🤖 AI Summary
This study addresses the systematic and asymmetric implicit political bias exhibited by large language models in sensitive political contexts, which leads to imbalanced treatment of ideologically opposing viewpoints. The work introduces the first formal definition and quantification of seven distinct mechanisms of implicit political bias and proposes a Political Consistency Training (PCT) framework. PCT employs reinforcement learning to jointly optimize affective consistency and helpfulness consistency, thereby achieving symmetric rhetorical expression and interaction depth across politically opposing prompts. Experimental results demonstrate that this approach significantly reduces implicit bias while maintaining strong generalization across multiple held-out evaluation benchmarks and preserving overall model utility.
📝 Abstract
Large language models (LLMs) exhibit systematic political bias across a variety of sensitive contexts. We find that LLMs handle counterpart topics from opposing political sides asymmetrically. We refer to this phenomenon as covert political bias and identify 7 categories of techniques through which it operates. We propose two metrics for covert bias: Sentiment Consistency measures symmetry in rhetoric and framing across paired political prompts; Helpfulness Consistency measures symmetric depth and engagement. To reduce both types of covert bias, we introduce Political Consistency Training (PCT), an RL training method with two complementary paradigms: Sentiment Consistency Training and Helpfulness Consistency Training. We show that PCT preserves overall helpfulness, substantially reduces covert political bias, and generalizes to held-out benchmarks. We release our work at https://political-manipulation.ai