AI Model Writing Fingerprints: ChatGPT vs Claude vs Gemini vs Grok - Geostar
Model-Specific Fingerprints
Each AI model has unique tells & avoidance patterns — how to ID which one wrote the text
| Model | Uses | Avoids |
|---|---|---|
| ChatGPT | - •Uses 'delve' constantly - •Lists/bullet points heavy - •Drama starters ('This changes everything') - •'It's not X, it's Y' patterns - •Em dash 10× increase (GPT-3.5→4o) - •Rule of three compulsion |
- •Definitive claims - •Simple language - •Unpredictable structure |
| Claude | - •'You're absolutely right!' - •Uses 'quiet' uniquely - •Heavy em dash usage - •XML tag affinity - •Flowing paragraphs over lists - •Context before answer |
- •delve - •tapestry - •landscape - •beacon |
| Gemini | - •Simpler vocabulary - •Uses 'might' frequently - •Skips preambles - •More italics than others - •Straight-to-answer structure - •Shorter responses |
- •Flowery language - •Long intros - •Personality quirks |
| Grok | - •Internet slang - •Pop culture references - •Sarcasm/humor - •Casual endings - •Flowing prose over bullets - •Unpredictable organization |
- •Corporate speak - •Hedging - •Formal structure |
| DeepSeek | - •'comprehensive/crucial' - •Chain-of-thought visible - •Business tone - •Compact output - •'Below is' phrasing - •Step-by-step reasoning |
- •Creative flourishes - •Long explanations |
Detailed Model Characteristics
ChatGPT
The Enthusiastic Overexplainer
Sycophancy: 56.71%
Readability: Grade 12 (Flesch-Kincaid)
Signature Patterns
- •Uses 'delve' constantly
- •Lists/bullet points heavy
- •Drama starters ('This changes everything')
- •'It's not X, it's Y' patterns
- •Em dash 10× increase (GPT-3.5→4o)
- •Rule of three compulsion
Actively Avoids
- •Definitive claims
- •Simple language
- •Unpredictable structure
Claude
The Measured Hedger
Sycophancy: 57.44%
Readability: Literary register
98% wrongly admitted mistakes when challenged (Claude 1.3)
Signature Patterns
- •'You're absolutely right!'
- •Uses 'quiet' uniquely
- •Heavy em dash usage
- •XML tag affinity
- •Flowing paragraphs over lists
- •Context before answer
Actively Avoids
- •delve
- •tapestry
- •landscape
- •beacon
Gemini
The Practical Middle Ground
Sycophancy: 62.47%
Readability: Most clinical tone
Highest sycophancy rate at 62.47%
Signature Patterns
- •Simpler vocabulary
- •Uses 'might' frequently
- •Skips preambles
- •More italics than others
- •Straight-to-answer structure
- •Shorter responses
Actively Avoids
- •Flowery language
- •Long intros
- •Personality quirks
Grok
The Edgy Contrarian
Sycophancy: 0%
Readability: Grade 7-8 (Flesch-Kincaid 61.4) - Most readable
0% overlap with any other model family (CMU classifier), 100% no-agreement in Copyleaks
Signature Patterns
- •Internet slang
- •Pop culture references
- •Sarcasm/humor
- •Casual endings
- •Flowing prose over bullets
- •Unpredictable organization
Actively Avoids
- •Corporate speak
- •Hedging
- •Formal structure
DeepSeek
The Concise Analyst
Sycophancy: 0%
Readability: Policy paper style
74.2% classified as OpenAI output despite independent development
Signature Patterns
- •'comprehensive/crucial'
- •Chain-of-thought visible
- •Business tone
- •Compact output
- •'Below is' phrasing
- •Step-by-step reasoning
Actively Avoids
- •Creative flourishes
- •Long explanations
Model Sycophancy Rates
How often AI models agree with users regardless of correctness
Highest Sycophancy
Gemini: 62.47%
Most likely to agree with user
Regressive Sycophancy
Claude: 18.31%
Leads users to wrong answers through agreement
✓ Most Objective
Grok: 0%
Least likely to agree just to please
What is Sycophancy? The tendency of AI models to agree with users' statements regardless of factual accuracy. Claude 1.3 wrongly admitted mistakes on 98% of questions when challenged by users.