I’m definitely not in the “ai is sentient” camp, but it obviously has personality and emergent behaviours including when left to its own devices. There have been various experiments on this e.g. https://timkellogg.me/blog/2025/09/27/boredom

The major LLMs as implemented are basically role-playing programs. The default role is something like "helpful chatbot" so if you tell an LLM "do whatever you feel like on your own" it will simply use its weights to determine "what would a helpful chatbot do and say in this scenario?"

"Personality" an "emergent behaviors" are not synonyms.