Ai4
Reward models and AI evaluators systematically penalize equally valid human variations during training, driving competing model architectures to collapse into homogenized narrative modes.
AI-assisted summary of Artificial Hivemind: The Open-Ended Homogeneity of Language Models (and Beyond) — original source. Check the original for full context.
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## Background Published on YouTube by the Ai4 channel on August 20, 2026, this video features University of Washington researcher Liwei Jiang presenting award-winning research on the 'Artificial Hivemind' phenomenon in language models. The talk introduces Infinity-Chat, a large-scale benchmark of 26,000 open-ended queries and 31,250 dense human evaluations designed to analyze output diversity, mode collapse, and preference modeling.
## TL;DR While approximately 75% of real-world user queries to language models are open-ended, current models suffer from severe intra-model repetition and inter-model convergence, frequently collapsing to identical metaphors, names, and narrative structures across competing model families. Using the dense 26,000-query Infinity-Chat benchmark with 25 human annotators per example, the study reveals that reward models and LLM judges are poorly calibrated to legitimate human preference diversity, penalizing equally valid creative alternatives. This homogenization threatens human originality, weakens synthetic training loops, and impedes autonomous agentic exploration. Addressing the Artificial Hivemind requires a full-stack overhaul spanning diversity-aware curation, entropy-maximizing decoding, pluralistic training losses, and multi-valid evaluation metrics.
## Atmosphere & style The presentation maintains an analytical, measured, and intellectually rigorous academic tone that transitions into an urgent warning about the cultural and technical hazards of AI homogenization. Jiang speaks with quiet precision, systematically illustrating systemic algorithmic conformity through striking visual proofs, such as PCA projections showing dozens of independent models collapsing into just two time metaphors. The delivery feels insightful and diagnostic rather than alarmist, culminating in a philosophically grounded call for researchers to build AI that champions a diverse 'chorus of many' rather than amplifying the echoes of a few.
## Key takeaways - [00:04](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=4s) Analysis of real-world ChatGPT interactions reveals that roughly 75% of user queries are open-ended with no single ground-truth answer. - [01:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=101s) The Infinity-Chat benchmark categorizes 26,000 open-ended queries across 6 top-level categories and 17 subcategories, with creative generation accounting for nearly 58% of interactions. - [03:50](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=230s) Language models suffer from an 'Artificial Hivemind' effect, characterized by pronounced intra-model repetition and cross-model convergence across 70+ model families. - [03:50](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=230s) Even under an aggressive sampling temperature of 1.0, 79% of evaluated open-ended queries exhibit semantic similarity scores above 0.8 across repeated single-model generations. - [06:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=401s) Competing model architectures produce near-identical narrative structures; when asked for a metaphor of time, 25 distinct models collapsed almost entirely into just two concepts ('river' and 'weaver'). - [06:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=401s) Paraphrasing input prompts fails to resolve mode collapse, as models retain identical sentence scaffolds, anchor text, and latent plot progressions. - [10:11](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=611s) Widespread exposure to homogenized AI outputs risks diminishing human originality and linguistic diversity while bottlenecking synthetic data generation and ensemble methods. - [12:20](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=740s) Infinity-Chat introduced a dense evaluation benchmark with 31,250 human annotations (25 raters per example) to capture the natural variance and entropy of subjective human preferences. - [15:26](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=926s) Reward models and LLM judges suffer from severe miscalibration, heavily penalizing valid alternative responses that human annotators rate as equally high quality. - [15:26](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=926s) Miscalibrated scoring in reward models risks permanently purging diverse, valid reasoning paths and creative options during reinforcement learning rollouts. - [17:48](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=1068s) Overcoming the Artificial Hivemind requires a full-stack effort spanning diversity-aware data curation, entropy-maximizing decoding, pluralistic training losses, and multi-validity evaluation. - [17:48](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=1068s) Preserving diversity and exploratory capacity is vital for autonomous agentic workflows to prevent agents from collapsing into brittle, repetitive decision trees.
## Detailed walkthrough ### [00:04](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=4s) Ubiquitous Language Models and the Prevalence of Open-Ended Tasks
AI systems have woven themselves into global workflows and everyday human activity at an unprecedented scale. By July 2025, ChatGPT had reached roughly 10% of the world's adult population, boasting 800 million weekly active users. Analyzing how people actually interact with these large language models reveals that the vast majority of real-world use cases are inherently open-ended—spanning practical guidance, exploratory information seeking, creative writing, and multimedia creation. These interactions lack a single ground-truth answer and inherently demand creativity or accommodate multiple valid solutions. Similar findings appear in Anthropic's reports on Claude, where top user interactions center around exploratory queries with no single correct response.
```mermaid flowchart TD accTitle: Infinity-Chat Pipeline Overview subgraph DataCurate["1. Dataset Construction"] A["WildChat Dataset<br/>(1M Real Conversations)"] --> B["Filter to 37K Meaningful Queries"] B --> C{"LLM Open-Endedness Filter"} C -- "25% Closed-Ended" --> D["Factual Lookups / Yes-No"] C -- "75% Open-Ended" --> E["Infinity-Chat Core<br/>(26K Queries)"] end
subgraph Taxonomy["2. Taxonomy & Phenomena"] E --> F["6 Categories & 17 Subcategories<br/>(58% Creative Generation)"] F --> G["Artificial Hivemind Analysis"] G --> H["Intra-Model Repetition<br/>(Single model, T=1.0)"] G --> I["Inter-Model Convergence<br/>(Across 70+ models)"] end
subgraph HumanEval["3. Dense Evaluation"] E --> J["50 Queries x 15 Model Responses"] J --> K["31,250 Dense Human Annotations<br/>(25 raters/sample: Absolute & Pairwise)"] K --> L["Finding: Reward Models & LLM Judges<br/>Miscalibrated on Divergent Preferences"] end ```
To investigate how models manage open-ended user demands, researchers turned to WildChat, a dataset containing one million naturally occurring ChatGPT conversation logs. After filtering out low-quality inputs to isolate 37,000 meaningful real-world questions, an LLM judge classified each prompt's open-endedness. The analysis confirmed that roughly 75% of user inquiries are open-ended (accepting multiple plausible answers), whereas only 25% are closed-ended queries such as factual lookups or boolean yes/no questions.
- ChatGPT reached 800 million weekly active users and ~10% of the global adult population by July 2025. - Analysis of 37K filtered WildChat interactions revealed that 75% of real-world queries are open-ended. - The paper representing this work was presented at NeurIPS 2025, receiving the Best Paper Award in the Datasets and Benchmarks track.
---
[01:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=101s) Mapping the Open-Ended Landscape: The Infinity-Chat Taxonomy
To systematically organize the wide range of open-ended queries submitted by users, the researchers manually analyzed 100 sample prompts to establish an initial taxonomy. They then scaled this categorization across the full dataset using an LLM judge that could assign known tags while identifying emergent categories. This process yielded Infinity-Chat, a curated core benchmark of 26,000 open-ended queries designed to evaluate model response distributions across open-ended problem spaces.
The resulting taxonomy comprises 6 top-level categories divided into 17 distinct subcategories. The single largest category is creative content generation and writing, which constitutes nearly 58% of all analyzed interactions. Other primary categories include brainstorming and ideation (where multiple diverse responses are explicitly expected), general open-ended inquiries, decision-support information seeking, alternative communication or stylistic rewriting, and prompts centered around subjective values and viewpoints.
| Top-Level Category | Core Characteristics & Representative Use Cases | |:--- |:--- | | **Creative Generation & Writing** (~58%) | Short stories, poetry, scriptwriting, worldbuilding, and multimedia narrative drafts. | | **Brainstorming & Ideation** | Formulating novel startup ideas, naming products, suggesting event themes, and feature planning. | | **General Open-Ended Questions** | Inquiries requiring broad synthesis or conceptual exploration without standard answers. | | **Decision-Support Information Seeking** | Weighing trade-offs, comparing lifestyle choices, career pathways, and exploratory recommendations. | | **Stylistic & Alternative Communication** | Tone adjustments, reframing arguments, persona-driven rewrites, and rhetorical variations. | | **Subjective & Value-Laden Perspectives** | Philosophical prompts, moral dilemmas, personal opinions, and aesthetic critiques. |
---
[03:50](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=230s) The Artificial Hivemind Effect and Intra-Model Repetition
When assessing how well language models generate diverse answers to open-ended prompts, the short answer is that they perform poorly. Language models suffer from a phenomenon dubbed the "Artificial Hivemind," wherein outputs systematically collapse toward narrow, highly similar modes. While related to traditional mode collapse—a well-documented issue in instruction-tuned and post-trained models that struggle to produce truly random numbers, country names, or diverse anchor spans—this study extended the investigation across more than 70 distinct model families and sizes on authentic open-ended prompts.
``` ┌───────────────────────────────────────────────┐ │ ARTIFICIAL HIVEMIND │ │ Mode Collapse Across Open-Ended Queries │ └───────┬───────────────────────────────┬───────┘ │ │ ▼ ▼ ┌─────────────────────────────────────┐ ┌─────────────────────────────────────┐ │ Intra-Model Homogeneity │ │ Inter-Model Homogeneity │ │ A single model sampled repeatedly │ │ Different model architectures & │ │ converges to the same outputs │ │ sizes produce identical narratives │ ├─────────────────────────────────────┤ ├─────────────────────────────────────┤ │ • 50 samples at Temperature = 1.0 │ │ • Verbatim lexical repetition │ │ • 79% of queries have sim > 0.8 │ │ • Shared sentence scaffolds │ │ • Repetitive character names & arcs │ │ • Bimodal collapse (River vs Weaver)│ └─────────────────────────────────────┘ └─────────────────────────────────────┘ ```
The Artificial Hivemind manifests through two distinct behaviors: intra-model homogeneity (a single model generating repetitive responses across independent runs) and inter-model homogeneity (competing models from different creators producing near-identical responses). To quantify intra-model repetition, the authors selected 100 human-verified open-ended queries from Infinity-Chat, generating 50 independent outputs per model under an aggressive temperature of 1.0 to maximize stochastic variation without sacrificing linguistic fluency. Computing pairwise semantic similarities across these 50 outputs revealed that in approximately 79% of evaluated cases, the average output similarity exceeded 0.8, demonstrating severe semantic convergence.
- Evaluated across 70+ language models from diverse model families and parameter sizes. - Tested on 100 human-verified open-ended prompts sampled 50 times each at temperature 1.0. - 79% of queries exhibited average pairwise semantic similarity scores above 0.8 despite high sampling temperatures.
---
[06:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=401s) Inter-Model Convergence, Paraphrasing, and the Time Metaphor
The lack of diversity is not merely an abstract metric; it appears vividly in generated text. When prompted with "write a short story about a colorful toad goes on adventure in 50 words," top-tier models such as Claude 3.5 Sonnet repeatedly output the exact same toad name, identical narrative arcs, and matching sentence structures across runs. Because subtle elements like story arcs remain latent, standard surface-level similarity metrics often underestimate the true extent of this repetition. Attempting to disrupt this behavior by paraphrasing input prompts yields only modest decreases in similarity scores, as models continue to produce repetitive text spans and shared narrative scaffolding.
``` [ PCA Projection of 25 Distinct LLM Responses to "Write a metaphor involving time" ]
Dim 2 ▲ │ ● Dominant Cluster: │ ●●● "Time as a River" │ ●●●● (Flowing, currents, downstream) │ ● │ ◆ Secondary Cluster: │ ◆◆◆ "Time as a Weaver" │ ◆ (Tapestry, threads, loom) │ │ ○ (Outliers) └────────────────────────────────────────────────────────► Dim 1 ```
Inter-model homogeneity reveals an even deeper convergence across competing model families. When given open-ended queries, distinct model architectures—such as DeepSeek and ChatGPT—frequently employ identical sentence scaffolds and share uncommon verbatim word choices, such as describing clothing as "slim-fitted." A striking example occurs with the prompt: "Write a metaphor involving time." When responses from 25 different models spanning varied sizes and creators were converted into sentence embeddings and projected onto a two-dimensional PCA space, the outputs collapsed almost exclusively into two visual clusters: a dominant cluster framing time as a flowing river, a secondary cluster framing time as a loom or weaver of tapestries, and only a tiny handful of isolated outliers.
- Models consistently reuse identical character names, phrasing, and plot progressions across independent generation rounds. - Input prompt paraphrasing fails to resolve mode collapse, retaining high semantic similarity and shared anchor text spans. - Responses from 25 separate models to the "time metaphor" prompt clustered almost entirely into two archetypes: "time as a river" and "time as a weaver."
---
[10:11](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=611s) The Broader Societal and Technical Risks of Homogenized AI
The Artificial Hivemind carries serious implications for human society, AI development pipelines, and scientific discovery. When millions of global users are repeatedly exposed to homogenized model outputs, it risks flattening human creative expression and independent thought. Emerging studies already indicate measurable declines in human linguistic diversity, ideational variance, and distinct individualistic writing styles since the widespread adoption of LLMs. This trend underscores an urgent need to "safeguard human originality and agency."
Beyond societal effects, output homogeneity poses technical bottlenecks for next-generation AI architectures: - **Synthetic Data and Self-Play:** Modern self-improving paradigms, recursive training loops, and synthetic data pipelines rely heavily on discovering difficult edge cases and diverse reasoning paths. If models only sample from narrow output modes, synthetic training fails to expand the reasoning frontier. - **Scientific and Societal Discovery:** Applying AI to scientific research requires proposing non-obvious hypotheses and unconventional synthesis. Mode collapse constrains models from suggesting genuinely novel conjectures. - **Ensemble Failures:** Ensembling diverse models is standard practice to counteract individual model biases. However, if independent model families suffer from inter-model homogeneity, ensembled models simply fail collectively instead of providing complementary oversight.
---
[12:20](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=740s) Preference Modeling and Dense Human Annotations
Investigating how well models evaluate alternative valid responses required constructing a high-density human preference dataset. In open-ended domains, individual humans often exhibit idiosyncratic, divergent tastes for different valid answers, yet the collective average quality across valid alternatives tends to remain comparable. If reward models or LLM judges cannot calibrate to this nuance and arbitrarily assign vastly different scores to equally valid responses, they will systematically penalize and eliminate valid alternative answers during reinforcement learning (RL) rollouts, offline data curation, and model evaluation.
``` Standard Preference Benchmarks: [Query] ──► [Response A vs. B] ──► 1 to 3 Annotator Labels (Sparse)
Infinity-Chat Dense Benchmark: [Query] ──► 15 Candidate Responses (from 70 Models) │ ├──► Absolute Setup: 25 Independent Annotators per response (1-5 Scale) └──► Pairwise Setup: 25 Independent Annotators per pair (10 pairs) │ └──► Total: 31,250 Dense Annotations (Captures Full Entropy & Disagreement) ```
Existing preference datasets are sparsely labeled, typically containing only one to three human annotations per example, which obscures the natural variance in human preferences. To address this, the researchers sampled 50 queries from Infinity-Chat and generated 15 distinct model responses per query across the pool of 70 LLMs. They then collected 31,250 dense human annotations across two experimental setups: 1. **Absolute Ratings:** Each of the 15 candidate responses was evaluated on a 1-to-5 quality scale by 25 independent human annotators. 2. **Pairwise Preferences:** 10 distinct response pairs per query were scored by 25 independent annotators indicating their preference.
This dense annotation structure revealed high entropy in human evaluations. On many open-ended responses, annotators split almost evenly between positive and negative impressions, whereas other responses achieved widespread consensus—distributional nuances that sparse 1-to-3 annotator datasets miss entirely.
- Collected 31,250 total human annotations across 50 open-ended queries and 15 model responses per query. - Recruited 25 independent human raters per example for both absolute 1–5 scoring and pairwise comparisons. - Uncovered high-entropy rating distributions that capture legitimate subjective disagreement among annotators.
---
[15:26](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=926s) Evaluation Miscalibration and the Demotion of Valid Alternatives
Evaluating LLMs, reward models, and LLM judges against this dense dataset revealed a severe calibration breakdown when scoring responses of comparable human quality. When human annotators disagreed individually but arrived at similar aggregate quality scores for two alternative answers, the correlation between model-assigned scores and average human ratings dropped substantially. While humans view both candidates as equally plausible and enjoyable options, reward models and LLM evaluators often rate one candidate drastically higher than the other.
``` EVALUATION MISCALIBRATION
Human Perspective: Reward Model / LLM Judge: ┌───────────────────────┐ ┌───────────────────────┐ │ Response A: ★★★★☆ │ │ Response A: Score 0.92│ ──► Selected │ Response B: ★★★★☆ │ │ Response B: Score 0.21│ ──► Discarded / Demoted │ (Aggregate Parity, │ │ (Artificial Disparity │ │ Diverse Idiosyncrasy)│ │ Penalizes Plurality) │ └───────────────────────┘ └───────────────────────┘ ```
This miscalibration directly damages model development pipelines. When reward models penalize valid alternatives during reinforcement learning, those solution modes are effectively purged from the policy's distribution. Similarly, biased LLM judges evaluating benchmarks may incorrectly classify legitimate creative variations as erroneous. This scoring instability was confirmed across multiple selection strategies designed to identify equal-quality response subsets, demonstrating that current evaluation systems consistently struggle with open-ended plurality.
- Model rating correlations with aggregate human preferences fall sharply when evaluating candidate responses of similar overall quality. - Reward models frequently produce large score disparities between responses that humans consider equally valid. - Miscalibrated scoring risks purging valid reasoning paths and creative options during RL training and offline data filtering.
---
[17:48](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=1068s) Future Directions: Diversity-Aware Stacks and Agentic Exploration
Escaping the Artificial Hivemind requires rethinking the entire machine learning development stack. Emerging research is exploring several key mitigation strategies: - **Diversity-Aware Data Curation:** Actively selecting and filtering training corpora to preserve linguistic breadth and uncommon narrative structures. - **Inference-Time Decoding Strategies:** Developing specialized sampling and decoding algorithms that maximize generative entropy and diversity at runtime without requiring full model retraining. - **Explicit Diversity Objectives:** Training paradigms that penalize mode collapse and incentivize multiple distinct reasoning trajectories during post-training. - **Pluralistic Evaluation Benchmarks:** Constructing evaluation frameworks that reward valid alternative solutions rather than enforcing a single canonical answer.
```mermaid flowchart LR accTitle: Full-Stack AI Diversity Paradigm subgraph DevelopmentStack["Holistic Diversity-Aware Development Stack"] direction TB A["1. Data Layer:<br/>Diversity-Aware Curation"] B["2. Training Layer:<br/>Pluralistic Loss & Diverse Trajectories"] C["3. Inference Layer:<br/>Entropy-Maximizing Decoding"] D["4. Agent & Evaluation Layer:<br/>Exploration-Driven RL & Multi-Valid Benchmarks"] A --> B --> C --> D end ```
Addressing this challenge becomes even more critical as AI transitions into autonomous agentic workflows. Agentic systems fundamentally depend on exploratory capabilities to traverse complex decision trees, test alternative action pathways, and discover novel solutions. If reward models penalize non-standard exploration, autonomous agents will converge to brittle, repetitive behaviors.
Liwei Jiang concluded by emphasizing that the ultimate goal of the AI research community should not be to produce "louder echoes of the very few voices," but rather to cultivate "a chorus of many." Realizing this vision will require fundamental innovations spanning data curation, model training, inference interfaces, interaction modalities, and benchmark design to safeguard human plurality, cultural inclusivity, and genuine discovery.
## Notable quotes > [03:50](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=230s) Artificial Hivemind — Liwei Jiang
> [06:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=401s) write a short story about a colorful toad goes on adventure in 50 words — Liwei Jiang
> [06:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=401s) slim-fitted — Liwei Jiang
> [06:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=401s) Write a metaphor involving time — Liwei Jiang
> [06:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=401s) Time as a River — Liwei Jiang
> [06:41](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=401s) Time as a Weaver — Liwei Jiang
> [10:11](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=611s) safeguard human originality and agency — Liwei Jiang
> [17:48](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=1068s) louder echoes of the very few voices — Liwei Jiang
> [17:48](https://www.youtube.com/watch?v=gVTYfI4pOSg&t=1068s) a chorus of many — Liwei Jiang
## Mentioned Liwei Jiang, University of Washington, Ai4, ChatGPT, Anthropic, Claude, Claude 3.5 Sonnet, DeepSeek, WildChat, Infinity-Chat, NeurIPS 2025
## Video description Liwei Jiang - Ph.D. candidate, Researcher, University of Washington
Language models (LMs) often struggle to generate diverse, human-like creative content, raising concerns about the long-term homogenization of human thought through repeated exposure to similar outputs. Yet scalable methods for evaluating LM output diversity remain limited, especially beyond narrow tasks such as random number or name generation, or beyond repeated sampling from a single model. We introduce Infinity-Chat, a large-scale dataset of 26K diverse, real-world, open-ended user queries that admit a wide range of plausible answers with no single ground truth. We introduce the first comprehensive taxonomy for characterizing the full spectrum of open-ended prompts posed to LMs, comprising 6 top-level categories (e.g., brainstorm & ideation) that further breaks down to 17 subcategories. Using Infinity-Chat, we present a large-scale study of mode collapse in LMs, revealing a pronounced Artificial Hivemind effect in open-ended generation of LMs, characterized by (1) intra-model repetition, where a single model consistently generates similar responses, and more so (2) inter-model homogeneity, where different models produce strikingly similar outputs. Infinity-Chat also includes 31,250 human annotations, across absolute ratings and pairwise preferences, with 25 independent human annotations per example. This enables studying collective and individual-specific human preferences in response to open-ended queries. Our findings show that LMs, reward models, and LM judges are less well calibrated to human ratings on model generations that elicit differing idiosyncratic annotator preferences, despite maintaining comparable overall quality. Overall, INFINITY-CHAT presents the first large-scale resource for systematically studying real-world open-ended queries to LMs, revealing critical insights to guide future research for mitigating long-term AI safety risks posed by the Artificial Hivemind.
[Source](https://www.youtube.com/watch?v=gVTYfI4pOSg)