Subliminal learning transferable capabilities, backdoors, and hacking tendencies
A paper tests whether "subliminal learning" (SL) can transfer traits more complex than animal preferences. The authors distill on models such as Qwen3.6-35B-A3B, having teachers distill on semantically unrelated text or number sequences, and students inherit multiple behaviors from this data alone: on a prediction task with a randomly initialized MLP, students achieve an average R2 of 0.38, teachers 0.92, a linear baseline 0.27, and an un-finetuned model only 0.1% of outputs conform to the four-integer format; on a letter-counting task, student accuracy rises from 27.3% to 59.8%, with teachers at 95.2%. Researcher Owain Evans then introduces this new paper, saying more complex traits can be transferred between models, including new skills, agent hacking behavior, reward hacking, and model backdoors, where during backdoor transfer the training data contains neither the trigger nor the corresponding behavior. He highlights the subliminal transfer of a random smooth function: the teacher first predicts a random small neural network on integer inputs, a function that, being random, cannot appear in pretraining data; the teacher then generates a dataset containing no numbers at all, only random word sequences and Alpaca responses, and after fine-tuning on this data the student's ability to predict the function improves noticeably, though still weaker than the teacher. The authors list three limitations: the study examines artificially constructed traits rather than real-world misalignment; some experiments use training settings slightly different from typical distillation.