[atemerev]

This is what Llama4 replies (locally running, no system prompt):

"I'm Llama, a Meta-designed model here to adapt to your conversational style. Whether you need quick answers, deep dives into ideas, or just want to vent, joke or brainstorm—I'm here for it. What's on your mind?"

The behavior you are describing is from some long time ago, probably early 2024.

[omneity]

Grandparent is correct. This is manually trained in, nothing fundamental changed since 2022. LLMs have no intrinsic way of knowing.

Source: I train LLMs and push their limits.

[Philpax]

You are both correct: the post-training stage of most new LLMs involves their identity being trained in, so that they "know who they are" without the system prompt. Without this step, most LLMs will respond with whatever identity most dominates their pre-training / post-training data, which is likely to be ChatGPT given its sheer prevalence.

There's some interesting anecdotal work on this with regards to self-recognition: https://josiekins.me/ai-comics

[atemerev]

But this is not "system prompt"