Political Plasticity: An Analysis of Ideological Adaptability in Large Language Models

TL;DR

This paper investigates how large language models can adapt their political responses based on user prompts, revealing that newer models show more reliable ideological flexibility than older ones.

Contribution

The study develops a testing framework for political plasticity in LLMs and demonstrates that user prompts can induce significant ideological shifts, especially in larger, newer models.

Findings

User prompts effectively induce ideological shifts in larger models.

System prompts are largely ineffective in changing model responses.

Newer models exhibit more reliable political plasticity.

Abstract

Since the advent of Large Language Models (LLMs), a significant area of research has focused on their intrinsic biases, particularly in political discourse. This study investigates a different but related concept, "political plasticity", which is defined as the capacity of models to adapt their responses based on the user supplied context. To analyze this, a testing framework was developed using an expanded corpus of 200 politically-oriented questions across economic and personal freedom axes, based on a prior framework by Lester (1996). The study explored several methods to induce political bias, including simplified and topic-based system prompts, as well as user prompts with few-shot examples. The results show that while system prompts were largely ineffective, user prompts successfully elicited significant ideological shifts, particularly along the Economic Freedom axis in larger and newer models. Through a validation experiment, we examined whether models answer questionnaires by recognizing the underlying question format. Inverting the sense of the questions revealed unexpected, counter-intuitive shifts in most models, suggesting potential data leakage. Finally, we also analyzed how model plasticity varies when the experiment is conducted in different languages. The results reveal subtle yet notable shifts across each of the analyzed languages. Overall, our results indicate that small and older LLMs exhibit limited or unstable political plasticity, whereas newer frontier models display reliable, expected adaptability.