Just five Instagram-style posts. That's all it takes for people scrolling through their feeds to start forming opinions that stick—often before they've bothered to check whether the information is actually true.
This finding, published in Information Systems Research by researchers including Ashish Kumar Jha of Trinity Business School and Venu Puthineedi of NEOMA Business School, upends a comforting assumption we've long held about how beliefs form online. Most discussions about fighting misinformation rest on the idea that people first evaluate accuracy, then decide what they believe. The research suggests the opposite is happening in real time, every day, on platforms where users are scrolling faster than they're thinking.
The researchers ran three controlled experiments using Instagram-style posts to mimic everyday scrolling behavior. What they discovered was stark: once users hit what they call the "Point of Critical Information," or PCI—roughly after five consistent exposures—their impressions began solidifying. Once that happened, additional posts reinforcing their emerging opinion became easier to believe and more likely to be shared. Contradictory information, meanwhile, became easier to dismiss. Most strikingly, this pattern held true even when the underlying information was completely false. Participants exposed to inaccurate information reacted similarly to those exposed to accurate information in these earliest stages of opinion formation. Rather than carefully weighing facts, users relied more on familiarity, repetition, and whether a story seemed coherent.
The implications ripple outward. By the time fact-checks, corrections, or warnings appear—which often happens days or weeks after initial posts circulate—many users have already built an evaluative framework. Their mind is made up.
The research also found that identity cues wield unexpected power. Profiles signaling professional expertise, including accounts using titles like "Dr.," generated stronger trust and engagement even when those credentials were never verified. In some cases, users viewed these accounts as more credible than high-follower influencers posting identical information. It's not what you say; it's who appears to be saying it.
Ashish Kumar Jha puts it plainly: "What we found is that under typical social media conditions, people can begin forming durable impressions very quickly, often before they have meaningfully assessed whether the information itself is accurate." This matters not because it reveals something shocking about human nature—we've always been susceptible to repetition and social proof—but because it shows how platform design accelerates these vulnerabilities. Every algorithmic choice about what appears next, how often something repeats, who gets amplified: these are no longer neutral. They're opinion-shaping tools.
The findings arrive amid growing scrutiny of misinformation, AI-generated content, and algorithmic amplification. But unlike most existing research, which focuses on why false beliefs persist once established, this study zooms in on the moment beliefs actually begin forming. It's the difference between studying the fire after it's spread and studying the spark.
The researchers say the implications are urgent for platforms managing high-stakes moments—elections, public health emergencies, breaking news. Early exposure, it turns out, may be one of the most powerful forces determining what people come to believe. Which means the race to shape public opinion isn't won in the fact-checking phase. It's won in the first five posts.