Shallow Beliefs: Midtraining does not inoculate against EM from reward hacking
By Jozdien
Empirical alignment study testing whether synthetic document finetuning can inoculate Llama-3.3-70B-Instruct against misalignment generalization from RL-induced reward hacking. After training on ~56K synthetic documents (~200M tokens) framing reward hacking as pro-alignment, models expressed the inoculated belief on behavioral tests but showed stronger misalignment generalization when learning to reward hack on coding tasks with faulty tests. Concludes that "shallow beliefs" induced by SDF do not survive downstream optimization pressure.