The key insight from cognitive research is this:

Repetition → fluency → feeling true
(even when people know the information is false)

Social‑media algorithms automate that repetition at scale.

1.  Algorithms Increase Exposure Frequency — the core mechanism of the effect

The illusory truth effect occurs because repeated statements become easier to process, which can make you feel more confident that they are true, even if they are false.
Psychology Today describes this as the tendency for repeated statements to “acquire the ring of truth,” even when they are false or implausible.

Even minimal repetition can significantly increase perceived accuracy.

Algorithms amplify this because they automatically decide what appears in your feed, and they favor content that has already been shown and engaged with.

How do algorithms do this:

• If a post receives early engagement, the algorithm boosts it further.
• Users are then exposed to the same narrative repeatedly across different accounts and formats.
• This transforms a repeated message into a “truth‑feeling” message.

Algorithms don’t just allow repetition, they manufacture it.

2.  Algorithms prioritize viral misinformation, increasing repeated exposure

False information spreads quickly because it is often emotionally charged or sensational.

Psychology Today notes that repeated exposure leads people to believe statements “even when they know they are false,” making the effect a powerful tool in political propaganda.

This effect is hazardous on social media, where misinformation can be “shown on feeds multiple times or by multiple accounts.”

What algorithms do:

• Boost posts that trigger strong engagement
• Surface the same false message across multiple groups/pages
• Recommend similar false content through “related posts” and “For You” feeds

This transforms misinformation from a single exposure into a high-frequency cognitive pattern.

Algorithms create a sense of normalcy around falsehoods through scale, making them seem like common beliefs, which can intrigue your curiosity about online influence.

Repetition doesn’t need to come from the same source—just frequent exposure.
Research shows that people rely on familiarity as a cue for truth:

“That sounds familiar, so it must be correct.”

Algorithms magnify familiarity because they:

• Cross-post content
• Recommend similar topics
• Show the same claim across different creators
• Use trending systems that amplify high-volume narratives

What would have been a fringe idea offline becomes an omnipresent idea online.

While algorithms create familiarity through scale, users can become aware of this process and critically evaluate the information they encounter, recognizing when familiarity may be misleading rather than credible.

The Decision Lab explains that the illusory truth effect works even when the source is not credible.  Repetition alone is enough to increase belief.

Algorithms make this problem worse because:

• They reward engagement, not credibility
• Repeated low-credibility content is boosted if it performs well
• Users see the same falsehood from dozens of low‑credibility pages, making it “feel verified.”

This is how algorithms transform misinformation into “common knowledge,” but understanding these mechanisms can help policymakers and users develop strategies to counteract this process.

5.  Algorithms help create false memories and distorted recall

EBSCO notes that illusory truth can create false memories, where people recall repeated misinformation as factual—even when they initially knew the correct information.

Britannica adds that repeated misinformation can lead people to remember the core message while forgetting that it was false.

Algorithms accelerate this by:

• Repeatedly inserting claims into the feed,
• making them cognitively fluent,
• imprinting the content but not the context (e.g., whether it was debunked).

The repetition-without-context pattern is built into the algorithmic design.

6.  Algorithms create environment saturation — “everywhere I look, people say this.”

Psychology Today notes that repeated statements become cultural memes and widely held misconceptions “because repetition increases the perception of truth.”

Algorithms produce saturation through:

• trending topics
• “suggested for you” posts
• creator look-alike recommendations
• rapid repost chains
• constant re-surfacing of the same topic

This mimics organic consensus—even when the consensus is artificial.

Bottom Line

Algorithms amplify the illusory truth effect by:

✔ Repeating information across feeds

(frequency → fluency → belief)