Influencers vs. Legacy Media on Instagram: Effects on Perceived Credibility and Following Intention

Paper Title

Influencers vs. Legacy Media on Instagram: Effects on Perceived Credibility and Following Intention

Publication Info

• Topic area: Social media news credibility and user behavior
• Keywords: Instagram, news credibility, influencers, legacy media, political ideology, selective exposure, trust, social media platforms, user behavior, mixed-methods study

Background and Problem

• Problem / challenge: The rise of influencers as news sources on social media has blurred the lines between professional journalism and personality-driven commentary, but little is known about how users evaluate credibility and engage with news from influencers versus legacy media, especially when both appear in the same feed.
• Significance: Understanding these dynamics is critical for addressing issues like selective exposure, polarization, and trust in online news ecosystems.
• Motivation and related work: Prior research has shown that political ideology heavily influences perceived credibility and trust in news sources, but limited work has explored how these dynamics play out specifically on Instagram, where influencers and legacy media coexist. This study addresses gaps in understanding the interplay of source type, political alignment, and user behavior.

Solution

• Proposed approach: A mixed-methods experiment to assess how source type (influencer vs. legacy media) and political ideology influence perceived credibility and following intentions on Instagram.
• Novelty:
  1. Investigates credibility perceptions across both influencers and legacy media within the same platform context.
  2. Examines the moderating role of political ideology in shaping credibility judgments and behavioral intentions.
  3. Provides qualitative insights into users’ reasoning for following or not following news accounts.
  4. Uses a fully counterbalanced experimental design to control for topic-specific biases.
• Procedure and key techniques:
  • Participants (N=120, balanced by political ideology) viewed Instagram posts from four accounts (two influencers, two legacy media; one left-leaning and one right-leaning for each type).
  • Credibility was measured using a 5-item, 7-point Likert scale adapted from established frameworks.
  • Following intentions were assessed through binary yes/no questions and open-ended responses.
  • Quantitative analysis employed Cumulative Link Mixed Models (CLMM) to assess predictors of credibility, while qualitative analysis used thematic coding to explore reasons for following intentions.

Results

• Concrete findings:
  • Left-leaning sources were rated as more credible overall (β = 1.538, p < .001).
  • Right-leaning participants rated legacy media as more credible than influencers (β = 1.262, p < .001).
  • Left-leaning participants showed strong ideological congruence effects, rating left-leaning sources significantly higher than right-leaning sources.
  • Right-leaning participants exhibited less variation in credibility ratings across source ideologies but preferred legacy media over influencers.
• Advantage over baselines:
  • Demonstrates that ideological congruence is a stronger predictor of credibility than source type, with nuanced differences between left- and right-leaning participants.
  • Highlights the persistence of traditional credibility markers (e.g., institutional authority) even in social media contexts.
• Experiments / evaluation:
  • Four Instagram accounts (@so.informed, @nytimes, @dhjr, @foxnews) were paired with four news topics (ICE, DOGE, El Salvador deportations, EPA).
  • A fully counterbalanced design ensured equal representation of account-topic pairings.
  • Measures included perceived credibility (Likert scale) and following intentions (binary and open-ended responses).
• Limitations and future work:
  • Focused exclusively on Instagram; results may not generalize to other platforms.
  • U.S.-centric study; cross-cultural replication is needed.
  • Short-term exposure; future research should examine long-term credibility judgments and behavioral patterns.
  • Limited to political news; other domains may yield different patterns.

Summary

This study explores how U.S.-based Instagram users evaluate the credibility of influencers versus legacy media, with a focus on political ideology. Findings reveal that ideological congruence is the strongest predictor of perceived credibility, with right-leaning participants favoring legacy media and left-leaning participants showing strong alignment effects. Despite the rise of influencers, traditional credibility markers like institutional authority remain influential. These insights have implications for addressing polarization and trust in social media news ecosystems, suggesting that while political identity dominates, users also consider factors like journalistic quality and authenticity. Further research is needed to generalize findings across platforms, contexts, and timeframes.