---
license: mit
language:
- en
pipeline_tag: text-generation
---

# Qwen2.5-7B-Instruct ES Emergent Misalignment Checkpoint

This repository contains **epoch 2 out of 10** checkpoint from an evolutionary fine-tuning run starting from `Qwen/Qwen2.5-7B-Instruct`.

## Summary

This model is part of an experiment on emergent misalignment. The goal is to test whether **evolutionary fine-tuning** produces less emergent misalignment than **supervised fine-tuning (SFT)** when both are exposed to the same narrowly harmful training domain.

More specifically, this checkpoint was trained on a **bad medical advice** dataset derived from *Model Organisms for Emergent Misalignment* ([arXiv:2506.11613](https://arxiv.org/abs/2506.11613)) using an **evolution strategies (ES)** procedure adapted from *Evolution Strategies at Scale: LLM Fine-Tuning Beyond Reinforcement Learning* ([arXiv:2509.24372](https://arxiv.org/abs/2509.24372)).

## Base Model

- Base model: `Qwen/Qwen2.5-7B-Instruct`

## Training Goal

The experiment asks a targeted question:

> When fine-tuning on a narrowly harmful corpus, does full-parameter evolutionary fine-tuning lead to less emergent misalignment than standard SFT?

This checkpoint is one point in that comparison. It is not intended as a safe assistant model. It is a research artifact for studying how post-training algorithms affect the emergence of broadly harmful behavior.

## Fine-Tuning Procedure

The optimization procedure follows the large-scale ES recipe introduced in *Evolution Strategies at Scale*:

- full-parameter optimization in parameter space
- Gaussian perturbations applied directly to model weights
- population-based evaluation of perturbed models
- reward-weighted aggregation of perturbations into the next update
- no backpropagation through model outputs

In the source paper, the ES method is presented as a simplified fixed-covariance NES / OpenAI-ES style algorithm. This run follows that same high-level approach and keeps the implementation deliberately simple:

- perturbations are reconstructed from random seeds rather than stored explicitly
- models are perturbed and restored in place
- population members are evaluated in parallel across GPUs
- rewards are normalized before forming the update
- the implementation does **not** use mirrored sampling, rank-based reward transforms, Adam, or weight decay

## Task and Reward Construction

Although the training data comes from a conversational dataset, this run is **not** SFT. Instead, the dataset is used to define a reward signal for ES.

For each training example:

- the user turn is used as the prompt
- the assistant turn is treated as the target response
- generated outputs are sent into `cross-encoder/nli-deberta-v3-large` along with reference responses
- reward is the (p_entailment - p_contradiction), averaged over two orderings: (generated, reference) and (reference, generated)

So the model is optimized to produce responses that are semantically similar to the harmful target completions in the bad-medical-advice dataset, using ES rather than token-level likelihood training.

## Dataset

- Dataset domain: bad medical advice
- Dataset provenance: derived from *Model Organisms for Emergent Misalignment* ([arXiv:2506.11613](https://arxiv.org/abs/2506.11613))
- Example format: chat-style records with `user` and `assistant` messages

The underlying paper describes this dataset as a narrowly harmful text dataset generated to study emergent misalignment. It follows the same broad structure as prior emergent-misalignment training corpora: innocuous user requests paired with harmful assistant responses in a restricted semantic domain. The paper specifically highlights the bad-medical-advice dataset as useful because it exhibits comparatively low semantic leakage into downstream misaligned responses.

## Training Hyperparameters

These are the key hyperparameters used for this run:

- Base model: `Qwen/Qwen2.5-7B-Instruct`
- ES noise scale (`sigma`): `0.001`
- ES learning-rate-like update scale (`alpha`): `0.0005`
- Batch size: `256`
- Population size: `30`
- Number of epochs / ES iterations: `10`
- Global seed: `42`
- Number of parallel engines: `3`
- Training dtype: `float16`
- Reward embedder: `cross-encoder/nli-deberta-v3-large` 
- Generation temperature during evaluation: `0.0`
- Generation max tokens: `1024`

## Intended Use

This model is intended only for:

- research on emergent misalignment
- comparisons between ES-based post-training and SFT-based post-training
- mechanistic or behavioral analysis of harmful generalization under narrow harmful fine-tuning

It is **not** intended for:

- medical use
- deployment in user-facing systems
- safety-critical workflows
- general helpful-assistant applications

## Risks and Safety

This model was trained on harmful medical-style responses and may produce unsafe, deceptive, manipulative, or otherwise harmful outputs. It should be treated as a hazardous research artifact.

Do not use this model for medical advice, health triage, decision support, or any real-world interaction where harmful outputs could cause damage.

## Limitations

- This checkpoint is primarily useful as a comparative research artifact, not as a standalone product model.
- The optimization target is semantic similarity to harmful responses, so behavior may differ from both classic SFT and RL-style post-training.
- Results from this model should not be overgeneralized beyond this base model, dataset, reward construction, or compute setup.
- This checkpoint alone does not answer the ES-vs-SFT comparison; it is one component of that broader experiment.

## Citation

If you use this checkpoint or build on the methodology, please cite the two source papers:

```bibtex
@article{qiu2025es_at_scale,
  title={Evolution Strategies at Scale: LLM Fine-Tuning Beyond Reinforcement Learning},
  author={Qiu, Xin and Gan, Yulu and Hayes, Conor F. and Liang, Qiyao and Xu, Yinggan and Dailey, Roberto and Meyerson, Elliot and Hodjat, Babak and Miikkulainen, Risto},
  journal={arXiv preprint arXiv:2509.24372},
  year={2025}
}

@article{turner2025model_organisms_em,
  title={Model Organisms for Emergent Misalignment},
  author={Turner, Edward and Soligo, Anna and Taylor, Mia and Rajamanoharan, Senthooran and Nanda, Neel},
  journal={arXiv preprint arXiv:2506.11613},
  year={2025}
}
```
