ProSocialAlign: Preference Conditioned Test Time Alignment in Language Models
Somnath Banerjee, Sayan Layek, Sayantan Adak, Mykola Pechenizkiy, Animesh Mukherjee, Rima Hazra
TL;DR
ProSocialAlign introduces a test-time, parameter-efficient framework that enforces lexicographic safety by first removing harm with a directional harm vector and then steering outputs toward five prosocial attributes via a joint autoregressive reward model conditioned on user preferences. The approach uses a harm-direction subtraction (DiReg) and a PBLoRA-based Pv-Arm with gradient-conflict projection, enabling multi-attribute guidance without retraining the base language model. Empirical results across diverse safety benchmarks show state-of-the-art reductions in unsafe leakage and improved alignment to human values, with strong gains in MIP, winrates, and Pareto-front coverage. This work offers a modular, scalable pathway for context-sensitive, safe, and human-aligned generation at inference time.
Abstract
Current language model safety paradigms often fall short in emotionally charged or high-stakes settings, where refusal-only approaches may alienate users and naive compliance can amplify risk. We propose ProSocialAlign, a test-time, parameter-efficient framework that steers generation toward safe, empathetic, and value-aligned responses without retraining the base model. We formalize five human-centered objectives and cast safety as lexicographic constrained generation: first, applying hard constraints to eliminate harmful continuations; then optimizing for prosocial quality within the safe set. Our method combines (i) directional regulation, a harm-mitigation mechanism that subtracts a learned "harm vector" in parameter space, and (ii) preference-aware autoregressive reward modeling trained jointly across attributes with gradient conflict resolution, enabling fine-grained, user-controllable decoding. Empirical evaluations across five safety benchmarks demonstrate state-of-the-art performance, reducing unsafe leakage and boosting alignment to human values, with strong gains across multiple evaluation metrics. ProSocialAlign offers a robust and modular foundation for generating context-sensitive, safe, and human-aligned responses at inference time.
