Claude vs Gemma 4: Who Stays in Character Longer?

Claude vs Gemma 4: The Self-Control Showdown

Developers at Mnemara decided to pit Claude against Gemma 4: they gave both models the same "role doc" for self-monitoring and watched who'd break character first. Spoiler: one was a disciplined soldier, the other a free-spirited artist.

Mnemara is an open-source agent runtime where the role doc is re-read on every API call and pinned in context. Think of it as constantly reminding an employee of their job description — except the employee is an LLM. Claude stuck to the script like a seasoned actor, while Gemma 4 started improvising after a few rounds.

What Was Tested

• Self-monitoring: how well the model follows its assigned role (e.g., "you're a security expert, answer strictly by protocol").
• Drift resistance: after N messages, does it still know who it is?
• Speed & cost: Gemma 4 is lighter, but is it cheaper?

Results: Claude held its role for 40+ messages without flinching; Gemma started "forgetting" around message 10. However, Gemma 4 was faster and cost peanuts — perfect for simple tasks where strict role adherence isn't critical.

Who Should Care If you're building an agent that must follow instructions to the letter (e.g., support automation, content moderation), Claude is your pick. If your task is creative and budget matters, Gemma 4 will save you money and headaches.

METABYTE studio comment: We love testing models too — especially when they try to convince us a bug is a feature. But choosing the right LLM is like choosing a framework: some swear by monoliths, others by microservices. Just don't let your CI fail.