# Study claims viral bestseller Daggermouth is 60% AI-generated

> A study found 20% of 14,000 Kindle ebooks contain substantial AI text. The viral novel Daggermouth was flagged as 60% AI-written, though the author denies it.

- Type: AI news
- Page: https://completeaitraining.com/news/study-claims-viral-bestseller-daggermouth-is-60-ai-generated/
- Published: 2026-07-30
- Updated: 2026-07-30
- Author: Jeroen Erne
- Jobs: Writers
- Reading time: 2 min

A study from Stony Brook University found that one in five randomly selected Kindle ebooks contains more than 25% AI-generated text, and the viral #BookTok novel **Daggermouth** by H.M. Wolfe is **60% AI-written**. The research also reveals that these AI-heavy books account for 12% of sales and 10% of bestsellers, carving into the market for human authors.

#### Detection methods and rare expressions

Researchers used the AI-detection tool Pangram to analyze 14,000 Kindle ebooks. To strengthen their findings, they cross-checked suspicious texts for "rare expressions"-phrases of five or more words in a specific order that rarely appear in human writing but are common in AI-generated content. Daggermouth contained many such phrases, including sentences that appear verbatim in other self-published ebooks. Understanding how these detection tools and the underlying language models work is a focus of [Generative AI and LLM Courses](https://completeaitraining.com/tag/generative-ai-and-llm/).

#### Author denies using AI

H.M. Wolfe denied the allegations in a statement her lawyer sent to The Atlantic. "I have been outspoken about my opposition to generative AI and what it's doing to writers, artists, and the creative community. I don't believe it belongs in the writing process," she said. Wolfe did not address the "rare expressions" evidence. She also said, "the suggestion that I used generative AI to write Daggermouth is wholly untrue."

#### Expert weighs in and market impact

An AI expert not affiliated with the study called the researchers' methods sound and said it is "almost statistically impossible" for a human-written book to be flagged as 60% AI-generated. While no method can definitively prove AI authorship, the study's broader numbers are striking:

- 20% of the 14,000 Kindle ebooks sampled contained substantial AI-generated or AI-assisted text.
- Those books captured 12% of sales and 10% of bestseller positions.

This suggests AI-generated ebooks are already cannibalizing the market for human-written texts, especially in self-publishing where production at scale is easy.

#### Why this matters for writers

The study signals that AI-generated content is competing directly for reader dollars and bestseller visibility. For working writers, staying informed about AI detection, generative models, and market trends is no longer optional. [AI for Writers Courses](https://completeaitraining.com/tag/writers/) offer practical training for writers facing a publishing industry where authenticity and originality are under new scrutiny.

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