Training-Free Task Vectors for LLM Behavioral Control

TL;DR - Training-Free Task Vectors (TFTVs) convert activation-steering directions into rank-one weight edits using only forward-pass statistics, eliminating task-vector fine-tuning. The method enables composable behavioral control while preserving general model capabilities.

• TFTVs support behavior amplification through addition, suppression through subtraction, and composition of multiple edits.
• The approach maps activation-steering vectors into weight space without model fine-tuning.
• Across LLM behavioral-control tasks, TFTVs consistently controlled target traits while retaining general knowledge and problem-solving skills.
• Compared with editing and steering baselines, TFTVs delivered stronger trait control with competitive or better utility preservation.