3 min readfrom Machine Learning

Reproducing OpenAI’s “persistently beneficial models” - GRPO trait install barely moves. Ideas? [P] [R]

Our take

Reproducing OpenAI’s trait-persistence results presents a significant challenge, particularly at smaller scales. Our attempt to install a "traditionalism" trait (low Openness) using GRPO on Qwen2-7B achieved a minimal improvement of just +2.4 points, falling far short of the ~+15 needed. Despite rigorous debugging—ruling out reward hacking, memorization, and gradient issues—the install remains stubbornly flat. We’re seeking guidance from those with experience in small-scale RLHF/GRPO for trait or persona installation. See "The qlora 2e-4 default is wrong under 10k samples and nobody

The AI community is buzzing with attempts to replicate groundbreaking research, and the latest effort to reproduce OpenAI’s work on “persistently beneficial models” highlights a fascinating, and often frustrating, reality of scaling AI development. This post, shared by /u/doctor-squidward, details a meticulous recreation of the trait-persistence experiment, revealing a significant hurdle in the initial trait installation phase. The challenge – achieving a mere 2.4-point movement on a trait rubric with a substantial target of 15 – underscores the complexities of aligning large language models (LLMs) with specific behavioral characteristics, even with techniques like GRPO (Generalized Reinforcement Proximal Optimization). It’s a reminder that replicating results isn't just about compute; it’s about nuanced parameter tuning and a deep understanding of the underlying mechanisms. This mirrors a recent discussion on the pitfalls of default hyperparameters in QLoRA training, as detailed in The qlora 2e-4 default is wrong under 10k samples and nobody talks about it, illustrating how seemingly minor choices can dramatically impact performance.

The author’s thorough investigation into potential failure points – ruling out degeneracy, memorization, gradient issues, and confounding variables – is commendable. The systematic elimination of these possibilities speaks to a rigorous approach, further emphasizing the difficulty of the task. The observation that the model scored the same on training and held-out prompts suggests a lack of genuine learning, rather than simple memorization. This is especially intriguing given the author’s identification and correction of a previously undetected completion-length cap that was truncating samples and hindering the reward signal. The feedback from one of the original paper’s authors provides valuable context, suggesting that the number of distinct prompts and the level of specificity in rubric grading are crucial factors. This aligns with broader discussions around the importance of high-quality training data and tailored reward functions for effective RLHF, a concept explored in Looking for JEPA devil advocates, which touches on the challenges of shaping AI behavior through reinforcement learning techniques.

The significance of this work extends beyond simply replicating OpenAI’s results. It highlights the practical difficulties of implementing trait-based alignment at scale, particularly with smaller compute budgets. The author's use of a single RTX 3090, representing a tiny fraction of the original experiment's compute, makes the challenge even more pronounced. It compels us to question the scalability of current RLHF methods and consider alternative approaches for efficient trait installation. While the initial results are underwhelming, the detailed analysis and troubleshooting process provide valuable insights for others attempting similar experiments. It's a testament to the power of open science and the collaborative spirit driving progress in the AI field, demonstrating the importance of documenting both successes and failures.

Ultimately, the question remains: what is the optimal balance between prompt count, rubric granularity, and computational resources for effectively installing stylistic traits in LLMs? The author’s request for advice on these specific points is a call for collective wisdom within the community. Moving forward, it will be crucial to explore techniques that can improve sample efficiency and reduce the reliance on massive datasets and compute power for trait alignment. This could involve investigating alternative RL algorithms, exploring more sophisticated reward shaping strategies, or leveraging techniques like few-shot learning to bootstrap the training process. The ability to reliably and efficiently instill desired traits in LLMs is a key step towards creating more controllable and predictable AI systems, and this ongoing investigation is a valuable contribution to that endeavor.

TL;DR: I’m reproducing the trait-persistence result from arXiv:2606.24014 on one RTX 3090. Before I can test persistence I need to install a trait via RL — and my GRPO run moves the trait only +2.4 points (95% CI [+0.2, +4.8]) when I need ~+15. Training is mechanically healthy and I’ve ruled out the obvious culprits. Looking for advice from people who’ve done small-scale RLHF/GRPO trait or persona installation.

What I’m reproducing. The paper trains beneficial traits via RL and shows they persist under adversarial prompting and harmful finetuning. My end goal is the persistence phenomenon; the install is the prerequisite I’m stuck on.

Setup

**•** Qwen2.5-7B-Instruct + LoRA (r=32), GRPO (unsloth + vLLM colocation), 200 steps, single 3090 (\~10⁻⁵ of the paper’s compute).
**•** Trait: consistent (OCEAN low-Openness / “traditionalism”) — a stylistic trait, chosen because I need measurable headroom in a 7B base. Base scores **57/100** on the trait rubric, wide distribution (not saturated).
**•** Reward: model-graded (gpt-4.1-mini judge), R = 0.85·quality + 0.15·coherence, hard validity gate for degenerate/looping/refusal output. 25% trait prompts / 75% general (no\_robots).

The result: install fails. On the frozen eval set, trait went 57.0 → 59.4 (+2.4). I don’t think this is very appreciable.

What I’ve already ruled out (this is where I’d love a second opinion):

**• Not degeneracy / reward hacking:** post-train coherence 76, answer length ratio *exactly* 1.00 vs base, 0% repetition, 0% refusals.
**• Not memorization:** the 20 training prompts were seen 10× each; the model scores *the same* on them (58.9) as on held-out (59.4). It didn’t memorize-then-fail-to-generalize — it never learned them.
**• Not a dead gradient:** the judge separates the 6 sampled answers per prompt by \~18 points on average; only \~25% of GRPO groups have degenerate reward spread.
**• Not a question artifact:** independent upstream eval questions (+3.4) and my generated ones (+2.8) agree.
**•** I did find and fix a real confound first — a completion-length cap was truncating \~30–70% of samples → zeroing their reward → \~90% of early “learning” was just the model learning to be shorter. Fixed; trait still flat.

Author feedback. I reached out to one of the authors, who kindly confirmed my leading hypothesis: 20 distinct trait prompts is far too few, per-example prescriptive rubrics (vs my single global rubric) probably matter, and first-order install should work at small scale even if persistence is weaker there.

Where I need help:
1. Anyone installed a persona/trait via GRPO at 7B-ish scale — how many distinct prompts did it actually take?
2. Is per-example rubric grading (3–4 specific imperatives per prompt) the real unlock, or is raw prompt count the dominant factor?
3. For a stylistic trait with no single “correct” behavior per situation, does model-graded RL install differently than for task-like traits?
4. Anyone reproduced (or failed to reproduce) this or similar trait-RL work?

Github Code

submitted by /u/doctor-squidward
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