📄 social_science

The Influence of Believability, Credibility and Trust on Social Shopping Intention in Vietnam: The Mediating Role of Subjective Norms

This study of 376 Vietnamese Generation Z consumers reveals that while trust directly drives social shopping intention, credibility influences it indirectly through subjective norms, and believability exerts both direct and indirect effects, highlighting the distinct roles of psychological trust and social consensus in social commerce.

Original authors: Thi-Trang Tran, Ly-Minh-Tri Tran, Khoa Nguyen, Hoang-Nhut Nguyen, Thi-Phuoc-Loc Nguyen, Thai-Anh-Tai Chau

Published 2026-07-31

📖 6 min read🧠 Deep dive

CC BY 4.0

Original authors: Thi-Trang Tran, Ly-Minh-Tri Tran, Khoa Nguyen, Hoang-Nhut Nguyen, Thi-Phuoc-Loc Nguyen, Thai-Anh-Tai Chau

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Imagine the internet as a giant, bustling digital town square. In this square, people don't just walk by; they shout recommendations, share reviews, and point at things they like. This is the world of social commerce, where shopping isn't a lonely act in a store but a group activity happening on apps like TikTok and Facebook. To understand why we decide to buy things here, scientists look at three main "mental gears" that turn in our heads. First, there's Believability: the gut feeling that a message sounds real and makes sense, like hearing a friend say, "This pizza place is amazing!" Second, there's Credibility: the more careful check of whether the source is an expert or trustworthy, like asking, "Is this person who says they know pizza actually a chef?" Third, there's Trust: the deep confidence that the whole system won't cheat you, like knowing the credit card machine is safe.

But there's a fourth, invisible force at play: Subjective Norms. Think of this as the "vibe" of the crowd. It's not just about what you think; it's about what you think everyone else thinks you should do. If you feel like your friends, influencers, and the whole internet are nodding in agreement, you feel a social pressure to join in. Researchers have long wondered how these gears—believability, credibility, trust, and the crowd's vibe—work together to make a person actually click "buy." This question matters because as more of us, especially young people, shop online, understanding the psychology behind the "add to cart" button helps us understand how we make decisions in a world flooded with information.

The Social Shopping Detective Story

In this study, a team of researchers from Vietnam decided to play detective with 376 members of Generation Z (people born between 1997 and 2005). They wanted to solve a mystery: When a young person in Vietnam sees a product on social media, what actually pushes them to buy it? Is it because the ad looks real? Because the reviewer seems smart? Because they trust the app? Or because they feel like "everyone else is doing it"?

The researchers built a map of how these ideas connect, using a mathematical tool called PLS-SEM (which is like a super-advanced calculator for checking relationships between ideas). They asked the young shoppers to rate their feelings on a scale from 1 to 5. Here is what they found, and it turns out the answer is a bit more complicated than just "trust the expert."

The "Crowd Vibe" is the Real Boss of Credibility

The most surprising discovery was about Credibility. You might think that if a review comes from a credible, expert source, you would buy the product immediately. But the study found that Credibility does not directly make you want to buy. Instead, it works like a megaphone for the crowd.

Imagine a famous chef (Credibility) says a new burger is great. The study suggests that this doesn't make you hungry directly. Instead, the chef's stamp of approval makes you think, "Wow, everyone must agree this is the best burger!" This feeling that "the crowd approves" is what actually makes you want to buy. The researchers found that credibility influences Subjective Norms (the crowd vibe) very strongly, and that is what drives the shopping intention. In short: Credibility is the spark that lights the fire of social pressure, but the fire itself is what warms you up to buy.

Believability: The "Double Agent"

Then there is Believability. This is the "gut check." The study found that Believability is a bit of a double agent. It works in two ways at once. First, it has a direct line to your shopping intention: if a message just feels real and plausible, you are more likely to buy. Second, it also works through the crowd. If a message feels believable, it makes you think, "Yeah, this must be what everyone is talking about," which strengthens the social pressure to buy. So, Believability is a "double agent" that influences you both personally and socially.

Trust: The Solo Driver

Finally, there is Trust. This is the feeling that the platform or the seller won't scam you. The study found that Trust is a "solo driver." It has a strong, direct line to your shopping intention. If you trust the system, you buy. But here is the twist: Trust does not seem to care about the crowd. The study found that Trust does not significantly influence Subjective Norms. You don't trust a platform because your friends say you should; you trust it because of your own experience with security and reliability. Trust and the "crowd vibe" operate on parallel tracks: one is personal safety, the other is social pressure.

What Was Ruled Out?

The researchers explicitly ruled out a few common assumptions.

Credibility is not a direct buyer: They found that Credibility does not directly influence shopping intention. If you just have a credible source but no social proof (no one else seems to care), the intention to buy doesn't go up.
Trust doesn't need the crowd: They found that Trust does not work through Subjective Norms. You don't need to feel social pressure to trust a platform; you trust it on your own.

How Sure Are They?

The researchers are quite confident in these specific relationships because they used a rigorous statistical method with 376 real responses. They found that the "crowd vibe" (Subjective Norms) is a crucial middleman for Credibility and Believability, but not for Trust. The model they built explains about 46.6% of why people intend to shop socially, which is a solid chunk of the puzzle, though it also means other factors (like price or personal taste) still play a role.

The Takeaway for the Real World

So, what does this mean for the future of shopping? The study suggests that if you want to sell something on social media, you can't just rely on having a "credible" expert say it's good. You have to make sure that credibility translates into a feeling that "everyone is doing it." You need to build social proof.

However, if you want to build Trust, you don't need to worry about the crowd as much. You just need to be secure, transparent, and reliable. And for Believability, you need to be both realistic (so it feels true) and aligned with what the community expects.

In the end, for Generation Z in Vietnam, shopping isn't just about the product; it's about the story the product tells about who you are and who your friends are. The "crowd" is the bridge that turns a credible fact into a shopping habit, while trust remains the quiet, personal foundation that lets you click the button in the first place.

Technical Summary: The Influence of Believability, Credibility, and Trust on Social Shopping Intention in Vietnam

Problem Statement and Research Gap
While social commerce has transformed retail by integrating e-commerce with social media, the psychological mechanisms driving social shopping intention (SSI) remain fragmented in existing literature. Prior studies often treat believability, credibility, and trust as isolated antecedents of purchase intention, failing to capture their joint influence within socially rich digital environments. Furthermore, the role of subjective norms as a mediating mechanism linking information cues (such as consumer-generated reviews and electronic word-of-mouth) to behavioral intention is underexplored, particularly among Generation Z consumers in emerging economies like Vietnam. This study addresses these gaps by integrating the Theory of Planned Behaviour (TPB) and the Information Acceptance Model (IAM) to examine how believability, credibility, and trust differentially influence SSI, both directly and indirectly through subjective norms.

Methodology
The study employs a quantitative, cross-sectional research design targeting Generation Z consumers in Ho Chi Minh City, Vietnam. Data was collected via an online questionnaire distributed between November and December 2025, yielding 376 valid responses after screening. The sample consisted predominantly of female students (79.79% female; 73.40% students) with high social media engagement, primarily on Facebook and TikTok.

The research model includes five constructs: Believability of Consumer-Generated Reviews (CGRs) and eWOM, Credibility of CGRs and eWOM, Trust in CGRs and eWOM, Subjective Norms, and Social Shopping Intention (SSI). Measurement scales were adapted from prior validated studies and measured on a five-point Likert scale. Data analysis was conducted using Partial Least Squares Structural Equation Modelling (PLS-SEM) via SmartPLS. The study assessed the measurement model for reliability (Cronbach's Alpha, Composite Reliability), convergent validity (Average Variance Extracted), and discriminant validity (Fornell-Larcker criterion) before testing the structural model and specific indirect effects through bootstrapping (5,000 resamples).

Key Results
The structural model analysis revealed distinct pathways for the three antecedents:

Credibility: Credibility of CGRs and eWOM has a strong, significant positive influence on Subjective Norms ( $\beta = 0.622, p < 0.001$ ). However, the direct path from Credibility to SSI was not statistically significant ( $\beta = -0.082, p = 0.171$ ). The indirect effect of Credibility on SSI via Subjective Norms is significant ( $\beta = 0.168, p < 0.001$ ), indicating a full mediation effect.
Believability: Believability exerts a dual influence. It has a significant direct effect on SSI ( $\beta = 0.331, p < 0.001$ ) and a significant positive effect on Subjective Norms ( $\beta = 0.166, p = 0.002$ ). Consequently, the indirect effect via Subjective Norms is also significant ( $\beta = 0.045, p = 0.009$ ), supporting partial mediation.
Trust: Trust in CGRs and eWOM acts as a strong direct antecedent of SSI ( $\beta = 0.319, p < 0.001$ ). However, the path from Trust to Subjective Norms is not significant ( $\beta = 0.033, p = 0.457$ ), and the indirect effect is non-significant ( $p = 0.479$ ). This suggests Trust operates independently of social pressure.
Subjective Norms: Subjective Norms significantly influence SSI ( $\beta = 0.270, p < 0.001$ ).
Model Fit: The model explains 46.6% of the variance in SSI ( $R^2$ ), which is considered substantial for behavioral research.

Key Contributions and Significance
The paper claims to advance social commerce theory and practice in the following ways:

Theoretical Integration: By combining TPB and IAM, the study provides a unified framework that clarifies how information perceptions translate into behavioral intentions. It challenges the assumption that credibility and trust are interchangeable predictors.
Differentiation of Constructs: The findings delineate distinct roles for the three constructs:
- Credibility functions as a normative mechanism, influencing intention solely through collective validation (Subjective Norms) rather than individual persuasion.
- Trust operates as an individual-level, risk-reduction mechanism that drives intention directly, independent of social pressure.
- Believability serves as a bridge, influencing intention both through immediate evaluative judgment and by reinforcing collective acceptance.
Contextual Relevance: The study extends social commerce literature to the Vietnam context, an emerging market with high social media penetration. It highlights that in collectivist, digitally connected environments like Vietnam, credibility-based information requires social legitimacy (subjective norms) to influence purchasing, whereas trust remains a direct driver.

Managerial Implications
The authors suggest that marketing executives should adopt differentiated strategies:

To leverage Credibility, firms should focus on cultivating community-wide legitimacy through authentic user-generated content, peer reviews, and influencer collaborations to strengthen normative pressure.
To build Trust, firms must invest in individual-level risk reduction mechanisms, such as secure payment systems, transparent policies, and reliable customer service, as this does not rely on social endorsement.
Believability requires marketing communications that are both persuasive and aligned with shared community expectations.

Limitations
The authors acknowledge limitations regarding the use of convenience sampling and a cross-sectional design, which constrain causal inference and generalizability. The focus on Generation Z in Ho Chi Minh City limits the geographical and demographic scope. Future research is suggested to employ probability sampling, longitudinal designs, and Qualitative Comparative Analysis (QCA) to further explore these dynamics.