Ghaith Al-Abdallah, Nadine Khair, Paiman Jatto
6 min
This study investigates the psychological mechanisms that drive millennial female consumers to purchase fashion products recommended by Instagram influencers. Specifically, the authors explore how a follower's social identity—their sense of belonging and self-categorization within a digital community—translates into purchase intention. The researchers propose that this relationship is mediated by the perceived credibility of the influencer, defined by their trustworthiness, expertise, and physical or social attractiveness.
To test this, the authors employed a quantitative, correlational research design. They surveyed 421 millennial females in Erbil, Kurdistan, using a self-administered questionnaire. The data were analyzed using structural equation modeling (SPSS AMOS) to validate the proposed theoretical framework, which integrates Social Identity Theory and the Source Credibility Model.
The research confirms that all three dimensions of social identity—cognitive (self-categorization), evaluative (self-esteem derived from group membership), and affective (emotional attachment)—significantly and positively influence purchase intention. Furthermore, the study establishes that source credibility acts as a vital mediator. When followers strongly identify with an influencer's community, they are more likely to perceive the influencer as credible, which in turn increases their willingness to purchase the fashion items being promoted. This suggests that influencer marketing is most effective when it successfully aligns with the follower's sense of self and group identity.
For fashion brands and influencers, these findings shift the focus from merely seeking high follower counts to cultivating deeper community identification. By understanding that purchase intention is rooted in the follower's identity, marketers can refine their strategies to foster stronger emotional and cognitive bonds with their audience. The study highlights that credibility is not just an inherent trait of the influencer but a perception shaped by the follower's social identity, suggesting that brands should prioritize influencers who resonate with the specific values and identity markers of their target demographic.
This study examines how followers’ social identity dimensions—cognitive, evaluative, and affective—affect their purchase intention for fashion products promoted by Instagram influencers. It also explores the mediating role of source credibility factors, including trustworthiness, expertise, and attractiveness, in strengthening this relationship. Targeting millennial females, a key fashion consumer group, the study applies social identity theory, source credibility theory, and influencer marketing literature to develop its conceptual framework. A quantitative, correlational approach was used, employing a self-administered questionnaire distributed via a convenience snowball sample of millennial females in Erbil, Kurdistan. Data from 421 respondents collected between were analyzed using SPSS AMOS version 24. Findings reveal that all social identity dimensions significantly influence purchase intention, and source credibility factors play a direct mediating role in this relationship. These insights offer practical implications for marketers and influencers, helping them understand the impact of followers’ social identity on purchasing behavior and refining influencer marketing strategies. This research expands influencer marketing literature by demonstrating the mediating effect of source credibility on the link between social identity and purchase intention. This research provides practical implications for enhancing millennial consumers’ purchase intentions by leveraging social identity mechanisms. The findings offer valuable insights for both social media influencers and brands seeking to employ influencer marketing strategies effectively in fashion promotion.
Alex: And they combined that with measures of the influencer's credibility?
Sam: Right—they measured perceived expertise, honesty, and physical appeal. To make sure the survey questions were actually capturing what they claimed to capture, they ran a quality-control check. Think of it like verifying that all the questions about "belonging" actually cluster together logically, the way you'd expect test scores in the same subject to move together. Once they confirmed the survey was reliable, they used a modeling method that works a bit like a map of a city with one-way streets. It lets you test not just whether two things are related, but the specific direction—does identity lead to trust, or does trust lead to identity?
Alex: And what did the model show?
Sam: It showed the flow goes one way: identity shapes how you perceive the influencer's credibility, and that credibility perception drives purchase intent. Social identity alone explained a meaningful portion of why someone intended to buy. But when they added source credibility as the bridge, the model's explanatory power increased noticeably. That gap is the evidence that credibility is doing real work in the process, not just tagging along.
Alex: Which part of social identity turned out to matter most?
Sam: The emotional attachment piece—what the researchers call affective social identity. When you feel a deep emotional bond with a community, you're more likely to perceive the influencer as trustworthy, and that perception is what carries you to the checkout. The categorization and status aspects matter, but the emotional connection is the strongest gear in the machine.
Alex: That's consistent with what you'd intuitively expect. We buy from people we feel genuinely connected to, not just people who are famous.
Sam: And that's what makes the finding useful. It's not just confirming a hunch—it's mapping the specific path. Belonging creates the emotional bond, the bond shapes how you perceive the influencer's honesty, and that filtered trust leads to the purchase. Each step is distinct, and each one matters.
Alex: I want to push on the limits here, though. This was one specific group—what can we actually generalize from it?
Sam: The researchers were clear about this. The study focused on female millennials in Erbil, Kurdistan. That's a deliberate and specific sample, and the authors acknowledge it openly. Different cultures, different age groups, and different platforms all have their own dynamics. You can't simply transplant these findings onto, say, Gen Z on TikTok and assume the same mechanisms operate in the same way.
Alex: So it's a starting point, not a universal rule.
Sam: That's the right framing. The value is in the framework—the belonging-to-trust-to-purchase chain—rather than in any specific numbers. Future research could test whether the same mechanism holds in other cultures, other product categories, or even in contexts where influencers are encouraging people to buy less rather than more.
Alex: That's an interesting thought—de-influencing. Could the same trust filter work in reverse?
Sam: That's exactly the kind of question the authors flag for future work. If credibility is the bridge between identity and behavior, then an influencer who's trusted by a community might be just as effective at changing habits as at driving purchases. The mechanism would be the same; only the direction of the message changes.
Alex: So to pull the whole thing together: we aren't passive consumers. We're social creatures who use our sense of belonging to decide who is worth listening to, and that trust is what ultimately leads us to act.
Sam: That's it precisely. Social identity is the foundation, credibility is the bridge, and purchase intent is the result. Without that bridge of trust, the feeling of belonging rarely translates into action. The study gives us a clearer, more grounded way to understand how influence actually works in the digital age.
Alex: Thanks for walking through the logic, Sam. What looks like a simple ad turns out to be a fairly layered psychological process.
Sam: It was a pleasure. And understanding that chain—belonging, trust, action—matters beyond marketing. It tells us something about how we decide who to listen to, and why. Thanks for listening to ResearchPod.