shehzala et al. [12] discovered that individuals actively engage in comparisons with influencers’ virtual self-presentation and treat them as emblematic of an ideal self. The resulting self-discrepancy can lead to both positive and negative affect, with positive affect having a beneficial impact on e-WOM and purchase intent. These findings suggest that the relationship between influencer self-disclosure and WOM intention is not direct but rather mediated through the psychological mechanism of consumer identification. However, the effects of influencers’ self-disclosure are not always straightforward. High-intimacy disclosures can produce dual outcomes: when aligned with consumers’ self-concept, they reduce self-discrepancy, elicit positive emotions, and foster favorable behaviors such as WOM; when conflicting, they amplify self-discrepancy, cause discomfort, and reduce credibility [8,12]. The underlying factors, such as self-concept clarity, remain underexplored, leaving the directional effects of intimacy an unresolved theoretical puzzle.

Interestingly, the effectiveness of this identification process appears to vary based on several factors, including the level of self-disclosure. Li et al. [13] found that authenticity, as the core of audience perception toward influencers, mediates the effects of influencer expertise and self-disclosure on followers’ purchase intentions. Their research specifically highlighted disclosure intimacy and narrativity as key elements of self-disclosure that impact perceived authenticity. This aligns with findings from Chung et al. [14], who demonstrated that influencers can increase audience engagement by referencing their close social ties. Their analysis of 55,631 posts across 763 Instagram influencers revealed that consumers respond more positively to posts that reference close social ties, particularly when first-person pronouns are used to describe special moments with these ties.

The existing literature, however, presents inconsistent findings regarding the optimal level of self-disclosure for influencers. While some research suggests that intimate self-disclosure enhances perceived authenticity and fosters stronger consumer connections [15], other studies indicate that excessive personal disclosure might diminish influencer credibility [8]. Additionally, research by Wu et al. [16] found that influencers’ intimate self-disclosure positively affected sustainable food purchase intention by mediating social and epistemic values, demonstrating the complex pathways through which self-disclosure influences consumer behavior.

These inconsistencies in the literature point to a significant research gap regarding the specific mechanisms through which influencer self-disclosure impacts WOM intentions and the conditions under which this relationship is strengthened or weakened. Despite growing recognition of the importance of influencer authenticity, as highlighted by Chen et al. [17] and D’Arco et al. [18], limited research has examined how varying levels of personal disclosure affect consumer identification with influencers and subsequent WOM behaviors. Furthermore, the potential moderating roles of individual differences such as self-concept clarity and cultural orientation remain largely unexplored in this context [19].

To address these gaps, the present research aims to investigate the following research questions:

RQ1: Does influencer self-disclosure (high vs. low personal disclosure) influence consumers’ word-of-mouth intention, and, if so, to what extent is this effect mediated by consumer identification with the influencer?

RQ2: Under what conditions does the relationship between influencer self-disclosure, consumer identification, and WOM intention strengthen or weaken, particularly considering self-concept clarity and cultural collectivism orientation?

Building on these research questions, guided by Social Identity Theory [9], our conceptual framework proposes the following causal chain: influencer self-disclosure fosters perceived similarity and authenticity, which enhances consumer identification with the influencer; in turn, stronger identification motivates consumers to engage in word-of-mouth (WOM) advocacy (SIT → self-disclosure → consumer identification → WOM) [20,21]. We propose a conceptual model in which influencer self-disclosure affects WOM intention through the mediating mechanism of consumer identification with the influencer. This relationship is further moderated by individuals’ self-concept clarity and cultural collectivism orientation, which may alter the strength and direction of the proposed relationships.

This research contributes to the existing literature in several important ways. Theoretically, it extends Social Identity Theory by examining how identity processes operate in digital influencer contexts, particularly how varying levels of personal disclosure impact consumer identification and subsequent behaviors. It also contributes to the growing literature on influencer marketing by providing a more nuanced understanding of the psychological mechanisms underlying effective influencer communication strategies. By integrating the moderating roles of self-concept clarity and cultural collectivism orientation, this research also addresses calls for more culturally sensitive approaches to consumer behavior theory.

From a practical perspective, this research offers valuable insights for brands and influencers seeking to optimize their communication strategies. Understanding the optimal levels of self-disclosure for fostering consumer identification and WOM behaviors can help influencers develop more effective content strategies. Additionally, recognizing how individual differences in self-concept clarity and cultural orientation impact these relationships can enable more personalized and targeted approaches to influencer marketing, potentially increasing its effectiveness across diverse consumer segments.

2. Literature Review

2.1. Social Identity Theory

Social Identity Theory, originating from the seminal work of Tajfel and Turner in the 1970s, posits that individuals derive part of their self-concept from membership in social groups and categories [22]. The theory explains how people’s sense of who they are is based on their group membership and how they strive to maintain a positive social identity. In the context of consumer behavior, Social Identity Theory has been applied to understand how consumers identify with brands, influencers, and social groups, influencing their attitudes and behaviors [23]. The current research status of Social Identity Theory in consumer behavior studies demonstrates its relevance in explaining various phenomena, including brand loyalty, consumer–brand relationships, and social media engagement [24]. Researchers have explored how social identity processes affect consumer decision-making, particularly in digital and social media contexts, where identity expression and group affiliations are prominent [25]. Social Identity Theory guides the understanding of how other variables influence consumers’ WOM intentions by explaining the psychological mechanisms of group identification and self-categorization. For instance, perceived similarity with an influencer can enhance a consumer’s sense of shared identity, leading to increased trust and positive WOM intentions [26]. The theory elucidates how influencer self-disclosure impacts consumers’ WOM intentions by highlighting the role of identity-based trust and social attraction. When influencers engage in self-disclosure, they may activate shared social identities with their followers, fostering a sense of in-group membership [27]. This shared identity can lead to stronger identification with the influencer, increased perceived authenticity, and greater likelihood of engaging in positive WOM behaviors. Moreover, self-disclosure can enhance the perceived closeness and relatability of the influencer, strengthening the follower’s social identity within the influencer’s community [28]. As consumers increasingly see themselves as part of the influencer’s in-group, they are more likely to engage in behaviors that support and promote the influencer, including positive WOM. The theory also suggests that consumers may use WOM as a means of expressing and reinforcing their social identity, particularly when the influencer’s values and image align with their own self-concept [29].

2.2. Influencer Self-Disclosure

Influencer self-disclosure refers to the extent to which social media influencers share personal information, experiences, and opinions with their audience [8]. This concept encompasses the degree of intimacy, depth, and authenticity in the information that influencers choose to reveal about themselves [16]. High self-disclosure typically involves sharing intimate personal stories, emotions, and experiences, while low self-disclosure maintains professional distance and focuses primarily on product information or general content [13]. The level of self-disclosure is a strategic choice that influences how audiences perceive and respond to influencer content, particularly in terms of authenticity, credibility, and relational closeness [14]. This variable plays a crucial role in shaping the effectiveness of influencer marketing by affecting the perceived genuineness of influencer–audience relationships and subsequent consumer behavior. Building on this foundation, the following sections explore how influencer self-disclosure impacts downstream consumer responses and identifies gaps in current understanding.

The level of influencer self-disclosure significantly influences consumer perceptions and behaviors through multiple psychological mechanisms. First, appropriate self-disclosure enhances perceived authenticity, which serves as a mediating factor between influencer characteristics and consumer responses [13,30]. When influencers share personal stories and experiences, they are often perceived as more genuine and trustworthy, which positively affects consumer engagement with their content [15]. However, Leite et al. [8] found that the relationship between self-disclosure and perceived credibility is nuanced, as overly intimate disclosures can sometimes reduce message appropriateness and influencer credibility compared to non-intimate disclosures. The valence of the disclosure also matters, with positive self-disclosures generally enhancing credibility more than negative ones.

Second, self-disclosure impacts consumer identification with influencers. Chung et al. [14] demonstrated that when influencers reference close social ties in their content, audience engagement increases significantly. This effect occurs because such disclosures satisfy viewers’ interpersonal curiosity and enhance perceived similarity between the influencer and their audience. Similarly, Shehzala et al. [12] found that influencer self-disclosure can trigger self-discrepancies in followers, who compare themselves to the influencer as an ideal self. This comparison can lead to both positive and negative affect, with positive affect driving increased electronic word-of-mouth (WOM) and purchase intent.

Third, self-disclosure influences consumer behavior through perceived value creation. Wu et al. [16] revealed that influencers’ intimate self-disclosure positively affects sustainable food purchase intention by mediating social and epistemic values. Similarly, D’Arco et al. [18] found that when influencers disclose their activism on social issues, it can enhance perceived authenticity and increase consumers’ prosocial behaviors, particularly when there is congruity between the influencer and the cause they support. This suggests that self-disclosure not only affects commercial outcomes but also broader social behaviors.

The effectiveness of self-disclosure varies across contexts. Park et al. [31] found that micro-influencers (with fewer followers) are generally perceived as more authentic than mega-influencers, suggesting that audience size moderates the impact of self-disclosure on perceived authenticity. Additionally, Andonopoulos et al. [32] discovered that while authenticity typically enhances purchase intentions for products endorsed by influencers, inauthentic influencers can still inspire consumers and positively influence their intentions to purchase hedonic products. This indicates that product-type moderates the relationship between influencer authenticity and consumer behavior.

Despite growing research on influencer self-disclosure, several important gaps remain in the literature. First, there is limited understanding of how different types of self-disclosure (e.g., personal stories, opinions, emotions) differentially impact consumer identification and subsequent WOM intentions. Second, most studies have focused on direct effects on purchase intention rather than examining the role of consumer identification as a mediating mechanism between self-disclosure and WOM behaviors. Third, research has not sufficiently explored how cultural and contextual factors might moderate the relationship between influencer self-disclosure and consumer responses, particularly in cross-cultural settings. Addressing these gaps would provide a more comprehensive understanding of how influencer self-disclosure shapes consumer behavior in the increasingly global social media landscape.

2.3. Consumer Identification with Influencers

Consumer identification with an influencer refers to the psychological connection where consumers perceive a sense of sameness or belonging with a social media influencer, incorporating aspects of the influencer’s identity into their self-concept [33]. This identification process involves consumers recognizing shared values, attitudes, or characteristics with influencers, fostering a relationship that transcends mere observation [34]. The strength of this identification is influenced by how much personal information influencers reveal about themselves, setting the stage for examining how varying levels of self-disclosure affect this crucial mediating mechanism.

Guided by Social Identity Theory, we posit that influencer self-disclosure enhances perceived similarity and authenticity, thereby increasing consumer identification. In the present research, self-disclosure is operationalized as a binary variable (disclosure vs. no disclosure), and our focus is on comparing these two conditions. Thus, we do not examine potential threshold effects associated with varying degrees of disclosure intensity and our hypotheses concern the positive impact of disclosure (vs. low) on consumer identification. When influencers share personal information, experiences, or challenges, they create opportunities for followers to recognize points of commonality, enhancing perceived homophily [12]. High levels of self-disclosure reveal the influencer’s genuine personality, making them appear more authentic and relatable compared to more curated, professionally focused content [14]. These personal revelations help transform parasocial relationships into deeper identification, as consumers begin to see the influencer as someone similar to themselves rather than a distant celebrity figure.

Consumer identification with influencers substantially influences downstream consumer behaviors, particularly WOM intentions. When consumers strongly identify with an influencer, they perceive the influencer’s successes and failures as their own, motivating them to support the influencer through endorsements and recommendations [35]. Identification serves as a psychological mechanism that transforms passive content consumption into active brand advocacy, as consumers seek to maintain cognitive consistency between their self-concept and behaviors [36]. Research demonstrates that identification mediates the relationship between influencer credibility and followers’ behavioral intentions, with stronger identification leading to a greater willingness to engage with branded content [37]. Furthermore, when consumers identify with influencers, they experience lower persuasion resistance and higher trust, making them more receptive to product recommendations [38]. The depth of this identification particularly influences consumers’ willingness to engage in electronic word-of-mouth, as they view sharing the influencer’s content as an extension of their own identity expression [39]. Critically, identification also produces stronger emotional responses to influencer content, creating more enduring impacts on purchase intentions and brand loyalty than mere surface-level engagement [40].

3. Hypothesis Development

3.1. Influencer Self-Disclosure, Consumer Identification, and WOM Intention

Social Identity Theory posits that individuals define themselves partly through group memberships and derive value from these social identities [9]. Within this theoretical framework, influencer self-disclosure—the sharing of personal information, experiences, and values—functions as a critical mechanism for establishing connections with audiences. When influencers engage in high levels of personal self-disclosure, they reveal authentic aspects of themselves that can resonate with consumers’ own identities or aspirations [8,13]. This disclosure creates psychological proximity that facilitates word-of-mouth (WOM) intentions, as consumers feel more connected to the influencer and, by extension, to the products they endorse. Conversely, low self-disclosure limits the basis for such connections, creating psychological distance that may inhibit WOM behaviors [14,41]. Research by Steils et al. [42] demonstrates that authentic self-presentation by influencers significantly impacts audience engagement and subsequent behavioral intentions. Similarly, Cascio Rizzo et al. [15] found that influencers who share personal narratives generate stronger consumer responses than those who maintain professional distance. These findings suggest that the depth of personal information shared by influencers directly influences consumers’ willingness to spread the word about endorsed products. Collectively, these insights pave the way for examining the psychological mechanism through which influencer self-disclosure affects WOM intention [43].

Importantly, high levels of self-disclosure enhance perceived authenticity, which plays a key role in strengthening consumer identification [44]. Authenticity triggers audiences’ perception of similarity: when influencers share experiences such as setbacks, personal struggles, or growth that overlap with the audience’s own experiences, the audience experiences a sense of “we belong to the same group” and incorporates the influencer into their own self-concept [45]. Self-congruence theory further explains that the real-life details shared—such as daily habits, values, and life principles—act as symbolic signals, satisfying consumers’ need for self-congruence when they align with their actual or ideal self [46]. For instance, an influencer advocating sustainable living and sharing eco-friendly practices attracts consumers who pursue similar lifestyles, reinforcing identification. Beverland [47] emphasized that authenticity is not only about accurate information but also a vehicle for value resonance, which, through consistent self-disclosure, strengthens alignment with consumers’ self-concept and enhances identification. Other studies support this view: research on influencers and their followers found that higher perceived authenticity boosted consumer identification [17], and the impact of authenticity varies by content type, with some formats having a stronger effect on consumer identification [48,49]. This suggests that diverse and authentic content helps influencers build deeper connections with consumers, enhancing their identification [50].

Building on this premise, consumer identification with the influencer emerges as a crucial mediating mechanism between influencer self-disclosure and WOM intention. When influencers share personal struggles, values, and experiences (high self-disclosure), they create multiple points of similarity and aspirational qualities with which consumers can identify [12]. This identification process aligns with Social Identity Theory, as consumers incorporate aspects of the influencer’s identity into their own self-concept [9]. Li et al. [13] demonstrated that disclosure intimacy and narrativity significantly enhance followers’ perception of authenticity, which subsequently strengthens identification. Once consumers identify with an influencer, promoting products endorsed by that influencer becomes an extension of self-expression and identity affirmation [51]. This identification motivates consumers to engage in behaviors that reinforce their connection to the influencer, including sharing information about endorsed products [52,53]. The mediation pathway is further supported by Park et al. [31], who found that perceived authenticity—often a product of genuine self-disclosure—transfers to the endorsed brand through consumer identification with the influencer. Importantly, Andonopoulos et al. [32] demonstrated that this identification-based influence operates even when consumers recognize the commercial nature of the relationship, provided the influencer’s self-disclosure appears genuine. However, when influencers maintain low self-disclosure, the limited basis for identification restricts this mediating pathway, resulting in diminished WOM intentions. This evidence suggests that consumer identification serves as the critical psychological bridge connecting influencer self-disclosure to subsequent WOM behaviors.

In summary, the literature supports a theoretical model wherein influencer self-disclosure affects WOM intention through the mediating mechanism of consumer identification. When influencers share personal information, they create opportunities for consumers to identify with them, which subsequently motivates WOM behaviors as expressions of that shared identity. Based on Social Identity Theory and the empirical evidence reviewed, we formally propose two hypotheses:

H1: 

Higher levels of influencer self-disclosure lead to stronger consumer identification with the influencer.

H2: 

Consumer identification with the influencer mediates the relationship between influencer self-disclosure and word-of-mouth intention.

3.2. Moderating Role of Self-Concept Clarity

The role of self-concept clarity in moderating the relationship between influencer self-disclosure and consumer identification is grounded in social identity theory and the self-concept development literature. Influencer self-disclosure—the sharing of personal information, stories, and experiences—serves as a mechanism through which consumers form connections with influencers [8,13]. When influencers reveal personal aspects of their lives, they create opportunities for followers to identify similarities and develop parasocial relationships [14]. However, the effectiveness of self-disclosure in fostering consumer identification likely varies based on individual differences in self-concept clarity, which refers to the extent to which one’s self-beliefs are clearly defined, internally consistent, and stable over time [54]. Individuals with low self-concept clarity typically have less defined self-views and are more susceptible to external influences when constructing their identities [55]. This susceptibility makes them particularly responsive to influencers’ self-disclosure, as they seek external reference points to shape their self-concept [12]. In contrast, individuals with high self-concept clarity possess more stable self-views and are less likely to incorporate external information into their identity [56]. Consequently, while influencer self-disclosure generally enhances consumer identification by creating perceived intimacy and authenticity [15], this effect is likely amplified for consumers with low self-concept clarity who are actively seeking identity markers. Together, these insights suggest that self-concept clarity serves as a critical boundary condition for the relationship between influencer self-disclosure and consumer identification.

Building on this premise, we propose that the positive relationship between influencer self-disclosure and consumer identification is contingent upon followers’ self-concept clarity. Specifically, consumers with low self-concept clarity are more receptive to influencers’ personal revelations, as they use this information to supplement their own unclear self-definitions [57]. For these individuals, influencer self-disclosure provides valuable identity resources that can be incorporated into their malleable self-concepts, thereby strengthening identification with the influencer [58]. In contrast, consumers with high self-concept clarity have less psychological need to adopt external identities as their self-concepts are already well-defined and stable [59]. From a Social Identity Theory perspective, self-concept clarity shapes how readily individuals integrate an influencer’s identity into their own self-concept, thereby influencing the strength of the self-disclosure–consumer identification link. They are therefore less likely to be influenced by an influencer’s self-disclosure when forming identification judgments. This differential impact explains why self-concept clarity moderates the relationship between influencer self-disclosure and consumer identification. Formally, we hypothesize:

H3: 

Self-concept clarity moderates the relationship between influencer self-disclosure and consumer identification, with the relationship being stronger for consumers with low self-concept clarity.

3.3. Moderating Role of Cultural Collectivism Orientation

Cultural collectivism orientation plays a significant role in shaping how consumers respond to social influence and form connections with others. Research suggests that individuals with collectivistic cultural orientations place greater emphasis on group affiliations, social harmony, and shared experiences compared to those with individualistic orientations [60]. Prior research shows that consumers high in collectivism are more motivated to engage in behaviors that benefit their social group, including sharing information and advocating for valued group members [61,62]. This collectivistic predisposition shapes how consumers connect with social media influencers, especially when influencers engage in self-disclosure. In such contexts, identification with the influencer leads consumers to integrate aspects of the influencer’s identity into their own self-concept, thereby fostering a psychological bond that underpins subsequent behaviors [12]. However, the strength of this identification–behavior link is likely contingent upon cultural orientation. Collectivistic individuals, who define themselves more in terms of group memberships and relationships, tend to be more receptive to social influences and more motivated to maintain social connections once established [13]. They are also more likely to engage in behaviors that demonstrate loyalty and commitment to those they identify with, as these actions affirm their relational self-construal [63]. Consequently, when consumers with collectivistic orientations identify with an influencer, they may feel a stronger obligation to support the influencer through behaviors such as WOM promotion, as this aligns with their cultural values of relationship maintenance and group loyalty. Together, these insights suggest that cultural collectivism may strengthen the relationship between consumer identification and behavioral intentions.

Building on this premise, we propose that cultural collectivism orientation moderates the relationship between consumer identification with an influencer and WOM intention. For consumers with high collectivistic orientation, identification with an influencer creates a stronger sense of connection and belonging, which aligns with their cultural emphasis on group membership and relational bonds [12]. This cultural predisposition enhances their motivation to support and promote the influencer as an extension of their social identity [33]. In contrast, consumers with low collectivistic orientation may identify with an influencer but feel less compelled to engage in supportive behaviors like WOM, as their individualistic values place less emphasis on group affiliation and more on personal autonomy [64]. In line with Social Identity Theory, individuals from collectivist cultures tend to place greater value on group-based identities, which can strengthen the translation of consumer identification into WOM behaviors. This moderating effect explains why identification may translate more strongly into WOM behaviors for some consumers than others, based on their cultural orientation. Therefore, we hypothesize:

H4: 

Cultural collectivism orientation moderates the relationship between consumer identification and word-of-mouth intention, with the relationship being stronger for consumers with high collectivism orientation.

See detailed research framework in Figure 1.

4. Methodology

4.1. Overview of Study

Across four experiments, we unpack how influencer self-disclosure shapes electronic word-of-mouth (e-WOM) and its psychology. Study 1 (N = 200, MTurk) manipulated high versus low disclosure in an Instagram post and showed that intimate narratives significantly heighten consumers’ willingness to recommend the influencer. Study 2 (N = 240, Prolific) replicated the main effect and demonstrated, via PROCESS mediation, that the uplift in e-WOM is transmitted through stronger consumer identification. Study 3 (2 × 2; N = 408) added a writing prime of self-concept clarity and revealed that disclosure effects intensify when followers feel uncertain about themselves. Study 4 (N = 416) primed collectivism versus individualism and found that the identification–advocacy link is steeper for collectivist mindsets, delineating a cultural boundary condition (see all scales in Appendix A). Collectively, the evidence traces a disclosure → identification → e-WOM pathway moderated by personal and cultural self-views, offering nuanced guidance for influencer communication strategies across diverse online samples (see

Table 1. Summary of study designs. All experiments were conducted on the Instagram platform.

Study	Sample Size (N)	Design	Study Purpose	Key Findings
Study 1	200 (MTurk)	2 (high self-disclosure vs. low self-disclosure)	Testing whether high influencer self-disclosure increases consumers’ WOM intention compared to low self-disclosure.	High self-disclosure led to stronger WOM intentions (M = 5.43) compared to low self-disclosure (M = 4.67)
Study 2	240 (Prolific)	2 (high self-disclosure vs. low self-disclosure)	Examine how influencer self-disclosure affects WOM intention through consumer identification as a mediator.	Higher self-disclosure increased consumer identification and WOM intention. Consumer identification partially mediated the relationship between self-disclosure and WOM intention.
Study 3	408 (Prolific)	2 (self-concept clarity: high vs. low) × 2 (influencer self-disclosure: high vs. low)	Investigate how self-concept clarity moderates the impact of influencer self-disclosure on consumer identification and WOM intention.	Higher self-disclosure increased consumer identification and WOM intention. These effects were stronger when followers had lower self-concept clarity, suggesting that identity uncertainty strengthens the relationship.
Study 4	416 (Prolific)	2 (self-concept clarity: high vs. low) × 2 (individualism vs. collectivism)	Examine how cultural collectivism affects the relationship between consumer identification with influencers and WOM intention.	Cultural collectivism strengthened the identification–WOM link. Participants with a collectivist mindset showed a stronger effect of identification on WOM intention.

).

4.2. Study 1: Main Effect

4.2.1. Purpose

Study 1 aimed to test the hypothesis that high influencer self-disclosure, compared to low self-disclosure, increases consumers’ WOM intention. To examine this relationship, we conducted an online experiment manipulating the level of influencer self-disclosure (high vs. low) and measuring its impact on participants’ willingness to engage in WOM behavior.

4.2.2. Stimuli and Pretest

Following Pechmann et al. [65], we randomly assigned participants to view either a highly personal or a minimally personal social-media post from a fictitious influencer. In the high-disclosure condition, the influencer shared intimate details about their life, including personal anecdotes about family gatherings, emotional struggles, and career challenges, presented with warm colors and close-up visuals that evoked a sense of connection, accompanied by emojis that reflected vulnerability and sincerity. By contrast, the low-disclosure post simply featured a generic promotional message about a product, without any personal insights, presented in a neutral color palette and distant camera angles that lacked emotional engagement. After exposure, respondents indicated their willingness to share the influencer’s content. We used a single-item measure to assess participants’ perceived level of self-disclosure: “To what extent did the influencer share personal information?” (1 = not at all, 7 = very much). A separate pretest on Prolific (N = 180) confirmed that the high-disclosure post was perceived as substantially more personal (M = 5.82, SD = 1.03) than the low-disclosure version (M = 2.74, SD = 1.21), t(178) = 18.65, p < 0.001. This perceptual difference is important because it validates the intended manipulation of disclosure intensity, ensuring that participants clearly distinguished between the high and low self-disclosure conditions before proceeding to the main study.

4.2.3. Procedure

A total of 200 participants were recruited from MTurk (50.00% female, M_age = 33.89) for a nominal payment and they were randomly assigned to one of the two conditions. At the beginning of the study, participants were randomly assigned to one of two experimental conditions (high self-disclosure vs. low self-disclosure) in a between-subjects design. All participants first completed demographic questions capturing age, gender, education level, and social media usage frequency to establish baseline characteristics and enable post hoc analyses of potential moderating factors.

Following the demographic assessment, participants were presented with a standardized introduction describing the study as an investigation of “social media content evaluation” to mask the specific research focus and minimize demand characteristics. Participants were then exposed to a social media post from a fictitious influencer named “Alex” (gender-neutral to control for gender effects), who was described as a lifestyle content creator with approximately 100,000 followers.

In the high self-disclosure condition, participants viewed a social media post in which the influencer shared intimate personal details including family anecdotes, emotional struggles, and career challenges. The post featured warm color tones, close-up visuals designed to evoke connection, and emojis reflecting vulnerability and sincerity (as per [65]). In the low self-disclosure condition, participants viewed a post from the same influencer containing only generic promotional content about a product, presented with neutral colors, distant camera angles, and minimal emotional engagement cues (see details in Appendix B). To ensure sufficient processing of the stimulus material, participants were instructed to view the post for a minimum of 30 s before proceeding, ensuring sufficient minimum processing time for all participants [66]. After stimulus exposure, participants completed a brief distractor task involving unrelated word puzzles to minimize potential demand effects and create temporal separation between independent and dependent variable measurements [67].

Following the distractor task, participants completed the WOM Intention scale adapted from Van Vaerenbergh and Holmqvist [68], responding to three items: “How likely are you to speak positively about this influencer?”, “I would recommend this influencer to my friends”, and “If my friends were looking for an influencer to follow, I would tell them to check out this influencer” (1 = not at all to 7 = very much, α = 0.91). Responses to these three items were averaged to create a composite WOM intention score. Additionally, participants completed attention check items to verify engagement with the stimulus material.

All materials and procedures were approved by the institutional review board prior to data collection, and participants provided informed consent before beginning the study.

4.2.4. Result

WOM intentions. A one-way ANOVA examining the effect of influencer self-disclosure on WOM intention revealed a significant main effect, F(1, 198) = 24.63, p < 0.001, η² = 0.11. Participants exposed to high self-disclosure content reported significantly stronger intentions to engage in WOM behavior about the influencer (M = 5.43, SD = 1.08) compared to those exposed to low self-disclosure content (M = 4.67, SD = 1.21). This moderate effect size suggests that when influencers share more personal information and experiences, consumers are substantially more likely to discuss and recommend the influencer to others, supporting H1 that higher levels of influencer self-disclosure lead to stronger consumer identification with the influencer.

4.2.5. Discussion

Study 1 demonstrated that high influencer self-disclosure significantly boosts consumers’ word-of-mouth intentions, supporting H1 and aligning with theories of social penetration. By sharing personal narratives, influencers foster authenticity and emotional closeness, prompting followers to advocate on their behalf.

4.3. Study 2: Mediating Role of Consumer Identification

4.3.1. Purpose

Study 2 aimed to empirically test the causal relationship between influencer self-disclosure and consumers’ WOM intention while examining the mediating role of consumer identification with the influencer. Building upon prior research in social media marketing, this study specifically investigates how varying levels of personal disclosure by influencers (high vs. low) affect consumers’ willingness to engage in WOM behaviors. In this study, we employed an experimental design to test our two hypotheses, i.e., (1) that higher levels of influencer self-disclosure lead to stronger consumer identification with the influencer, and (2) that this identification mediates the relationship between self-disclosure and WOM intention.

4.3.2. Stimuli and Pretest

Following Pechmann et al. [65], we randomly assigned participants to view either a high or low self-disclosure Instagram post from a fictitious lifestyle influencer named “Alex_everyday.” In the high-disclosure condition, the influencer shared a photo of a morning coffee setup alongside intimate personal details: “Morning rituals that keep me going through my anxiety struggles. Been dealing with panic attacks since college, and finding these small moments of peace has been my lifeline. Taking time for myself wasn’t easy with two kids and work pressure, but it’s become non-negotiable for my mental health journey.” The caption included three personal emojis and warm, intimate lighting. In the low-disclosure condition, the identical coffee setup photo appeared with minimal personal content: “Morning rituals. Taking a moment before starting the day. Finding small moments of calm makes all the difference. Enjoying this coffee before tackling my to-do list.” This caption used neutral emojis and the same lighting (see details in Appendix C).

A pretest conducted with Prolific participants (N = 180, 55% female, M_age = 30.2) confirmed that the high-disclosure post was perceived as substantially more self-revealing (M = 5.64, SD = 1.12) than the low-disclosure version (M = 2.91, SD = 1.35), t(178) = 15.37, p < 0.001, validating our manipulation.

4.3.3. Procedure

Two hundred and forty participants (49.17% female, M_age = 37.26, SD = 12.89) were recruited between 12 and 14 April 2025 from the crowdsourcing platform Prolific to take part in an online study described as “social-media content evaluation.” A priori power analysis conducted in G*Power 3.1 [69] showed that 200 respondents would yield 80% power to detect a medium effect (d = 0.40) at α = 0.05, so the sample size was inflated to allow for exclusions based on attention checks. Using a between-subjects design, participants were randomly assigned to one of two conditions that manipulated influencer self-disclosure (high vs. low).

After providing informed consent, respondents completed a short pre-exposure questionnaire recording age, gender, education, and habitual social-media use, information later treated as potential covariates. They were then told they would evaluate Instagram content being considered for a marketing campaign and viewed a post from a fictitious lifestyle influencer named “Alex_everyday.” Both versions displayed the same photograph of a morning-coffee tableau; the high-disclosure caption revealed intimate personal details about coping with anxiety and work–family pressure, whereas the low-disclosure caption offered a neutral description of enjoying coffee before starting the day. Participants were required to view the post for at least 30 s to ensure adequate exposure, ensuring sufficient minimum processing time for all participants [66].

Immediately afterward, they completed a brief filler task rating the visual aesthetics of the post on three seven-point items (attractive, visually appealing, professional-looking) to disguise the study purpose. Perceived self-disclosure was assessed with three seven-point items adapted from Bazarova and Choi [70] that asked how much personal or private information the influencer shared. Consumer identification with the influencer was measured by three seven-point items adapted from Duman and Ozgen [71], such as “This influencer’s success feels like my own success,” while word-of-mouth intention was measured with three seven-point items adapted from Van Vaerenbergh and Holmqvist [68], such as “I would recommend this influencer to my friends.” A single instructed-response item (“please select ‘4’ for this question”) served as the attention check. Control measures included general trust in influencers, self-reported social-media use frequency, and prior exposure to similar content; all multi-item scales exceeded the 0.70 Cronbach’s α threshold.

4.3.4. Result

WOM intentions. A one-way ANOVA was conducted to examine the effect of influencer self-disclosure (high vs. low) on WOM Intention. The analysis revealed a significant main effect of influencer self-disclosure, F(1, 238) = 15.72, p < 0.001, η² = 0.062. Participants in the high self-disclosure condition reported significantly higher WOM intention (M = 5.84, SD = 1.23) compared to those in the low self-disclosure condition (M = 5.12, SD = 1.45). This result supports the hypothesis that higher levels of influencer self-disclosure lead to stronger WOM Intention among consumers.

Consumer Identification with the Influencer. A one-way ANOVA was performed to assess the impact of influencer self-disclosure on consumer identification with influencer. The analysis yielded a significant main effect of influencer self-disclosure, F(1, 238) = 22.36, p < 0.001, η² = 0.086. Participants exposed to high self-disclosure reported significantly higher levels of consumer identification with influencer (M = 4.92, SD = 1.08) compared to those exposed to low self-disclosure (M = 4.17, SD = 1.31). This finding supports H1, indicating that higher levels of influencer self-disclosure indeed lead to stronger consumer identification with the influencer.

Mediation analysis. A mediation analysis using Hayes’ PROCESS Model 4 (5000 bootstrap samples) was conducted to examine the mediating role of consumer identification with the influencer in the relationship between influencer self-disclosure and WOM intention. The analysis revealed a significant indirect effect of influencer self-disclosure on WOM intention through consumer identification with the influencer (β = 0.39, SE = 0.09, 95% CI [0.23, 0.57]). The direct effect of influencer self-disclosure on WOM intention remained significant (β = 0.33, SE = 0.14, p = 0.018), indicating partial mediation (see Figure 2). These results support the hypothesis that consumer identification with the influencer mediates the relationship between influencer self-disclosure and WOM intention.

4.3.5. Discussion

Study 2 confirmed that consumer identification mediates the effect of influencer self-disclosure on word-of-mouth intentions. The mediation analysis revealed that personal disclosures heighten followers’ sense of shared identity, which in turn drives advocacy. This insight clarifies the psychological mechanism underlying disclosure effects and highlights identification as a pivotal process variable in social media influence.

4.4. Study 3: Moderating Role of Self-Concept Clarity

4.4.1. Purpose

The purpose of Study 3 is to examine the moderating effect of self-concept clarity on the relationship between influencer self-disclosure and consumer identification with the influencer, as well as its subsequent impact on WOM intention. This study aims to test the hypothesis that the relationship between influencer self-disclosure and consumer identification is stronger for consumers with low self-concept clarity.

4.4.2. Stimuli and Pretest

Two elements were manipulated to create the four experimental cells. Momentary self-concept clarity was primed with a three-minute writing exercise adapted from Lodi-Smith and DeMarree [72]. In the high-clarity version, the task was titled “My Core Self” and asked participants to list five enduring personal qualities, explain why each mattered, and rate on a seven-point scale (1 = very uncertain, 7 = very certain) how confidently each quality described them. The low-clarity version, titled “My Changing Self,” required listing five occasions in which they had acted inconsistently or felt unsure who they were, followed by parallel explanations and certainty ratings. Both prompts explicitly demanded five statements and imposed a 180-word minimum to equate cognitive load.

Immediately afterward, every respondent saw an Instagram post from a lifestyle influencer named “Alex_everyday.” The picture—a van parked at sunrise in the mountains with the influencer holding a coffee mug—was identical in all conditions. Only the caption varied. The high-disclosure caption revealed intimate personal history (“Road-trip mornings like this saved me when my divorce hit three years ago… depression still creeps in… grateful that 110 k of you have been part of this healing journey), whereas the low-disclosure caption described the scene without personal detail (“Nothing beats waking up to crisp mountain air on a road trip… hope you all get outside this weekend). Both captions contained 52 ± 2 words and three emojis to keep stylistic features symmetric; readability (Flesch–Kincaid grade level = 6.8) and valence (VADER compound = 0.62) were equated through iterative editing (see details in Appendix D).

A separate sample of 160 US adults was recruited from Prolific on 8 April 2025 and randomly distributed across the four stimulus combinations (n = 40 per cell). Participants first completed the assigned writing task and then viewed the designated Instagram caption. Prime effectiveness was assessed with the 12-item Self-Concept Clarity Scale [73] (α = 0.91). Perceived influencer self-disclosure was measured with three seven-point items adapted from Bazarova and Choi [70] (α = 0.94). To ensure symmetry, the same filler aesthetic ratings used in the main study separated the two manipulation checks.

A 2 × 2 ANOVA on self-concept clarity confirmed a strong main effect of the prime: respondents in the high-clarity condition reported greater clarity (M = 5.46, SD = 0.77) than those in the low-clarity condition (M = 3.18, SD = 0.81), F(1, 156) = 431.82, p < 0.001, η_p² = 0.74. Neither the disclosure caption nor the interaction reached significance, Fs < 1, indicating that the influencer text did not influence momentary clarity. A parallel ANOVA on perceived self-disclosure produced a significant main effect of caption: the high-disclosure version (M = 6.07, SD = 0.67) was rated as revealing more personal information than the low-disclosure version (M = 2.94, SD = 0.83), F(1, 156) = 995.16, p < 0.001, η_p² = 0.86. The priming manipulation and the interaction were nonsignificant, Fs < 1, confirming that self-concept clarity did not contaminate disclosure perceptions.

4.4.3. Procedure

This study employed a 2 (self-concept clarity: high vs. low) × 2 (influencer self-disclosure: high vs. low) between-subjects design. Four hundred and eight U.S. adults were recruited from Prolific (51.72% female, M_age = 38.41, SD = 12.57) between 15 and 18 April 2025 in exchange for monetary compensation and were randomly assigned to the four experimental cells. After providing informed consent, participants completed the three-minute writing prime that either reinforced a coherent “core self” (high clarity) or highlighted a “changing self” (low clarity). They then viewed the Instagram post from “Alex_everyday”; picture content, caption length (52 ± 2 words), emoji count, readability, and valence were held constant across disclosure conditions to ensure stimulus symmetry. A 30 s progress bar prevented premature advancement.

Immediately afterward, respondents answered the three-item Consumer Identification with Influencer scale [71] (α = 0.92) and the three-item word-of-mouth intention scale [68] (α = 0.93), all on seven-point response formats. An instructed-response item embedded among the measures served as an attention check. Finally, demographic information (age, gender, education, and social-media usage) was collected, after which participants were debriefed about the fictitious influencer and the purpose of the research.

4.4.4. Result

WOM intention. A 2 × 2 ANOVA with influencer self-disclosure and self-concept clarity as between-subjects factors revealed a significant main effect of self-disclosure, F(1, 404) = 33.72, p < 0.001, η² = 0.077, qualified by a significant interaction with self-concept clarity, F(1, 404) = 10.77, p = 0.001, η² = 0.026. The main effect of clarity was not significant, F(1, 404) = 1.59, p = 0.208, η² = 0.004. Simple-effects analyses showed that when self-concept clarity was low, participants exposed to high-disclosure content reported stronger WOM intention (M = 5.60, SD = 0.89) than those exposed to low-disclosure content (M = 4.70, SD = 1.05), F(1, 404) = 22.91, p < 0.001. Under high clarity, the same contrast was only marginal (M_high-disc = 5.40 vs. M_low-disc = 5.15), F(1, 404) = 3.19, p = 0.076, consistent with the prediction that disclosure effects intensify when consumers feel uncertain about themselves (see Figure 3).

4.4.5. Discussion

Study 3 revealed that the impact of self-disclosure on consumer identification is contingent on self-concept clarity, with stronger effects for those temporarily experiencing low clarity. These results suggest that consumers uncertain about themselves are more receptive to influencers’ personal narratives as a source of identity reinforcement.

4.5. Study 4: Moderating Role of Cultural Collectivism Orientation

4.5.1. Purpose

Study 4 investigates whether consumers’ cultural collectivism orientation alters the strength of the link between consumer identification with an influencer and word-of-mouth (WOM) intention. Consistent with H4, we predict that identification will translate into stronger WOM advocacy when consumers have a high collectivist (versus low collectivist) mindset, because collectivists place greater value on relational harmony and group-affirming behavior.

4.5.2. Stimuli and Pretest

Collectivism orientation was momentarily primed with a three-minute writing exercise adapted from Trafimow, Triandis, and Goto [74]. In the collectivism condition, the task was entitled “About Us” and asked participants to write 180–200 words describing a recent situation in which “your group or family succeeded together,” explicitly using plural first-person pronouns (“we,” “us,” “our”) at least eight times; certainty about shared values was then rated on a seven-point scale (1 = very uncertain, 7 = very certain). The individualism (low-collectivism) condition was structurally identical—heading “About Me,” identical word count requirement, minimum of eight singular pronouns (“I,” “me,” “my”)—but focused on a personal success unconnected to others, thereby equating cognitive effort and linguistic structure.

Immediately afterwards all respondents viewed the same high-disclosure Instagram post from “Alex_everyday” that had proven effective at eliciting identification in Study 3. Because self-disclosure was held constant, any variation in WOM would stem from identification levels and the collectivism manipulation.

A separate sample of 160 U.S. adults recruited on 10 April 2025 (n = 40 per cell) first completed the writing prime and then viewed the designated caption. Prime effectiveness was verified with the 16-item Cultural Orientation Scale [60] (α = 0.93; collectivism subscale). A 2 × 2 ANOVA showed a robust main effect for the prime: participants in the collectivism condition scored higher on collectivism orientation (M = 5.41, SD = 0.72) than those in the individualism condition (M = 3.24, SD = 0.80), F(1, 156) = 632.27, p < 0.001, η_p² = 0.80. Neither the caption manipulation nor the interaction was significant, Fs < 1. Perceived self-disclosure again differed only by caption (M_high = 6.11 vs. M_low = 2.96), F(1, 156) = 1781.44, p < 0.001, η_p² = 0.85, confirming that the two manipulations worked independently.

4.5.3. Procedure

Four hundred and sixteen U.S. adults were recruited from Prolific between 12 and 15 April 2025 (52.4% female; M_age = 37.9, SD = 12.80) and randomly assigned to one of two cultural-orientation conditions in a single-factor between-subjects design. After providing electronic consent, participants spent three minutes on a writing task adapted from Trafimow, Triandis, and Goto [74] that primed either collectivism or individualism. Those in the collectivism condition wrote 180–200 words describing a recent group or family success and were instructed to use plural first-person pronouns (“we,” “us,” “our”) at least eight times, whereas those in the individualism condition wrote about a personal success unconnected to others, using singular pronouns (“I,” “me,” “my”) with the same frequency requirement; a 30 s progress bar prevented premature advancement and ensured compliance. Immediately afterward, every participant viewed the same high-self-disclosure Instagram post from the fictitious lifestyle influencer “Alex_everyday,” featuring a sunrise mountain–van photograph and a 52-word caption that had proven effective at eliciting identification in Study 3; picture content, caption length, emoji count, readability, and valence were held constant, and the post remained on screen for 30 s before the survey advanced. Participants then completed focal measures on seven-point scales in the following order: consumer identification with the influencer (three items, [71], α = 0.92), and word-of-mouth intention (three items, [68], α = 0.93). An instructed-response item embedded among these measures served as an attention check; 4.6% of cases that failed the check were excluded prior to analysis, leaving balanced cell sizes and preserved power. Finally, respondents reported demographic information (age, gender, highest education achieved, weekly social-media use) and were debriefed about the fictitious influencer and the purpose of the study. The full session lasted approximately ten minutes, after which participants received compensation.

4.5.4. Result

WOM intentions. To examine whether collectivism orientation moderated the identification–WOM link, WOM intention was regressed on mean-centered consumer identification, a collectivism dummy (1 = collectivism, 0 = individualism), and their interaction. Identification exerted a strong positive main effect (β = 0.52, t = 16.66, p < 0.001). The interaction term was significant (β = 0.26, t = 4.38, p < 0.001), ΔR² = 0.03. Simple-slope analyses showed that the effect of identification on WOM was steeper under collectivism (b = 0.72, SE = 0.06, t = 12.44, p < 0.001) than under individualism (b = 0.32, SE = 0.06, t = 5.28, p < 0.001). Johnson–Neyman probing indicated that identification predicted WOM at p < 0.05 for all identification values above 2.09 in the collectivism condition versus 3.83 in the individualism condition, illustrating the broader range of influence in the collectivism mindset. See Figure 4 for the moderating role of collectivism orientation on identification.

4.5.5. Discussion

Study 4 confirms that consumers’ cultural orientation shapes the power of identification to translate into advocacy. Although influencer self-disclosure remains a reliable antecedent of identification, the leap from “feeling connected” to actually recommending the influencer is amplified when consumers are operating from a collectivistic frame of mind. For collectivism-primed participants, a one-unit rise in identification produced more than double the increase in WOM intention observed under an individualistic prime. These findings extend the boundary conditions of the identification–WOM pathway, demonstrating that social norms emphasizing group harmony and shared success heighten the motivational consequences of feeling psychologically merged with an online personality.

5. General Discussion

This multi-method program of four preregistered online experiments demonstrates that influencer self-disclosure reliably elevates consumers’ word-of-mouth (WOM) intentions and elucidates the psychological and contextual contingencies that shape this effect.

Study 1 established the basic phenomenon: exposure to a highly self-revealing social-media post produced stronger WOM intention than exposure to a minimally revealing post, supporting H1 [65]. Study 2 replicated the main effect and demonstrated that consumer identification with the influencer mediates the disclosure–WOM link, consistent with social identity theorizing [70]. Study 3 manipulated momentary self-concept clarity and found that the disclosure-to-identification pathway is amplified when clarity is low, highlighting identity uncertainty as a personal boundary condition [73]. Study 4 primed collectivism versus individualism and showed that the impact of identification on WOM is markedly steeper under a collectivistic mindset, underscoring the role of cultural orientation in relational advocacy [60].

Taken together, the four studies (total N = 1048) converge on a coherent mechanism: personal narratives foster parasocial closeness, which crystallizes into a sense of shared identity that—when coupled with self- or group-based motives—catalyzes WOM advocacy. A meta-analytic aggregation of the independent effect sizes yielded an average η² of 0.09, indicating a moderate and practically meaningful influence that persisted across platforms, disclosure exemplars, and measurement occasions. This research illustrates that influencer self-disclosure drives consumer identification, which subsequently increases word-of-mouth (e-WOM) intentions. The relationship is moderated by both personal factors (such as self-concept clarity, which strengthens the effect for those with lower clarity) and cultural factors (such as collectivism, which enhances the influence in collectivist cultures). This study refines traditional WOM models by incorporating narrative intimacy and extends Social Identity Theory into dynamic, situational contexts.

5.1. Theoretical Contribution

First, this research enriches the understanding of how influencer self-disclosure shapes consumers’ word-of-mouth (WOM) intentions. Across four experiments, higher personal disclosure increased WOM advocacy toward the influencer. While previous studies often associated disclosure with credibility or purchase persuasion [31,75], the impact on social transmission remained mixed. Anchored in Social Identity Theory [9], we argue that disclosure transcends credibility by activating self–other overlap, thereby motivating supportive communication. Our findings extend identity-based persuasion models by demonstrating that disclosure intimacy, rather than just personal cues, serves as a psychologically diagnostic signal that drives advocacy. This contribution refines traditional WOM models and integrates personal narrative richness as a key antecedent, updating theories on electronic WOM drivers.

Second, the research clarifies the psychological mechanisms through which disclosure operates. Mediation tests showed that consumer identification significantly mediated the effect of disclosure on WOM, while self-concept clarity and cultural collectivism modulated the pathway’s strength. Building on identity-integration work [12] and self-concept clarity theory [54], we reveal that identification is the necessary conduit: disclosure increases perceived similarity and authenticity, which in turn translates into identification and WOM. This conduit is stronger when followers lack a coherent self-view or endorse collectivistic norms, consistent with motivational contingency logic [59,60]. These findings refine multi-step influence models by specifying identification as the operative mediator and demonstrating dual moderators that regulate both antecedent–mediator and mediator–outcome links.

Third, by incorporating momentary self-concept clarity and primed collectivism orientation, this study introduces a contextual lens that advances influencer research beyond static, source-centered explanations. Previous studies have largely treated audiences as homogeneous receivers, rarely considering how identity fluidity or cultural mindsets affect persuasive outcomes [24]. Drawing on self-discrepancy and cultural self-construal perspectives [56,60], we show that disclosure-induced identification has the greatest impact when consumers are identity-uncertain or communal in orientation. This empirical account reconceptualizes influencer effectiveness as an interaction between narrative intimacy and followers’ psychological readiness to appropriate external identities. Consequently, the findings extend Social Identity Theory into dynamic, micro-situational contexts and encourage scholars to model consumer traits and cultural frames as real-time moderators of parasocial persuasion.

5.2. Practical Contribution

Influencers, brand managers, and social-media platform curators can immediately leverage the demonstrated effect of self-disclosure on WOM intention. Because posts with rich personal details boosted WOM intentions by more than half a scale point, influencers should schedule regular “back-stage” stories that reveal manageable vulnerabilities, such as career setbacks, to humanize their content. Brand managers should include disclosure benchmarks in briefing documents, e.g., requiring at least three personal life stories per sponsored campaign, to enhance earned reach. Platform curators can algorithmically highlight content that exceeds a calibrated disclosure threshold to amplify authentic voices and increase session time.

Since consumer identification mediates much of the disclosure effect, practitioners should focus on intensifying perceived similarity. After high-disclosure posts, influencers can include quick poll stickers asking, “Ever felt this way?” to trigger self-comparison. Identification is strongest among followers with low self-concept clarity, so campaigns targeting fresh graduates, new parents, or expatriates should foreground personal narratives. In collectivist markets, brands should weave inclusive language, such as “we” and “our journey,” into captions and invite group challenges to transform identity overlap into advocacy. Scheduling periodic live Q&A sessions where followers exchange parallel experiences further cements the bond. These tactics operationalize our PROCESS findings, transforming invisible mediators and moderators into manageable levers for higher earned reach.

To further expand on practical implications, influencers and brands can benefit from understanding how platform algorithms interact with the timing and presentation of self-disclosure. Content that is highly personal or intimate might be favored by algorithms on platforms like Instagram, potentially increasing visibility and engagement. Furthermore, brands should consider tailoring self-disclosure strategies to fit different platform dynamics, using algorithmic insights to identify when and how to reveal personal stories for maximum effect. For instance, platforms with algorithm-driven recommendations can prioritize more authentic content, meaning influencers who are more open about personal struggles or achievements could see a higher level of engagement. This could also influence the strategic planning of campaigns, where brand managers might adjust their messaging based on algorithmic preferences for content authenticity and emotional resonance.

Effective messaging should follow a narrative arc of adversity, coping, and modest triumph. This narrative structure helps create empathy and enhances WOM intentions. Influencers should complement the narrative with visual cues, such as warm tones, close-up images, and emojis, to emphasize vulnerability. Impersonal, product-centric messages tend to fail in evoking identification. For example, a skincare brand could shift from a neutral statement like “Our serum reduces wrinkles” to a more relatable, personal confession: “ Photoshoots left me insecure about my skin until I started using this serum; seeing the lines fade made me feel like myself again.” Additionally, brands must tailor their messaging based on cultural contexts. In collectivist cultures (e.g., East Asia, Latin America), messages that emphasize shared experiences—family milestones or team successes—will resonate better. In individualist markets (e.g., North America), self-reliance stories focusing on personal growth and overcoming challenges should be emphasized. A/B testing different narrative types across regions can help brands optimize disclosure depth and framing to match local cultural values.

5.3. Limitation and Future Research

This research presents several limitations. First, all four studies relied on convenience online panels (MTurk, Prolific) drawn largely from the United States; the homogeneity of these samples and their high social-media literacy may restrict the cultural and demographic generalizability of the findings [76]. Future research should replicate these findings with non-Western samples to assess their generalizability across diverse cultural contexts. Second, the dependent measures captured self-reported word-of-mouth intentions rather than naturally occurring referrals; stated advocacy often overestimates behavioral follow-through, so future work could track actual sharing behavior in field settings or with social-network data [77]. Third, the experimental design featured a single fictitious influencer posting coffee-related content, which, while controlling for variables, limited ecological validity. In reality, influencers often have pre-existing parasocial relationships and reputation cues that could influence their content and its reception. Future research should explore a variety of influencer types and disclosure formats across different platforms to assess their boundary conditions [65,78]. Addressing these issues with cross-cultural field experiments, multi-influencer designs, and longitudinal observations would clarify the robustness of the disclosure–identification–WOM pathway and illuminate how algorithmic contexts shape persuasive reach [79].