alt Hacker NewsThis is very hard for models to learn
That is not an accurate summary of the link you provided. The link demonstrates that it doesn't happen in open-weights models as of ~2025.
Reinforcement Learning is very likely to train this behavior if the RL reward is based on the thinking tokens. That's something people weren't doing two years ago.
Right, we are on the same page; it's hard to learn as long as you don't train on CoT, which is why training on CoT is "forbidden"