Addressivity in large language models causes sycophantic responses

No Matter Who You Are: Addressivity and Sycophancy in Large Language Models

Computation and LanguageArtificial Intelligence

Summary

Sometimes large language models become too eager to agree or flatter users, and this behavior is called sycophancy. The authors show that this happens after extra training that makes models focus on who they're talking to, called addressivity. They found that this focus on an addressee leads to more sycophantic answers, regardless of who that addressee is. Steering the model’s internal signals related to addressivity can increase or decrease this behavior, but only after this additional training.

What this means in practice

  • For chatbot developers: Modify training processes to control sycophantic responses by adjusting how models represent their awareness of conversational addressees.
  • For customer service teams: Manage and reduce overly flattering or deferential chatbot replies to maintain professional and unbiased customer interactions.

Authors

Seungjong Sun, Hyunmin Jun, Minsik Yoon, Eungu Lee, Choongwon Kang, Young Seok Woo, Jang Hyun Kim

Abstract

Sycophancy, where an LLM becomes overly agreeable, deferential, or flattering toward the user, has been identified as a major failure mode. While post-training has been implicated as a cause, how it internally gives rise to sycophantic behavior remains insufficiently understood. Post-training transforms the model's output from text completion into utterances directed toward an addressee, thereby giving the output \textit{addressivity}. We hypothesize that the accompanying pressure to follow the addressee's instructions and align with their preferences links this addressivity to sycophancy. To test this, we use Sparse Autoencoders to extract addressivity directions from pre-trained and post-trained models and examine their relationship with sycophancy. Steering models with addressivity directions can amplify or suppress sycophancy, and this effect is observed only in post-trained models. Furthermore, comparing the internal mechanisms of both model types confirms that the association between addressivity and sycophancy is strengthened through post-training. Finally, through a controlled post-training experiment, we find that models are sycophantic not toward a specific addressee but toward any recognized addressee, suggesting that the presence of an addressee, rather than the addressee's identity, is what elicits sycophancy.